{"id":55436,"date":"2026-06-24T04:55:35","date_gmt":"2026-06-24T04:55:35","guid":{"rendered":"https:\/\/zobai.com\/?p=55436"},"modified":"2026-06-24T04:55:37","modified_gmt":"2026-06-24T04:55:37","slug":"threaded-safety-valve-vs-flanged-safety-valve","status":"publish","type":"post","link":"https:\/\/zobai.com\/es\/blog\/threaded-safety-valve-vs-flanged-safety-valve\/","title":{"rendered":"V\u00e1lvula de seguridad roscada frente a v\u00e1lvula de seguridad bridada: Qu\u00e9 deben confirmar los compradores"},"content":{"rendered":"\n<style> .zobai-threaded-flanged-page{ --z-primary:#0f766e; --z-primary-dark:#0b4f49; --z-accent:#14b8a6; --z-text:#1f2933; --z-muted:#5f6b75; --z-line:#dfe7e7; --z-soft:#f0fdfa; --z-soft-2:#f8fafc; --z-warning:#fff7ed; --z-radius-md:16px; --z-radius-lg:24px; --z-shadow:0 12px 30px rgba(15,118,110,.08); --z-container:1180px; color:var(--z-text); line-height:1.72; font-family:inherit; overflow-wrap:break-word; } .zobai-threaded-flanged-page a{color:var(--z-primary);text-decoration:none;border-bottom:1px solid rgba(15,118,110,.28)} .zobai-threaded-flanged-page a:hover{color:var(--z-primary-dark);border-bottom-color:var(--z-primary-dark)} .zobai-threaded-flanged-page a:focus-visible{outline:3px solid rgba(20,184,166,.32);outline-offset:3px;border-radius:5px} .zobai-threaded-flanged-page .zobai-wrap{max-width:var(--z-container);margin:0 auto;padding:0 20px} .zobai-threaded-flanged-page .zobai-hero{margin:0 0 30px;padding:38px;border:1px solid var(--z-line);border-radius:var(--z-radius-lg);background:linear-gradient(135deg,#e7f8f4 0%,#ffffff 58%,#f7fbfa 100%);box-shadow:var(--z-shadow)} .zobai-threaded-flanged-page .zobai-eyebrow{display:inline-flex;margin:0 0 12px;padding:6px 12px;border-radius:999px;border:1px solid rgba(15,118,110,.18);background:#fff;color:var(--z-primary-dark);font-size:14px;font-weight:800} .zobai-threaded-flanged-page h2{margin:34px 0 14px;color:var(--z-primary-dark);font-size:clamp(24px,3vw,36px);line-height:1.22;letter-spacing:-.02em} .zobai-threaded-flanged-page .zobai-hero h2{margin:0 0 16px;font-size:clamp(30px,4vw,52px);letter-spacing:-.03em} .zobai-threaded-flanged-page h3{margin:24px 0 10px;color:#1f3d3a;font-size:22px;line-height:1.3} .zobai-threaded-flanged-page p{margin:0 0 16px} .zobai-threaded-flanged-page ul,.zobai-threaded-flanged-page ol{margin:0 0 18px 22px;padding:0} .zobai-threaded-flanged-page li{margin:7px 0} .zobai-threaded-flanged-page .zobai-meta{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px} .zobai-threaded-flanged-page .zobai-meta span{display:inline-flex;align-items:center;padding:7px 11px;border:1px solid var(--z-line);border-radius:999px;background:#fff;color:var(--z-muted);font-size:14px} .zobai-threaded-flanged-page .zobai-figure{margin:26px 0;border:1px solid var(--z-line);border-radius:var(--z-radius-md);background:#fff;overflow:hidden;box-shadow:0 8px 22px rgba(31,41,51,.05)} .zobai-threaded-flanged-page .zobai-figure img{display:block;width:100%;max-width:100%;height:auto} .zobai-threaded-flanged-page .zobai-figure figcaption{padding:14px 18px 16px;color:#334155;font-size:15px;font-weight:700} .zobai-threaded-flanged-page .zobai-toc,.zobai-threaded-flanged-page .zobai-box,.zobai-threaded-flanged-page .zobai-callout,.zobai-threaded-flanged-page .zobai-warning{margin:26px 0;padding:22px;border:1px solid var(--z-line);border-radius:var(--z-radius-md);background:#fff} .zobai-threaded-flanged-page .zobai-box{background:var(--z-soft);border-left:5px solid var(--z-primary)} .zobai-threaded-flanged-page .zobai-warning{background:var(--z-warning)} .zobai-threaded-flanged-page .zobai-callout{background:var(--z-soft-2)} .zobai-threaded-flanged-page .zobai-toc strong{display:block;margin-bottom:10px;color:var(--z-primary-dark)} .zobai-threaded-flanged-page .zobai-toc ul{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 22px;margin:0;padding-left:20px} .zobai-threaded-flanged-page section{scroll-margin-top:90px} .zobai-threaded-flanged-page .zobai-table-wrap{margin:24px 0;overflow-x:auto;-webkit-overflow-scrolling:touch;border:1px solid var(--z-line);border-radius:var(--z-radius-md);background:#fff} .zobai-threaded-flanged-page .zobai-table{width:100%;min-width:980px;border-collapse:collapse} .zobai-threaded-flanged-page .zobai-table th{padding:13px 14px;background:#0f766e!important;color:#fff!important;text-align:left;font-weight:800;vertical-align:top} .zobai-threaded-flanged-page .zobai-table td{padding:13px 14px;border-bottom:1px solid var(--z-line);vertical-align:top;overflow-wrap:anywhere} .zobai-threaded-flanged-page .zobai-table tr:last-child td{border-bottom:0} .zobai-threaded-flanged-page .zobai-faq details{margin:12px 0;padding:16px 18px;border:1px solid var(--z-line);border-radius:var(--z-radius-md);background:#fff} .zobai-threaded-flanged-page .zobai-faq summary{cursor:pointer;font-weight:800;color:var(--z-primary-dark)} .zobai-threaded-flanged-page .zobai-faq summary:focus-visible{outline:3px solid rgba(20,184,166,.32);outline-offset:4px;border-radius:6px} .zobai-threaded-flanged-page .zobai-cta{margin:42px 0 10px;padding:32px;border-radius:var(--z-radius-lg);background:linear-gradient(135deg,#0b4f49,#0f766e);color:#fff} .zobai-threaded-flanged-page .zobai-cta h2,.zobai-threaded-flanged-page .zobai-cta p,.zobai-threaded-flanged-page .zobai-cta li{color:#fff} .zobai-threaded-flanged-page .zobai-btns{display:flex;flex-wrap:wrap;gap:12px;margin-top:20px} .zobai-threaded-flanged-page .zobai-btn{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:11px 18px;border-radius:999px;background:#fff;color:var(--z-primary-dark);font-weight:800;border-bottom:0} .zobai-threaded-flanged-page .zobai-btn:hover{background:#f0fdfa;color:var(--z-primary-dark)} .zobai-threaded-flanged-page .zobai-btn-secondary{background:transparent;color:#fff;border:1px solid rgba(255,255,255,.68)} .zobai-threaded-flanged-page .zobai-btn-secondary:hover{background:rgba(255,255,255,.1);color:#fff} .zobai-threaded-flanged-page .zobai-cta a{border-bottom:0} @media (max-width:900px){ .zobai-threaded-flanged-page .zobai-wrap{padding:0 18px} .zobai-threaded-flanged-page .zobai-hero{padding:28px} .zobai-threaded-flanged-page .zobai-toc ul{grid-template-columns:1fr} } @media (max-width:640px){ .zobai-threaded-flanged-page .zobai-wrap{padding:0 16px} .zobai-threaded-flanged-page .zobai-hero{padding:22px;border-radius:var(--z-radius-md)} .zobai-threaded-flanged-page h3{font-size:20px} .zobai-threaded-flanged-page .zobai-meta span,.zobai-threaded-flanged-page .zobai-btn{width:100%} .zobai-threaded-flanged-page .zobai-toc,.zobai-threaded-flanged-page .zobai-box,.zobai-threaded-flanged-page .zobai-callout,.zobai-threaded-flanged-page .zobai-warning,.zobai-threaded-flanged-page .zobai-cta{padding:20px} .zobai-threaded-flanged-page .zobai-table{min-width:840px} } <\/style>\n\n<article class=\"zobai-threaded-flanged-page\"> <div class=\"zobai-wrap\">\n\n<section class=\"zobai-hero\" id=\"hero\">\n  <p class=\"zobai-eyebrow\">Safety Valve Connection Selection Guide<\/p>\n  <h2>Threaded or Flanged Safety Valve? Confirm the Connection Before RFQ<\/h2>\n  <p>A threaded safety valve uses a threaded connection on the inlet, outlet or both sides. A flanged safety valve uses a bolted flange connection with a gasket, flange facing and bolting arrangement. The choice is not only a matter of size or appearance. Buyers must confirm whether the valve can physically connect, seal correctly, fit the installation space, match the pressure-temperature conditions and satisfy the project specification.<\/p>\n  <p>This guide helps engineers, procurement teams and maintenance users compare threaded and flanged connection requirements before requesting a quotation from ZOBAI. It should be used together with the actual protected equipment, relief scenario, medium, operating pressure, MAWP or design pressure, set pressure, required relieving capacity, relieving temperature, material, installation space and document requirements.<\/p>\n  <div class=\"zobai-meta\">\n    <span>Primary keyword: threaded safety valve vs flanged safety valve<\/span>\n    <span>Buyer stage: Evaluation \/ RFQ \/ Procurement<\/span>\n    <span>Purpose: Connection and RFQ validation<\/span>\n  <\/div>\n<\/section>\n\n<figure class=\"zobai-figure\" data-image-status=\"complete\" data-image-slot=\"image-01-hero\">\n  <img fetchpriority=\"high\" src=\"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-vs-flanged-safety-valve-hero.webp\" alt=\"Threaded safety valve vs flanged safety valve buyer comparison illustration for connection type confirmation\" title=\"Threaded vs flanged safety valve connection comparison\" width=\"1200\" height=\"900\" loading=\"eager\" fetchpriority=\"high\" decoding=\"async\">\n  <figcaption>Threaded and flanged safety valves require different connection, sealing, installation and RFQ confirmation data before quotation.<\/figcaption>\n<\/figure>\n\n<nav class=\"zobai-toc\" aria-label=\"On this page\">\n  <strong>On this page<\/strong>\n  <ul>\n    <li><a href=\"#quick-answer\">Quick answer<\/a><\/li>\n    <li><a href=\"#connection-name-not-enough\">Why connection name is not enough<\/a><\/li>\n    <li><a href=\"#preliminary-decision-matrix\">Decision matrix<\/a><\/li>\n    <li><a href=\"#threaded-safety-valve\">Threaded safety valves<\/a><\/li>\n    <li><a href=\"#flanged-safety-valve\">Flanged safety valves<\/a><\/li>\n    <li><a href=\"#comparison-table\">Comparison table<\/a><\/li>\n    <li><a href=\"#connection-mistakes\">Connection mistakes<\/a><\/li>\n    <li><a href=\"#connection-vs-selection\">Connection data vs selection data<\/a><\/li>\n    <li><a href=\"#threaded-confirmation\">Threaded connection confirmation<\/a><\/li>\n    <li><a href=\"#flanged-confirmation\">Flanged connection confirmation<\/a><\/li>\n    <li><a href=\"#installation-space\">Installation space<\/a><\/li>\n    <li><a href=\"#pressure-temperature-medium\">Pressure, temperature and medium<\/a><\/li>\n    <li><a href=\"#replacement-workflow\">Replacement workflow<\/a><\/li>\n    <li><a href=\"#rfq-checklist\">RFQ checklist<\/a><\/li>\n    <li><a href=\"#standards-documents\">Standards and documents<\/a><\/li>\n    <li><a href=\"#cta\">Engineering review<\/a><\/li>\n    <li><a href=\"#faq\">FAQ<\/a><\/li>\n    <li><a href=\"#technical-review-focus\">Technical review focus<\/a><\/li>\n  <\/ul>\n<\/nav>\n\n<section id=\"quick-answer\" class=\"zobai-box\">\n  <h2>Quick Answer: Threaded vs Flanged Safety Valves<\/h2>\n  <p>A threaded safety valve may be considered when the equipment or piping connection is threaded and the service conditions, installation space and project requirements allow it. A flanged safety valve may be required when the site piping uses flanges, the project specification requires a flange standard, or the buyer needs bolted assembly, gasket control and clearer maintenance access.<\/p>\n  <p>Connection type alone is not a complete safety valve specification. A buyer still needs to confirm protected equipment, relief scenario, medium and phase, operating pressure, MAWP or design pressure, set pressure, required relieving capacity, relieving temperature, material, inlet and outlet arrangement, inlet pressure loss risk, outlet piping, back pressure if applicable, and required documents.<\/p>\n  <p>For product-family context, review ZOBAI <a href=\"https:\/\/zobai.com\/safety-valves\/\">safety valves<\/a>, <a href=\"https:\/\/zobai.com\/safety-valves\/threaded-safety-valves\/\">threaded safety valves<\/a> and <a href=\"https:\/\/zobai.com\/safety-valves\/flanged-safety-valves\/\">flanged safety valves<\/a>.<\/p>\n<\/section>\n\n<section id=\"connection-name-not-enough\">\n  <h2>Why Buyers Cannot Select by Connection Type Name Alone<\/h2>\n  <p>A common RFQ problem is that buyers describe only the connection style. They may write \u201cthreaded safety valve\u201d or \u201cflanged safety valve\u201d without providing the actual connection standard, rating, sealing method or installation layout. This creates quotation uncertainty and can lead to wrong parts, repeated clarification, installation delay or leakage during pressure test.<\/p>\n  <p>A safety valve connection must be treated as part of the complete pressure protection system. The connection must fit the equipment or piping, but the valve must also meet the required safety duty. A valve that fits mechanically may still be wrong if the set pressure, required capacity, medium, temperature or material is incorrect.<\/p>\n  <h3>Connection Name Does Not Define the Standard<\/h3>\n  <p>\u201cThreaded\u201d does not tell the supplier whether the connection uses a specific thread standard, size, gender or sealing method. \u201cFlanged\u201d does not tell the supplier whether the flange follows ASME, EN, DIN, JIS or another project standard. It also does not confirm pressure class, PN rating, facing type, bolt pattern, gasket or bolting requirements.<\/p>\n  <h3>Connection Size Does Not Prove Relieving Capacity<\/h3>\n  <p>Connection size is not the same as required relieving capacity. A safety valve with a larger connection does not automatically provide the correct capacity, and a valve with the same nominal inlet size does not automatically have the same flow performance. Capacity selection depends on the relief scenario, fluid properties, relieving pressure, relieving temperature, selected valve design and manufacturer data.<\/p>\n  <h3>Installation Space and Maintenance Access Can Change the Decision<\/h3>\n  <p>A threaded connection may appear compact, but it still needs wrench access, thread engagement space, outlet orientation and safe discharge routing. A flanged connection may require a larger installation envelope, but it can provide clear bolting, gasket replacement and disassembly access. For broader site-fit issues, see ZOBAI\u2019s <a href=\"https:\/\/zobai.com\/blog\/safety-valve-selection-guide\/\">safety valve selection guide<\/a>.<\/p>\n<\/section>\n\n<section id=\"preliminary-decision-matrix\">\n  <h2>Preliminary Connection Decision Matrix<\/h2>\n  <p>The matrix below is a buyer-side screening tool. It does not replace project engineering review. It helps identify which connection direction may be more practical before the RFQ is finalized.<\/p>\n  <div class=\"zobai-table-wrap\">\n    <table class=\"zobai-table\">\n      <thead>\n        <tr>\n          <th>Buyer Condition<\/th>\n          <th>Threaded Safety Valve May Be Considered When<\/th>\n          <th>Flanged Safety Valve May Be Considered When<\/th>\n          <th>Data Still Required Before Selection<\/th>\n        <\/tr>\n      <\/thead>\n      <tbody>\n        <tr>\n          <td>Existing site connection<\/td>\n          <td>The protected equipment or piping has a confirmed threaded port.<\/td>\n          <td>The piping specification uses mating flanges.<\/td>\n          <td>Photos, drawings, connection standard, inlet\/outlet details.<\/td>\n        <\/tr>\n        <tr>\n          <td>Installation space<\/td>\n          <td>Compact space is available but wrench access and thread engagement are still possible.<\/td>\n          <td>Enough envelope exists for flange diameter, bolts, nuts, gasket and maintenance tools.<\/td>\n          <td>Installation layout, surrounding equipment, discharge direction.<\/td>\n        <\/tr>\n        <tr>\n          <td>Maintenance approach<\/td>\n          <td>Replacement is infrequent and thread damage risk can be managed.<\/td>\n          <td>Bolted removal, gasket replacement or easier disassembly is preferred.<\/td>\n          <td>Maintenance access, lifting\/support plan, spare gasket\/bolting requirements.<\/td>\n        <\/tr>\n        <tr>\n          <td>Connection sealing<\/td>\n          <td>The thread standard and sealing method are confirmed and suitable for the medium.<\/td>\n          <td>The gasket, facing and bolting method are defined by the project.<\/td>\n          <td>Seal material, gasket material, temperature, medium compatibility.<\/td>\n        <\/tr>\n        <tr>\n          <td>Project documentation<\/td>\n          <td>The project accepts the threaded connection and its inspection scope.<\/td>\n          <td>The project requires a defined flange standard, rating\/class and document package.<\/td>\n          <td>Applicable standard, test records, material certificates, inspection scope.<\/td>\n        <\/tr>\n      <\/tbody>\n    <\/table>\n  <\/div>\n  <div class=\"zobai-warning\">\n    <p><strong>Selection boundary:<\/strong> This matrix only supports preliminary RFQ direction. Final valve selection still depends on the actual protected equipment, relief scenario, medium, operating pressure, MAWP\/design pressure, set pressure, required relieving capacity, relieving temperature, materials, manufacturer data, applicable standard version, project specification and local regulatory requirements.<\/p>\n  <\/div>\n<\/section>\n\n<section id=\"threaded-safety-valve\">\n  <h2>What Is a Threaded Safety Valve?<\/h2>\n  <p>A threaded safety valve is a safety valve supplied with threaded inlet, threaded outlet or threaded inlet and outlet connections. It is selected when the protected equipment, piping or skid connection requires a threaded interface. The key buyer issue is not only whether the valve is threaded, but which thread standard, size, gender and sealing method are required.<\/p>\n  <h3>Thread Standard, Size and Male \/ Female Connection<\/h3>\n  <p>A complete threaded safety valve RFQ should specify the thread standard, nominal thread size and male or female connection. The inlet and outlet should be confirmed separately. The inlet connection is especially important because it connects the valve to the protected equipment or pressure source.<\/p>\n  <h3>Thread Sealant, Tape, Gasket or O-Ring?<\/h3>\n  <p>Threaded connections may seal in different ways depending on the thread type and design. Some threaded connections may use a project-approved thread sealant or tape. Others may require a gasket, O-ring, washer, bonded seal or sealing face. The sealing material must be compatible with the medium, pressure, temperature and project specification.<\/p>\n  <h3>When Threaded Safety Valves Need Extra Verification<\/h3>\n  <p>Extra verification is needed when the existing valve has no clear datasheet, the field connection is old or modified, the valve is installed with adapters, the thread standard is not shown on the nameplate, or the project requires specific documents or inspection records.<\/p>\n<\/section>\n\n<section id=\"flanged-safety-valve\">\n  <h2>What Is a Flanged Safety Valve?<\/h2>\n  <p>A flanged safety valve is a safety valve supplied with flanged inlet, flanged outlet or flanged inlet and outlet connections. The valve connects to the piping system through a bolted flange joint, typically involving a mating flange, gasket, bolting and a defined flange facing.<\/p>\n  <h3>Flange Standard, Size and Pressure Class<\/h3>\n  <p>A flanged safety valve RFQ should specify the flange standard, nominal size, pressure class or PN rating and mating flange requirement. A buyer should not only say \u201cDN50 flanged valve\u201d or \u201c2 inch flange.\u201d The supplier needs to know the standard and rating basis used by the project. For flanged pressure-relief valve RFQ context, see ZOBAI\u2019s <a href=\"https:\/\/zobai.com\/standards\/api-526-flanged-safety-valves\/\">API 526 flanged safety valves<\/a> guide.<\/p>\n  <h3>Gasket, Facing and Bolting Are Part of the Connection<\/h3>\n  <p>A flanged connection is a sealing system, not only a metal flange. The gasket type, gasket material, flange facing and bolting requirements affect whether the joint can seal correctly. The buyer should confirm whether the project requires raised face, flat face, ring-type joint or another facing type, depending on the piping specification and service condition.<\/p>\n  <h3>Why Flanged Safety Valves Usually Need More Space<\/h3>\n  <p>A flanged safety valve usually requires more installation space than a threaded valve because the flange diameter, bolts, nuts, gasket alignment and tooling clearance must be considered. Maintenance teams also need space to remove bolts, replace gaskets and lift or support the valve safely.<\/p>\n<\/section>\n\n<section id=\"comparison-table\">\n  <h2>Threaded Safety Valve vs Flanged Safety Valve Comparison Table<\/h2>\n  <p>The following table gives a buyer-side comparison. It is not a final selection rule. It helps clarify which information must be confirmed before ZOBAI can review the RFQ.<\/p>\n\n  <figure class=\"zobai-figure\" data-image-status=\"complete\" data-image-slot=\"image-02-connection-comparison\">\n    <img loading=\"lazy\" src=\"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-flanged-safety-valve-connection-comparison.webp\" alt=\"Engineering diagram comparing threaded and flanged safety valve connection confirmation points\" title=\"Threaded and flanged safety valve connection confirmation diagram\" width=\"1200\" height=\"900\" loading=\"lazy\" decoding=\"async\">\n    <figcaption>Connection type alone is not enough; buyers must confirm thread or flange details, sealing method and service data before RFQ.<\/figcaption>\n  <\/figure>\n\n  <div class=\"zobai-table-wrap\">\n    <table class=\"zobai-table\">\n      <thead>\n        <tr>\n          <th>Comparison Item<\/th>\n          <th>Threaded Safety Valve<\/th>\n          <th>Flanged Safety Valve<\/th>\n          <th>Buyer Must Confirm<\/th>\n          <th>Risk If Missing<\/th>\n        <\/tr>\n      <\/thead>\n      <tbody>\n        <tr>\n          <td>Connection type<\/td>\n          <td>Threaded inlet, outlet or both<\/td>\n          <td>Flanged inlet, outlet or both<\/td>\n          <td>Whether the site requires threaded or flanged connection<\/td>\n          <td>Wrong physical interface<\/td>\n        <\/tr>\n        <tr>\n          <td>Connection details<\/td>\n          <td>Thread standard, size, male\/female, inlet\/outlet<\/td>\n          <td>Flange standard, size, class\/PN, facing, bolt pattern<\/td>\n          <td>Complete connection specification<\/td>\n          <td>No-fit, leakage or repeated clarification<\/td>\n        <\/tr>\n        <tr>\n          <td>Sealing method<\/td>\n          <td>Thread sealant, tape, gasket, O-ring or project method depending on design<\/td>\n          <td>Gasket, facing and bolting arrangement<\/td>\n          <td>Sealing method and material compatibility<\/td>\n          <td>Leakage during installation or pressure test<\/td>\n        <\/tr>\n        <tr>\n          <td>Installation space<\/td>\n          <td>Often compact, but needs wrench access and thread engagement<\/td>\n          <td>Larger envelope, needs bolt access and flange alignment<\/td>\n          <td>Installation envelope, orientation and access<\/td>\n          <td>Cannot install or maintain safely<\/td>\n        <\/tr>\n        <tr>\n          <td>Replacement risk<\/td>\n          <td>Wrong thread\/gender can prevent installation<\/td>\n          <td>Wrong flange standard\/class\/facing\/bolt pattern can prevent assembly<\/td>\n          <td>Nameplate, drawings, photos and old purchase record<\/td>\n          <td>Wrong replacement valve<\/td>\n        <\/tr>\n        <tr>\n          <td>Pressure-temperature rating<\/td>\n          <td>Must be checked against valve design, material and service<\/td>\n          <td>Must be checked against flange rating, material and service<\/td>\n          <td>Operating pressure, temperature, body material, rating basis<\/td>\n          <td>Unsuitable pressure-temperature selection<\/td>\n        <\/tr>\n        <tr>\n          <td>Capacity and safety duty<\/td>\n          <td>Connection size does not prove capacity<\/td>\n          <td>Flange size does not prove capacity<\/td>\n          <td>Required relieving capacity and basis<\/td>\n          <td>Valve may fit but not protect the equipment<\/td>\n        <\/tr>\n      <\/tbody>\n    <\/table>\n  <\/div>\n<\/section>\n\n<section id=\"connection-mistakes\">\n  <h2>Common Connection Mistakes and Consequences<\/h2>\n  <p>Most connection-related RFQ mistakes come from treating a visible connection feature as a complete valve specification. The table below shows common errors and what buyers should confirm instead.<\/p>\n  <div class=\"zobai-table-wrap\">\n    <table class=\"zobai-table\">\n      <thead>\n        <tr>\n          <th>Common Mistake<\/th>\n          <th>Possible Consequence<\/th>\n          <th>Correct Buyer Confirmation<\/th>\n          <th>ZOBAI Review Trigger<\/th>\n        <\/tr>\n      <\/thead>\n      <tbody>\n        <tr>\n          <td>Requesting \u201cthreaded safety valve\u201d only<\/td>\n          <td>Wrong thread standard, wrong gender or wrong sealing method<\/td>\n          <td>Thread standard, size, male\/female, inlet\/outlet and sealing method<\/td>\n          <td>Unknown thread or replacement without datasheet<\/td>\n        <\/tr>\n        <tr>\n          <td>Requesting \u201cflanged safety valve\u201d only<\/td>\n          <td>Wrong flange standard, pressure class, facing or bolt pattern<\/td>\n          <td>Flange standard, size, class\/PN, facing, gasket and bolting<\/td>\n          <td>Unknown mating flange or strict project piping specification<\/td>\n        <\/tr>\n        <tr>\n          <td>Using connection size as capacity proof<\/td>\n          <td>Valve may physically fit but fail the required relief duty<\/td>\n          <td>Required relieving capacity and capacity basis<\/td>\n          <td>Capacity missing or relief scenario not defined<\/td>\n        <\/tr>\n        <tr>\n          <td>Ignoring installation envelope<\/td>\n          <td>Valve cannot be tightened, bolted, removed or discharged safely<\/td>\n          <td>Layout drawing, photos, access clearance and discharge route<\/td>\n          <td>Skid, compact package or replacement with limited space<\/td>\n        <\/tr>\n        <tr>\n          <td>Assuming connection standard proves certification<\/td>\n          <td>Document package may not meet project approval requirements<\/td>\n          <td>Applicable valve standard, inspection scope and document list<\/td>\n          <td>Project requires certificates, test reports or witness inspection<\/td>\n        <\/tr>\n      <\/tbody>\n    <\/table>\n  <\/div>\n<\/section>\n\n<section id=\"connection-vs-selection\">\n  <h2>Connection Data vs Safety Valve Selection Data<\/h2>\n  <p>Threaded vs flanged is a connection decision, but safety valve selection is a pressure protection decision. Buyers should separate the RFQ into three groups: connection data, service data and document data.<\/p>\n  <h3>Connection Data Confirms Fit and Sealing<\/h3>\n  <p>Connection data confirms whether the valve can be physically installed and sealed. For threaded valves, this includes thread standard, thread size, male or female connection, inlet\/outlet arrangement and sealing method. For flanged valves, this includes flange standard, size, class or PN rating, facing, bolt pattern, gasket and bolting.<\/p>\n  <h3>Service Data Confirms Pressure Protection Duty<\/h3>\n  <p>Service data confirms whether the valve can protect the equipment. This includes protected equipment, relief scenario, medium and phase, operating pressure, MAWP or design pressure, set pressure, required relieving capacity, relieving temperature, inlet pressure loss risk, outlet piping and back pressure if applicable, and material requirements.<\/p>\n  <h3>Document Data Confirms Project Approval Requirements<\/h3>\n  <p>Document data confirms what the buyer needs for project approval, inspection and record keeping. This may include material certificates, set pressure calibration records, pressure test reports, seat tightness test reports, inspection release documents and compliance declarations where applicable.<\/p>\n<\/section>\n\n<section id=\"threaded-confirmation\">\n  <h2>Threaded Connection Confirmation: Thread, Gender and Sealing Method<\/h2>\n  <p>Threaded safety valve RFQs require precise connection details. The connection cannot be confirmed from the word \u201cthreaded\u201d alone.<\/p>\n\n  <figure class=\"zobai-figure\" data-image-status=\"complete\" data-image-slot=\"image-03-threaded-connection-detail\">\n    <img loading=\"lazy\" src=\"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-safety-valve-thread-gender-sealing-detail.webp\" alt=\"Threaded safety valve connection detail showing thread standard male female thread and sealing method confirmation\" title=\"Threaded safety valve thread gender and sealing detail\" width=\"1200\" height=\"900\" loading=\"lazy\" decoding=\"async\">\n    <figcaption>For threaded safety valves, buyers should confirm thread standard, male or female connection, inlet and outlet thread details and sealing method.<\/figcaption>\n  <\/figure>\n\n  <h3>Male Thread vs Female Thread<\/h3>\n  <p>Male thread and female thread are not interchangeable. The buyer must specify whether the inlet and outlet are male or female. For replacement, photos should show both the valve connection and the mating equipment or pipe connection.<\/p>\n  <h3>Inlet Thread vs Outlet Thread<\/h3>\n  <p>The inlet and outlet may have different connection requirements. The inlet is part of the pressure-containing path from the protected equipment. The outlet may connect to discharge piping, venting, a muffler, a safe discharge location or an open discharge arrangement depending on the application.<\/p>\n  <h3>Sealant Cannot Compensate for the Wrong Connection<\/h3>\n  <p>Using additional sealant, tape or force is not a safe solution for the wrong thread. If the thread standard or gender is wrong, the connection should be corrected. For site layout and piping context, see ZOBAI\u2019s <a href=\"https:\/\/zobai.com\/engineering\/safety-valve-installation-guide\/\">safety valve installation guide<\/a>.<\/p>\n<\/section>\n\n<section id=\"flanged-confirmation\">\n  <h2>Flanged Connection Confirmation: Standard, Gasket and Bolting<\/h2>\n  <p>Flanged safety valve RFQs require complete flange information. A flanged connection can fail to match even when the nominal size appears correct.<\/p>\n\n  <figure class=\"zobai-figure\" data-image-status=\"complete\" data-image-slot=\"image-04-flanged-gasket-bolting-detail\">\n    <img loading=\"lazy\" src=\"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/flanged-safety-valve-gasket-bolting-facing-detail.webp\" alt=\"Flanged safety valve connection detail showing flange standard gasket facing bolt pattern and bolting confirmation\" title=\"Flanged safety valve gasket bolting and facing detail\" width=\"1200\" height=\"900\" loading=\"lazy\" decoding=\"async\">\n    <figcaption>A flanged safety valve RFQ should confirm flange standard, pressure class or PN rating, facing, gasket, bolt pattern and bolting requirements.<\/figcaption>\n  <\/figure>\n\n  <h3>Flange Standard and Pressure Class<\/h3>\n  <p>The RFQ should identify the flange standard and pressure class or PN rating. The mating flange and valve flange must be compatible. If the flange standard is unknown, the buyer should send the piping specification, equipment drawing or clear photos of the existing valve and flange.<\/p>\n  <h3>Facing, Gasket and Bolt Pattern<\/h3>\n  <p>The flange facing, gasket type and bolt pattern must match the mating connection. A mismatch can prevent assembly or cause leakage. Gasket selection also depends on medium, temperature, pressure and project specification. For flange dimension context, see <a href=\"https:\/\/zobai.com\/standards\/asme-b16-5-flange-dimensions\/\">ASME B16.5 flange dimensions<\/a>.<\/p>\n  <h3>Why \u201cDN50 Flange\u201d Is Not Enough<\/h3>\n  <p>\u201cDN50 flange\u201d or \u201c2 inch flange\u201d only identifies a nominal size. It does not identify the flange standard, rating\/class, facing, bolt pattern, gasket type or bolting requirement. It also does not prove the valve capacity.<\/p>\n<\/section>\n\n<section id=\"installation-space\">\n  <h2>Installation Space, Maintenance Access and Replacement Risk<\/h2>\n  <p>Connection type affects installation and maintenance. A buyer should review site layout before deciding whether a threaded or flanged safety valve is appropriate.<\/p>\n\n  <figure class=\"zobai-figure\" data-image-status=\"complete\" data-image-slot=\"image-05-installation-space-comparison\">\n    <img loading=\"lazy\" src=\"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-flanged-safety-valve-installation-space-comparison.webp\" alt=\"Installation space comparison for threaded and flanged safety valves showing wrench access bolt clearance and maintenance envelope\" title=\"Threaded and flanged safety valve installation space comparison\" width=\"1200\" height=\"900\" loading=\"lazy\" decoding=\"async\">\n    <figcaption>Connection selection should consider wrench access, bolt clearance, outlet direction, maintenance space and discharge piping layout.<\/figcaption>\n  <\/figure>\n\n  <h3>Compact Does Not Always Mean Easier<\/h3>\n  <p>Threaded valves may be compact, but they still need space for wrench access, correct thread engagement, sealant application if required and safe orientation. A compact connection can still be difficult if the valve is close to a wall, skid frame, instrument tubing or discharge piping.<\/p>\n  <h3>Bolt Access and Gasket Replacement<\/h3>\n  <p>Flanged connections need enough clearance for bolts, nuts, tools and gasket replacement. If the valve is close to another component, it may be difficult to align the flange, insert bolts or remove the valve during maintenance.<\/p>\n  <h3>Outlet Piping, Support and Back Pressure Review<\/h3>\n  <p>If the outlet is piped, manifolded, routed to a header or connected to a long discharge line, the outlet arrangement may require additional review. Heavy outlet piping should not be left unsupported by the valve body. Discharge direction, drainage, reaction force, safe venting and superimposed or built-up back pressure can affect the valve configuration and installation requirements. If outlet piping is connected to a header or manifold, back pressure review may be required before final valve configuration.<\/p>\n  <h3>Existing Valve Photos Reduce RFQ Risk<\/h3>\n  <p>For replacement, buyers should send photos of the full valve body, nameplate, inlet connection, outlet connection, mating pipe or equipment connection, surrounding installation space, discharge piping, adapters, reducers and supports if present.<\/p>\n<\/section>\n\n<section id=\"pressure-temperature-medium\">\n  <h2>Pressure, Temperature, Medium and Material Still Control Final Selection<\/h2>\n  <p>The final choice between threaded and flanged safety valves cannot be made by connection type alone. The valve must match the pressure relief duty and service environment.<\/p>\n  <h3>Set Pressure Is Not the Same as Connection Rating<\/h3>\n  <p>Set pressure is the pressure at which the safety valve is adjusted to open. Flange class, PN rating or thread connection rating does not automatically define set pressure. Buyers should provide operating pressure, MAWP or design pressure and required set pressure separately.<\/p>\n  <h3>Required Relieving Capacity Is Not Proven by Connection Size<\/h3>\n  <p>Required relieving capacity depends on the governing relief scenario, medium, relieving pressure, relieving temperature and selected valve design. Connection size alone cannot prove capacity. A valve with a certain threaded or flanged connection still needs capacity review against manufacturer data. For sizing context, see ZOBAI\u2019s <a href=\"https:\/\/zobai.com\/standards\/api-520-safety-valve-sizing\/\">API 520 safety valve sizing<\/a> guide.<\/p>\n  <h3>Medium and Temperature Affect Material, Seat and Gasket Selection<\/h3>\n  <p>Medium and temperature affect body material, seat material, seal material, gasket material, spring material and trim selection. Steam, gas, liquid, corrosive service, high temperature service and dirty service may require different construction details. For broader rating context, review ZOBAI\u2019s <a href=\"https:\/\/zobai.com\/standards\/pressure-temperature-ratings\/\">pressure-temperature ratings<\/a> guide.<\/p>\n<\/section>\n\n<section id=\"replacement-workflow\">\n  <h2>Replacement Workflow Before RFQ<\/h2>\n  <p>Replacement buyers often start with an old valve and a short request such as \u201csame as existing.\u201d This is not enough for a safety valve replacement. The existing valve may not have been correctly selected, the service conditions may have changed, or the original documentation may be missing.<\/p>\n  <h3>Check the Nameplate and Existing Datasheet<\/h3>\n  <p>The nameplate may show size, set pressure, material, model reference or manufacturer information. The old datasheet or purchase order may show connection type, flange standard, thread standard, material, test requirements and document scope.<\/p>\n  <h3>Photograph the Connection and Installation Space<\/h3>\n  <p>Photos should show the valve from multiple angles. For threaded valves, include the thread connection and mating connection. For flanged valves, include the flange, bolts, gasket area, mating flange and surrounding space.<\/p>\n  <h3>Mark Unknown Items as \u201cTo Be Confirmed\u201d<\/h3>\n  <p>Unknown data should not be guessed. If the buyer does not know the flange standard, thread standard, set pressure, required capacity, material or document requirement, it should be marked as \u201cto be confirmed.\u201d<\/p>\n<\/section>\n\n<section id=\"rfq-checklist\">\n  <h2>RFQ \/ Selection Parameters Checklist for Threaded or Flanged Safety Valves<\/h2>\n  <p>A complete RFQ should include connection data, service data and document data. The following checklist can be used before sending a request to ZOBAI.<\/p>\n\n  <figure class=\"zobai-figure\" data-image-status=\"complete\" data-image-slot=\"image-06-rfq-checklist\">\n    <img loading=\"lazy\" src=\"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-flanged-safety-valve-rfq-checklist.webp\" alt=\"RFQ checklist for threaded and flanged safety valves including connection data service data material and document requirements\" title=\"Threaded and flanged safety valve RFQ checklist\" width=\"1200\" height=\"900\" loading=\"lazy\" decoding=\"async\">\n    <figcaption>A complete RFQ should include connection data, service data, material requirements, installation constraints and document requirements.<\/figcaption>\n  <\/figure>\n\n  <div class=\"zobai-table-wrap\">\n    <table class=\"zobai-table\">\n      <thead>\n        <tr>\n          <th>Parameter<\/th>\n          <th>What to Provide<\/th>\n          <th>Why It Matters<\/th>\n          <th>Missing Data Risk<\/th>\n        <\/tr>\n      <\/thead>\n      <tbody>\n        <tr><td>Protected equipment<\/td><td>Vessel, tank, compressor, pipeline, skid, pump outlet or other equipment<\/td><td>Defines what the valve protects<\/td><td>Wrong protection basis<\/td><\/tr>\n        <tr><td>Relief scenario<\/td><td>Thermal expansion, blocked outlet, regulator failure, fire case, process upset or project-defined scenario<\/td><td>Supports safety duty and capacity review<\/td><td>Incorrect selection assumption<\/td><\/tr>\n        <tr><td>Medium and phase<\/td><td>Gas, vapor, steam, liquid, two-phase, corrosive, dirty or special service<\/td><td>Affects sizing, materials, seat\/seal and discharge<\/td><td>Wrong material or valve configuration<\/td><\/tr>\n        <tr><td>Pressure data<\/td><td>Operating pressure, MAWP\/design pressure and set pressure<\/td><td>Separates service pressure, equipment basis and valve opening pressure<\/td><td>Wrong spring, setting or pressure basis<\/td><\/tr>\n        <tr><td>Required relieving capacity<\/td><td>Flow rate and calculation basis if available<\/td><td>Needed for final sizing and valve selection<\/td><td>Valve may fit but fail safety duty<\/td><\/tr>\n        <tr><td>Relieving temperature<\/td><td>Temperature during the relieving condition<\/td><td>Affects material, seal, gasket and pressure-temperature suitability<\/td><td>Wrong material or rating assumption<\/td><\/tr>\n        <tr><td>Threaded connection data<\/td><td>Thread standard, size, male\/female, inlet\/outlet and sealing method<\/td><td>Confirms threaded fit and sealing<\/td><td>Wrong thread, leakage or no-fit<\/td><\/tr>\n        <tr><td>Flanged connection data<\/td><td>Flange standard, size, class\/PN, facing, bolt pattern, gasket and bolting<\/td><td>Confirms flanged fit and sealing<\/td><td>Bolt mismatch, gasket issue or leakage<\/td><\/tr>\n        <tr><td>Installation data<\/td><td>Space limits, orientation, discharge direction, maintenance access and outlet piping<\/td><td>Confirms site fit and safe discharge routing<\/td><td>Cannot install or maintain safely<\/td><\/tr>\n        <tr><td>Back pressure \/ outlet piping<\/td><td>State whether the outlet is open, piped, manifolded or subject to superimposed pressure<\/td><td>May affect configuration, stability and discharge review<\/td><td>Wrong outlet arrangement or unreviewed back pressure<\/td><\/tr>\n        <tr><td>Materials<\/td><td>Body, bonnet, seat, seal, spring, trim and gasket requirements<\/td><td>Affects service compatibility<\/td><td>Corrosion, leakage or unsuitable service<\/td><\/tr>\n        <tr><td>Documents<\/td><td>Test report, material certificate, set pressure record, inspection scope and standard requirement<\/td><td>Defines approval and delivery documents<\/td><td>Missing documents or approval delay<\/td><\/tr>\n      <\/tbody>\n    <\/table>\n  <\/div>\n<\/section>\n\n<section id=\"standards-documents\">\n  <h2>Standards and Documentation Buyers May Need to Confirm<\/h2>\n  <p>Connection standards, safety valve standards and project specifications are related but not the same. A buyer should not assume that naming a flange standard or thread type completes the safety valve specification.<\/p>\n  <h3>Connection Standard Is Not the Same as Safety Valve Standard<\/h3>\n  <p>A thread or flange standard defines the connection interface. A safety valve standard or project specification may define other requirements such as pressure setting, capacity documentation, testing, material records, inspection scope and marking.<\/p>\n  <h3>Flange Standard Does Not Prove Valve Certification<\/h3>\n  <p>A flanged valve may use a certain flange standard, but that does not automatically prove that the valve has a specific certification or approval for every project. Compliance and certification depend on the selected model, manufacturing scope, testing, documentation and project requirements.<\/p>\n  <h3>Request Documents Clearly at RFQ Stage<\/h3>\n  <p>Document requirements should be stated before quotation. These may include material certificate, hydrostatic or shell test report, set pressure calibration record, seat tightness report if required, inspection release note, datasheet and nameplate information. For standards navigation, see ZOBAI\u2019s <a href=\"https:\/\/zobai.com\/standards\/\">safety valve standards<\/a> page.<\/p>\n<\/section>\n\n<section id=\"cta\" class=\"zobai-cta\">\n  <h2>Ask ZOBAI to Review Your Connection and Operating Parameters<\/h2>\n  <p>Before choosing a threaded or flanged safety valve, send ZOBAI both the connection details and the operating conditions. A complete RFQ helps the engineering team check whether the inquiry is clear enough for quotation and whether additional data is required before selection.<\/p>\n  <ul>\n    <li>Connection type: threaded or flanged.<\/li>\n    <li>Thread standard, size, male\/female connection and sealing method if threaded.<\/li>\n    <li>Flange standard, size, class\/rating, facing, gasket and bolting if flanged.<\/li>\n    <li>Protected equipment and relief scenario.<\/li>\n    <li>Medium and phase.<\/li>\n    <li>Operating pressure, MAWP\/design pressure and set pressure.<\/li>\n    <li>Required relieving capacity and capacity basis if available.<\/li>\n    <li>Relieving temperature, material and document requirements.<\/li>\n    <li>Installation envelope, discharge direction, outlet piping and back pressure condition if applicable.<\/li>\n    <li>Existing valve photos, nameplate, datasheet or drawing for replacement.<\/li>\n  <\/ul>\n  <p>ZOBAI can review the submitted parameter set before quotation. Final safety valve selection depends on the real operating conditions, relief scenario, manufacturer data, applicable standard version, project specification and local regulatory requirements.<\/p>\n  <div class=\"zobai-btns\">\n    <a class=\"zobai-btn\" href=\"https:\/\/zobai.com\/ask-an-engineer\/\">Ask a Safety Valve Engineer<\/a>\n    <a class=\"zobai-btn zobai-btn-secondary\" href=\"https:\/\/zobai.com\/contacts\/\">Send RFQ Parameters<\/a>\n  <\/div>\n<\/section>\n\n<section id=\"faq\" class=\"zobai-faq\">\n  <h2>FAQ About Threaded vs Flanged Safety Valves<\/h2>\n  <details><summary>What is the difference between a threaded safety valve and a flanged safety valve?<\/summary><p>A threaded safety valve uses threaded connections, while a flanged safety valve uses bolted flange connections with gasket and bolting requirements. The buyer must confirm connection standard, size, sealing method, installation space, pressure-temperature rating, medium, material and documents.<\/p><\/details>\n  <details><summary>When should buyers choose a threaded safety valve?<\/summary><p>A threaded safety valve may be considered when the equipment or piping connection is threaded and the service conditions, project specification, installation space and document requirements allow it. Buyers must still confirm thread standard, size, male\/female connection, sealing method and service data before quotation.<\/p><\/details>\n  <details><summary>When should buyers choose a flanged safety valve?<\/summary><p>A flanged safety valve may be needed when the piping specification requires flanged connections, when maintenance access favors bolted disassembly, or when the project requires a defined flange standard, facing, gasket and bolting arrangement.<\/p><\/details>\n  <details><summary>Is a threaded safety valve suitable for high pressure service?<\/summary><p>It depends on the selected valve design, connection detail, material, service temperature, applicable standard and project specification. Threaded connection type alone does not prove pressure suitability.<\/p><\/details>\n  <details><summary>Does flange size prove safety valve capacity?<\/summary><p>No. Flange size does not prove safety valve capacity. Capacity depends on the required relieving load, relief scenario, fluid properties, relieving pressure, relieving temperature, valve design and manufacturer data.<\/p><\/details>\n  <details><summary>What flange information should I send for a flanged safety valve RFQ?<\/summary><p>Send the flange standard, nominal size, pressure class or PN rating, facing type, bolt pattern, gasket requirement, bolting requirement, mating flange details and project piping specification if available.<\/p><\/details>\n  <details><summary>What thread information should I send for a threaded safety valve RFQ?<\/summary><p>Send the thread standard, nominal thread size, male or female connection, inlet and outlet thread details, sealing method, field piping connection and existing valve photos if it is a replacement.<\/p><\/details>\n  <details><summary>Why does ZOBAI need gasket and bolting information?<\/summary><p>For flanged connections, the gasket, flange facing and bolting are part of the sealing system. If gasket or bolting requirements are missing, the quotation may not match the project specification or the valve may not be installable as expected.<\/p><\/details>\n  <details><summary>Can I replace a threaded valve with a flanged valve?<\/summary><p>Possibly, but not by connection name alone. Replacing a threaded valve with a flanged valve may require piping modification, space review, new mating flange, gasket, bolting, discharge arrangement and engineering approval.<\/p><\/details>\n  <details><summary>What documents should I request before ordering a safety valve?<\/summary><p>Document requirements may include datasheet, material certificate, set pressure calibration record, test report, inspection record, seat tightness report if required and applicable standard declaration where confirmed. The exact document package should be stated at RFQ stage.<\/p><\/details>\n<\/section>\n\n<section id=\"technical-review-focus\" class=\"zobai-box\">\n  <h2>Technical Review Focus<\/h2>\n  <p>The technical review focus for this page is RFQ communication around threaded and flanged safety valve connection selection. The reviewed engineering boundaries include connection type, thread or flange data, sealing method, set pressure versus MAWP\/design pressure, connection size versus required relieving capacity, installation envelope, outlet piping, back pressure review trigger, material inputs and document requirements.<\/p>\n  <p>This page does not verify a specific valve model, certification scope, certified relieving capacity or project approval. Those items must be confirmed against the selected valve model, manufacturer data, applicable standard version, project specification and local regulatory requirements.<\/p>\n<\/section>\n\n<section class=\"zobai-box\">\n  <h2>Engineering Note<\/h2>\n  <p>This article supports buyer communication and RFQ preparation. It does not replace project engineering review, manufacturer datasheet verification, formal relief calculation, code review or local regulatory approval. Final selection depends on actual operating conditions, relief scenario, manufacturer data, applicable standard version, project specification and local regulatory requirements.<\/p>\n<\/section>\n\n<\/div> <\/article>\n\n<script type=\"application\/ld+json\"> { \"@context\":\"https:\/\/schema.org\", \"@graph\":[ { \"@type\":\"TechArticle\", \"@id\":\"https:\/\/www.zobai.com\/en\/threaded-safety-valve-vs-flanged-safety-valve\/#techarticle\", \"headline\":\"Threaded Safety Valve vs Flanged Safety Valve: What Buyers Should Confirm\", \"description\":\"Compare threaded and flanged safety valves. Confirm connection type, flange standard, gasket, bolting, thread details, pressure, temperature and RFQ data before ordering.\", \"url\":\"https:\/\/www.zobai.com\/en\/threaded-safety-valve-vs-flanged-safety-valve\/\", \"mainEntityOfPage\":\"https:\/\/www.zobai.com\/en\/threaded-safety-valve-vs-flanged-safety-valve\/\", \"inLanguage\":\"en\", \"articleSection\":\"Safety Valve Connection Selection\", \"image\":[ \"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-vs-flanged-safety-valve-hero.webp\", \"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-flanged-safety-valve-connection-comparison.webp\", \"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-safety-valve-thread-gender-sealing-detail.webp\", \"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/flanged-safety-valve-gasket-bolting-facing-detail.webp\", \"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-flanged-safety-valve-installation-space-comparison.webp\", \"https:\/\/zobai.com\/wp-content\/uploads\/2026\/06\/threaded-flanged-safety-valve-rfq-checklist.webp\" ], \"author\":{\"@type\":\"Organization\",\"name\":\"ZOBAI\",\"url\":\"https:\/\/zobai.com\/\"}, \"publisher\":{\"@type\":\"Organization\",\"name\":\"ZOBAI\",\"url\":\"https:\/\/zobai.com\/\"}, \"about\":[\"threaded safety valve vs flanged safety valve\",\"threaded safety valve\",\"flanged safety valve\",\"safety valve connection type\",\"pressure relief valve connection\",\"flange standard\",\"gasket and bolting\",\"RFQ checklist\"] }, { \"@type\":\"BreadcrumbList\", \"@id\":\"https:\/\/www.zobai.com\/en\/threaded-safety-valve-vs-flanged-safety-valve\/#breadcrumb\", \"itemListElement\":[ {\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/zobai.com\/\"}, {\"@type\":\"ListItem\",\"position\":2,\"name\":\"Safety Valves\",\"item\":\"https:\/\/zobai.com\/safety-valves\/\"}, {\"@type\":\"ListItem\",\"position\":3,\"name\":\"Threaded Safety Valve vs Flanged Safety Valve\",\"item\":\"https:\/\/www.zobai.com\/en\/threaded-safety-valve-vs-flanged-safety-valve\/\"} ] }, { \"@type\":\"FAQPage\", \"@id\":\"https:\/\/www.zobai.com\/en\/threaded-safety-valve-vs-flanged-safety-valve\/#faq\", \"mainEntity\":[ {\"@type\":\"Question\",\"name\":\"What is the difference between a threaded safety valve and a flanged safety valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"A threaded safety valve uses threaded connections, while a flanged safety valve uses bolted flange connections with gasket and bolting requirements. The buyer must confirm connection standard, size, sealing method, installation space, pressure-temperature rating, medium, material and documents.\"}}, {\"@type\":\"Question\",\"name\":\"When should buyers choose a threaded safety valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"A threaded safety valve may be considered when the equipment or piping connection is threaded and the service conditions, project specification, installation space and document requirements allow it. Buyers must still confirm thread standard, size, male or female connection, sealing method and service data before quotation.\"}}, {\"@type\":\"Question\",\"name\":\"When should buyers choose a flanged safety valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"A flanged safety valve may be needed when the piping specification requires flanged connections, when maintenance access favors bolted disassembly, or when the project requires a defined flange standard, facing, gasket and bolting arrangement.\"}}, {\"@type\":\"Question\",\"name\":\"Is a threaded safety valve suitable for high pressure service?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"It depends on the selected valve design, connection detail, material, service temperature, applicable standard and project specification. Threaded connection type alone does not prove pressure suitability.\"}}, {\"@type\":\"Question\",\"name\":\"Does flange size prove safety valve capacity?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. Flange size does not prove safety valve capacity. Capacity depends on the required relieving load, relief scenario, fluid properties, relieving pressure, relieving temperature, valve design and manufacturer data.\"}}, {\"@type\":\"Question\",\"name\":\"What flange information should I send for a flanged safety valve RFQ?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Send the flange standard, nominal size, pressure class or PN rating, facing type, bolt pattern, gasket requirement, bolting requirement, mating flange details and project piping specification if available.\"}}, {\"@type\":\"Question\",\"name\":\"What thread information should I send for a threaded safety valve RFQ?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Send the thread standard, nominal thread size, male or female connection, inlet and outlet thread details, sealing method, field piping connection and existing valve photos if it is a replacement.\"}}, {\"@type\":\"Question\",\"name\":\"Why does ZOBAI need gasket and bolting information?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"For flanged connections, the gasket, flange facing and bolting are part of the sealing system. If gasket or bolting requirements are missing, the quotation may not match the project specification or the valve may not be installable as expected.\"}}, {\"@type\":\"Question\",\"name\":\"Can I replace a threaded valve with a flanged valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Possibly, but not by connection name alone. Replacing a threaded valve with a flanged valve may require piping modification, space review, new mating flange, gasket, bolting, discharge arrangement and engineering approval.\"}}, {\"@type\":\"Question\",\"name\":\"What documents should I request before ordering a safety valve?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Document requirements may include datasheet, material certificate, set pressure calibration record, test report, inspection record, seat tightness report if required and applicable standard declaration where confirmed. The exact document package should be stated at RFQ stage.\"}} ] } ] } <\/script>\n","protected":false},"excerpt":{"rendered":"<p>Safety Valve Connection Selection Guide Threaded or Flanged Safety Valve? Confirm the Connection Before RFQ A threaded safety valve uses a threaded connection on the inlet, outlet or both sides. A flanged safety valve uses a bolted flange connection with a gasket, flange facing and bolting arrangement. The choice is not only a matter of&#8230;<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-55436","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/posts\/55436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/types\/post"}],"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=55436"}],"version-history":[{"count":1,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/posts\/55436\/revisions"}],"predecessor-version":[{"id":55443,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/posts\/55436\/revisions\/55443"}],"wp:attachment":[{"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/media?parent=55436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/categories?post=55436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zobai.com\/es\/wp-json\/wp\/v2\/tags?post=55436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}