{"id":55100,"date":"2026-06-11T00:08:30","date_gmt":"2026-06-11T00:08:30","guid":{"rendered":"https:\/\/zobai.com\/?page_id=55100"},"modified":"2026-06-11T00:53:58","modified_gmt":"2026-06-11T00:53:58","slug":"glossary-back-pressure","status":"publish","type":"page","link":"https:\/\/zobai.com\/es\/resources\/glossary-back-pressure\/","title":{"rendered":"glosario contrapresi\u00f3n"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"55100\" class=\"elementor elementor-55100\" data-elementor-post-type=\"page\">\n\t\t\t\t<div class=\"elementor-element elementor-element-8dd31e3 e-con-full e-flex cmsmasters-bg-hide-none cmsmasters-bg-hide-none cmsmasters-block-default e-con e-parent\" data-id=\"8dd31e3\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-38fdbe0 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"38fdbe0\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-99611bd cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-shortcode\" data-id=\"99611bd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"shortcode.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-shortcode\"><nav aria-label=\"breadcrumbs\" class=\"rank-math-breadcrumb\"><p><span class=\"last\">Home<\/span><\/p><\/nav><\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6e47791 elementor-widget__width-initial cmsmasters-block-default cmsmasters-sticky-default elementor-invisible elementor-widget elementor-widget-heading\" data-id=\"6e47791\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;_animation&quot;:&quot;cmsmasters-fade-in-up&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h1 class=\"elementor-heading-title elementor-size-default\">What Is Back Pressure in a Safety Valve System?<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2eb9cd0 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"2eb9cd0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p>Back pressure is the pressure at the outlet of a pressure-relief valve. It can already exist before the valve opens, develop because of discharge flow after opening, or include both effects during the relieving event.<br \/><br \/>This glossary page defines superimposed, built-up and total back pressure; explains why the distinction matters to set-pressure behavior, certified capacity, valve stability and reseating; and shows the information that should appear in a PSV datasheet or RFQ.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-aec1f5d e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"aec1f5d\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-1910fbc cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"1910fbc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"#definitions\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Review the Definitions<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-580315b cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"580315b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"\/engineering\/back-pressure-and-bellows\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Open the Engineering Guide<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6c8cce6 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"6c8cce6\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-2070f29 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"2070f29\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-4fe83df cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"4fe83df\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Glossary Quick Links<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0f3fd9c elementor-align-start elementor-icon-list--layout-traditional elementor-list-item-link-full_width cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-icon-list\" data-id=\"0f3fd9c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"icon-list.default\">\n\t\t\t\t\t\t\t<ul class=\"elementor-icon-list-items\">\n\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#definition\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Core definition<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#definitions\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Types of back pressure<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#constant-variable\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Constant vs variable<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#performance\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Why it affects the valve<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#rfq-data\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">What to enter in an RFQ<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#mistakes\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Common mistakes<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#related\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Related engineering pages<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<a href=\"#faq\">\n\n\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-chevron-right\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M285.476 272.971L91.132 467.314c-9.373 9.373-24.569 9.373-33.941 0l-22.667-22.667c-9.357-9.357-9.375-24.522-.04-33.901L188.505 256 34.484 101.255c-9.335-9.379-9.317-24.544.04-33.901l22.667-22.667c9.373-9.373 24.569-9.373 33.941 0L285.475 239.03c9.373 9.372 9.373 24.568.001 33.941z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">FAQ<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-c443802 e-con-full cmsmasters-effect cmsmasters-effect-type-transform e-flex cmsmasters-effect-hover-type-element cmsmasters-block-default e-con e-child\" data-id=\"c443802\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;,&quot;position&quot;:&quot;absolute&quot;,&quot;cms_transform_hover_type&quot;:&quot;element&quot;}\">\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-1f90390 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"1f90390\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-713e140 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"713e140\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-62b29d2 elementor-align-start elementor-icon-list--layout-traditional elementor-list-item-link-full_width cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-icon-list\" data-id=\"62b29d2\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"icon-list.default\">\n\t\t\t\t\t\t\t<ul class=\"elementor-icon-list-items\">\n\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Superimposed back pressure exists before the valve opens.<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Built-up back pressure is generated by relief flow through the outlet system.<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Total back pressure during relief combines the applicable superimposed and built-up components.<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Constant and variable describe the behavior of superimposed back pressure; they are not separate primary categories.<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-8aeb046 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"8aeb046\" data-element_type=\"container\" data-e-type=\"container\" id=\"definition\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-06fd0b7 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"06fd0b7\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-4865c0a cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"4865c0a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Definition<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b3a044f cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"b3a044f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Back pressure is the pressure acting at the valve outlet<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3d5aff6 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"3d5aff6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe outlet pressure may come from a pressurized vessel, flare header, common relief header, scrubber, silencer, closed vent, recovery system or the pressure loss created by the valve\u2019s own discharge flow.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0a2a0d0 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"0a2a0d0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tFor engineering review, the value should be identified by source and timing. A single number labelled only \u201cback pressure\u201d is incomplete because pressure present before opening can affect the valve differently from pressure generated after opening.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-2c89cb4 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"2c89cb4\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e9d8718 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"e9d8718\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Plain-language summary<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c2a11f8 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"c2a11f8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<strong>Before opening:<\/strong> superimposed back pressure.<br><strong>After opening:<\/strong> built-up back pressure.<br><strong>During relief:<\/strong> total back pressure for the applicable case.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-632f650 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"632f650\" data-element_type=\"container\" data-e-type=\"container\" id=\"definitions\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-60863c6 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"60863c6\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-41b0807 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"41b0807\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Types of Back Pressure<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ecdd95d cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"ecdd95d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Use these terms consistently in calculations, datasheets and RFQs<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a273b01 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"a273b01\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe classification should show where the pressure comes from and whether it exists before or after the valve opens.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-bace023 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"bace023\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-7c63bbd e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"7c63bbd\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-0359377 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"0359377\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">01<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c17b336 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"c17b336\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Superimposed Back Pressure<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d199dcd cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"d199dcd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tPressure present at the valve outlet before opening. It may be constant or variable and can come from a pressurized downstream system or common header.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b3f54b3 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"b3f54b3\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-36ec492 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"36ec492\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">02<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0d326b1 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"0d326b1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Built-up Back Pressure<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-712f62b cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"712f62b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tPressure generated after opening as relief flow passes through the tailpipe, fittings, header, silencer, scrubber or other downstream resistance.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-2464837 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"2464837\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-5e090f4 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"5e090f4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">03<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-adf6db0 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"adf6db0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Total Back Pressure<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9c3eda9 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"9c3eda9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe outlet pressure acting during the relieving event. It combines the applicable superimposed and built-up back-pressure components.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b2660ea e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"b2660ea\" data-element_type=\"container\" data-e-type=\"container\" id=\"constant-variable\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-a29f617 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"a29f617\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-481543c cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"481543c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Constant vs Variable<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-80c0559 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"80c0559\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Constant and variable are subtypes of superimposed back pressure<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-64bca5c cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"64bca5c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tConstant superimposed back pressure remains essentially stable over the relevant operating period. Variable superimposed back pressure changes with header operation, other relieving devices, downstream control or process conditions.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9804da8 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"9804da8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe RFQ should record minimum, normal and maximum credible values instead of only one design number.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ea4bcd7 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"ea4bcd7\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-d8e42ef cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"d8e42ef\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Examples<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-28e8187 elementor-align-start elementor-icon-list--layout-traditional elementor-list-item-link-full_width cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-icon-list\" data-id=\"28e8187\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"icon-list.default\">\n\t\t\t\t\t\t\t<ul class=\"elementor-icon-list-items\">\n\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Constant: stable pressure in a receiving vessel or controlled downstream system<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Variable: flare-header pressure changes as other devices relieve<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Variable: closed vent or recovery pressure changes with operating mode<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Variable: common header pressure changes with simultaneous relief cases<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Constant or variable pressure may require cold differential test pressure review<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">The selected valve must be checked against the full credible pressure range<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-fa6bcc8 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"fa6bcc8\" data-element_type=\"container\" data-e-type=\"container\" id=\"performance\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-e3002c3 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"e3002c3\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9711e5a cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"9711e5a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Why It Matters<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e4bb359 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"e4bb359\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Back pressure can change how a safety valve opens, flows and reseats<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2cedfc3 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"2cedfc3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe exact effect depends on valve design, internal areas, service, fluid phase, pressure ratio and certified manufacturer data.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d41fe1c e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"d41fe1c\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-e1c6966 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"e1c6966\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e3a1502 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"e3a1502\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">01<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-77028ee cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"77028ee\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Opening and Set-Pressure Behavior<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a8cc6fb cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"a8cc6fb\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tOutlet pressure can alter the net force acting on a conventional spring-loaded valve and may require set-pressure or CDTP review.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b5aa7a1 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"b5aa7a1\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-4923787 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"4923787\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">02<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-eed451a cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"eed451a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Relieving Capacity<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-59c6866 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"59c6866\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tBack pressure can reduce the available pressure ratio and require a certified correction factor or manufacturer capacity curve.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-c68a3aa e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"c68a3aa\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-29dfeb6 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"29dfeb6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">03<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-49d21bd cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"49d21bd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Lift and Stability<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d39dcde cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"d39dcde\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tExcessive or changing outlet pressure can contribute to incomplete lift, unstable flow, chatter or interaction with the inlet system.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f9296b6 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"f9296b6\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b00ae70 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"b00ae70\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">04<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ac0eafd cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"ac0eafd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Blowdown and Reseating<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-de60e9c cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"de60e9c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tOutlet pressure can change the pressure at which the valve closes and the stability of the reseating process.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-669abb1 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"669abb1\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-eb92c8b cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"eb92c8b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">05<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cdb1826 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"cdb1826\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Valve-Type Selection<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2df5e27 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"2df5e27\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe pressure profile may support a conventional, balanced bellows or pilot-operated design, subject to certified limits.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ef1d7ba e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"ef1d7ba\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-6f319e6 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"6f319e6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">06<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-97328fc cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"97328fc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Outlet-System Design<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9b14af1 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"9b14af1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe piping, flare, vent, scrubber, reaction force, drainage and simultaneous-relief case remain part of the system review.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-7b9e9ce e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"7b9e9ce\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-b454ef0 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"b454ef0\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-47bb302 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"47bb302\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Quick Engineering Workflow<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-41efbba cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"41efbba\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">How back pressure should be documented<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-64084d3 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"64084d3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tUse this short workflow for datasheet and RFQ preparation. Use the full Back Pressure and Bellows guide for valve-type selection.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-c049e77 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"c049e77\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-01c8953 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"01c8953\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-49b7fde cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"49b7fde\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">01<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c5092af cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"c5092af\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Identify the discharge destination<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2691fac cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"2691fac\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tDefine atmosphere, flare header, closed vent, scrubber, silencer, recovery system or pressurized vessel.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-0f8db82 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"0f8db82\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-668be30 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"668be30\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">02<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a260838 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"a260838\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Record pre-opening pressure<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f560277 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"f560277\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tState minimum, normal and maximum superimposed pressure and whether it is constant or variable.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ba6cf34 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"ba6cf34\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a643fc4 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"a643fc4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">03<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d59697e cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"d59697e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Calculate flow-generated pressure<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-94bc9a9 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"94bc9a9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tDetermine built-up pressure at the governing relieving flow and simultaneous-header case.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-9d8b07b e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"9d8b07b\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b8b0199 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"b8b0199\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">04<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c06cb1d cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"c06cb1d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Check the selected valve<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-277668c cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"277668c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tVerify capacity correction, opening behavior, stability, bellows or pilot limits and outlet rating.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-9563a5f e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"9563a5f\" data-element_type=\"container\" data-e-type=\"container\" id=\"rfq-data\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-fd9929d e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"fd9929d\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b8d9df5 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"b8d9df5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a RFQ Data<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f0a85c8 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"f0a85c8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">What to enter for back pressure in a safety valve RFQ<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1e37ce4 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"1e37ce4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tDo not enter only \u201c5 barg back pressure\u201d without stating whether it exists before opening, develops during relief or varies with header conditions.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cb44014 elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"cb44014\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/contacts\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Request Back Pressure Review<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-c165aab e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"c165aab\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-8d14dbd cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"8d14dbd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Recommended RFQ fields<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b810cba elementor-align-start elementor-icon-list--layout-traditional elementor-list-item-link-full_width cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-icon-list\" data-id=\"b810cba\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"icon-list.default\">\n\t\t\t\t\t\t\t<ul class=\"elementor-icon-list-items\">\n\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Discharge destination and system description<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Minimum, normal and maximum superimposed back pressure<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Whether superimposed pressure is constant or variable<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Built-up back pressure at governing relieving flow<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Total back pressure for each credible case<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Outlet piping size, length, fittings and elevation<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Simultaneous relief assumptions for common headers<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Set pressure, allowable overpressure and required capacity<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Fluid composition, phase and relieving temperature<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-check\" viewBox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M173.898 439.404l-166.4-166.4c-9.997-9.997-9.997-26.206 0-36.204l36.203-36.204c9.997-9.998 26.207-9.998 36.204 0L192 312.69 432.095 72.596c9.997-9.997 26.207-9.997 36.204 0l36.203 36.204c9.997 9.997 9.997 26.206 0 36.204l-294.4 294.401c-9.998 9.997-26.207 9.997-36.204-.001z\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">Requested valve type, material and documentation standard<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-5f4bc5a e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"5f4bc5a\" data-element_type=\"container\" data-e-type=\"container\" id=\"mistakes\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-efa0722 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"efa0722\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a642381 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"a642381\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Common Mistakes<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ec55e40 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"ec55e40\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Back-pressure errors that lead to poor valve selection<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8c157c8 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"8c157c8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThese issues should be corrected before the datasheet or purchase order is released.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-497dd6b e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"497dd6b\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-73d6b3e e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"73d6b3e\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a3bb2cf cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"a3bb2cf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">01<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-286b17f cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"286b17f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Using one undefined number<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2ff8354 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"2ff8354\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe supplier cannot tell whether the value is superimposed, built-up or total.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-4a1eed0 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"4a1eed0\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-6a56e74 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"6a56e74\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">02<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ae42db0 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"ae42db0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Treating constant and variable as primary categories<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4b48b3e cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"4b48b3e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThey are behaviors of superimposed back pressure, not replacements for the superimposed\/built-up distinction.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b5a2fda e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"b5a2fda\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-cc000cc cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"cc000cc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">03<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b273553 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"b273553\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Ignoring simultaneous relief<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d26241f cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"d26241f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tA common header may reach its maximum pressure when other devices discharge at the same time.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d717838 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"d717838\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c970ef7 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"c970ef7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">04<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d95639c cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"d95639c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Assuming bellows removes all limits<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e986c9b cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"e986c9b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tCapacity correction, bellows limits, venting and outlet-system design still require verification.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-7a830ed e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"7a830ed\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-fe2eb32 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"fe2eb32\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">05<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b1c8c1b cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"b1c8c1b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Ignoring outlet temperature<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-09bd4cd cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"09bd4cd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThe outlet flange, body and piping must be rated for the credible pressure-temperature condition.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6e117c3 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"6e117c3\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-de2ae11 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"de2ae11\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">06<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-52dbdba cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"52dbdba\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Using nominal pipe size as proof<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4b4fc06 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"4b4fc06\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tPipe size alone does not establish built-up pressure or acceptable valve performance.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-4465c11 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"4465c11\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-482c226 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"482c226\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">07<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-100d67e cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"100d67e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Missing pressure range<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-84e3e28 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"84e3e28\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tVariable back pressure should include minimum, normal and maximum credible values.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-966115b e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"966115b\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-fe398f9 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"fe398f9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">08<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2f779a7 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"2f779a7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Skipping manufacturer data<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5d790a6 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"5d790a6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tAllowable limits and correction factors depend on the certified valve design and service.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-cc0c845 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"cc0c845\" data-element_type=\"container\" data-e-type=\"container\" id=\"related\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-4b1488e e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"4b1488e\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-660807d cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"660807d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a Related Engineering Resources<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2925b3a cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"2925b3a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Continue from the glossary definition to engineering selection<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c85a57a cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"c85a57a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tThese links use current ZOBAI pages already available on the website.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-1646550 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"1646550\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-98fee9e e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"98fee9e\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-559e28b cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"559e28b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">01<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-75eedd6 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"75eedd6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Back Pressure and Bellows<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0673d40 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"0673d40\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tFull engineering guide covering definitions, force balance, bellows limitations and valve-type selection.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c1977e6 elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"c1977e6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/engineering\/back-pressure-and-bellows\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Open Engineering Guide<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-58bc9dc e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"58bc9dc\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-cc62c87 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"cc62c87\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">02<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-749b4a0 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"749b4a0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">High Back Pressure Applications<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6cc7208 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"6cc7208\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tApplication guidance for flare headers, closed systems, scrubbers and variable downstream pressure.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e011c87 elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"e011c87\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/applications\/high-back-pressure\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Open Application<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b8218cf e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"b8218cf\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e27bc9e cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"e27bc9e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">03<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-90f13d5 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"90f13d5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Bellows Balanced Safety Valves<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c6c7852 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"c6c7852\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tProduct-family page for balanced bellows construction, service factors and RFQ information.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1679bbd elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"1679bbd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/safety-valves\/bellows-balanced-safety-valves\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">View Product<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-8150787 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"8150787\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-8373c03 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"8373c03\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-828dcf0 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"828dcf0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">04<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9a3f3ec cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"9a3f3ec\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">API 520 Safety Valve Sizing<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-986a350 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"986a350\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tConnect the outlet-pressure condition with device sizing, selection and certified capacity.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1ea97dc elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"1ea97dc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/standards\/api-520-safety-valve-sizing\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Open API 520 Guide<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ddcebf5 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"ddcebf5\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-1defd8c cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"1defd8c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">05<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3c62080 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"3c62080\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">API 521 Relief Systems<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3feb2fc cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"3feb2fc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tReview flare, vent, depressuring and system-level relief conditions.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-97205cd elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"97205cd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/standards\/api-521-pressure-relief-systems\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Open API 521 Guide<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-53d9780 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"53d9780\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-6a5fb3a cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"6a5fb3a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">06<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e1abd09 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"e1abd09\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Safety Valve Installation<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-89b3d02 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"89b3d02\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tReview outlet piping, supports, reaction force, drainage and commissioning.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2580c2f elementor-align-left cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"2580c2f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/engineering\/safety-valve-installation-guide\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Open Installation Guide<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-977bc1b e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"977bc1b\" data-element_type=\"container\" data-e-type=\"container\" id=\"faq\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-dff5727 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"dff5727\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-c051d31 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"c051d31\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">\u203a\u203a\u203a FAQ<\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2cbea26 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"2cbea26\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Common questions about back pressure<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0b178d1 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-accordion\" data-id=\"0b178d1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"accordion.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-accordion\">\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1161\" class=\"elementor-tab-title\" data-tab=\"1\" role=\"button\" aria-controls=\"elementor-tab-content-1161\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What is back pressure in a safety valve?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1161\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"1\" role=\"region\" aria-labelledby=\"elementor-tab-title-1161\"><p>Back pressure is the pressure at the outlet of a pressure-relief valve. It may exist before opening, develop because of discharge flow after opening, or include both components during relief.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1162\" class=\"elementor-tab-title\" data-tab=\"2\" role=\"button\" aria-controls=\"elementor-tab-content-1162\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What is superimposed back pressure?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1162\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"2\" role=\"region\" aria-labelledby=\"elementor-tab-title-1162\"><p>It is outlet pressure that exists before the valve opens. It may be constant or variable depending on the downstream system.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1163\" class=\"elementor-tab-title\" data-tab=\"3\" role=\"button\" aria-controls=\"elementor-tab-content-1163\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What is built-up back pressure?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1163\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"3\" role=\"region\" aria-labelledby=\"elementor-tab-title-1163\"><p>It is pressure generated after the valve opens because relieving flow passes through outlet piping, fittings, headers or disposal equipment.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1164\" class=\"elementor-tab-title\" data-tab=\"4\" role=\"button\" aria-controls=\"elementor-tab-content-1164\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What is total back pressure?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1164\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"4\" role=\"region\" aria-labelledby=\"elementor-tab-title-1164\"><p>It is the outlet pressure acting during relief and combines the applicable superimposed and built-up components.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1165\" class=\"elementor-tab-title\" data-tab=\"5\" role=\"button\" aria-controls=\"elementor-tab-content-1165\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">Does a balanced bellows valve eliminate back-pressure effects?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1165\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"5\" role=\"region\" aria-labelledby=\"elementor-tab-title-1165\"><p>No. It reduces the pressure-area force effect on the spring-loaded mechanism, but capacity correction, stability, bellows limits, venting and downstream-system pressure still require review.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1166\" class=\"elementor-tab-title\" data-tab=\"6\" role=\"button\" aria-controls=\"elementor-tab-content-1166\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-left\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What back-pressure data should be included in an RFQ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1166\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"6\" role=\"region\" aria-labelledby=\"elementor-tab-title-1166\"><p>State the discharge destination, minimum and maximum superimposed pressure, whether it is constant or variable, built-up pressure at governing flow, total pressure for credible cases and the outlet piping details.<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<script type=\"application\/ld+json\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What is back pressure in a safety valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>Back pressure is the pressure at the outlet of a pressure-relief valve. It may exist before opening, develop because of discharge flow after opening, or include both components during relief.<\\\/p>\"}},{\"@type\":\"Question\",\"name\":\"What is superimposed back pressure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>It is outlet pressure that exists before the valve opens. It may be constant or variable depending on the downstream system.<\\\/p>\"}},{\"@type\":\"Question\",\"name\":\"What is built-up back pressure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>It is pressure generated after the valve opens because relieving flow passes through outlet piping, fittings, headers or disposal equipment.<\\\/p>\"}},{\"@type\":\"Question\",\"name\":\"What is total back pressure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>It is the outlet pressure acting during relief and combines the applicable superimposed and built-up components.<\\\/p>\"}},{\"@type\":\"Question\",\"name\":\"Does a balanced bellows valve eliminate back-pressure effects?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>No. It reduces the pressure-area force effect on the spring-loaded mechanism, but capacity correction, stability, bellows limits, venting and downstream-system pressure still require review.<\\\/p>\"}},{\"@type\":\"Question\",\"name\":\"What back-pressure data should be included in an RFQ?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>State the discharge destination, minimum and maximum superimposed pressure, whether it is constant or variable, built-up pressure at governing flow, total pressure for credible cases and the outlet piping details.<\\\/p>\"}}]}<\/script>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d81f372 e-con-full e-flex cmsmasters-block-default e-con e-parent\" data-id=\"d81f372\" data-element_type=\"container\" data-e-type=\"container\" id=\"glossary-back-pressure-cta\" data-settings=\"{&quot;background_background&quot;:&quot;gradient&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-7e694da e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"7e694da\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-777efe6 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-heading\" data-id=\"777efe6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Need help defining back pressure for a PSV datasheet or RFQ?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4d1f0b7 cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-text-editor\" data-id=\"4d1f0b7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\tSend the relief calculation, valve datasheet, outlet piping and flare or header pressure data. ZOBAI can identify missing inputs and define the next engineering or quotation step.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-57650f0 e-con-full e-flex cmsmasters-block-default e-con e-child\" data-id=\"57650f0\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ad540a5 elementor-align-center cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"ad540a5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/contacts\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Request Engineering Review<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-899c145 elementor-align-center cmsmasters-block-default cmsmasters-sticky-default elementor-widget elementor-widget-button\" data-id=\"899c145\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-md\" href=\"\/ask-an-engineer\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Ask an Engineer<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>What Is Back Pressure in a Safety Valve System? Back pressure is the pressure at the outlet of a pressure-relief valve. It can already exist before the valve opens, develop because of discharge flow after opening, or include both effects during the relieving event. This glossary page defines superimposed, built-up and total back pressure; explains&#8230;<\/p>","protected":false},"author":2,"featured_media":0,"parent":48271,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-55100","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/pages\/55100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/comments?post=55100"}],"version-history":[{"count":7,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/pages\/55100\/revisions"}],"predecessor-version":[{"id":55112,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/pages\/55100\/revisions\/55112"}],"up":[{"embeddable":true,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/pages\/48271"}],"wp:attachment":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/media?parent=55100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}