{"id":633,"date":"2026-10-12T10:44:50","date_gmt":"2026-10-12T05:14:50","guid":{"rendered":"https:\/\/www.tescosteel.com\/blog\/?p=633"},"modified":"2026-10-06T10:49:59","modified_gmt":"2026-10-06T05:19:59","slug":"api-6a-type-6bx-flange-design-types-and-key-features","status":"publish","type":"post","link":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/","title":{"rendered":"API 6A Type 6BX Flange: Design, Types and Key Features"},"content":{"rendered":"

Type 6BX flanges connect high-pressure equipment on wellheads, where a single seal failure can shut down a well or trigger a blowout. API Specification 6A defines the design, materials, testing, inspection, dimensional, and functional requirements for this equipment in the petroleum and natural gas industries. These requirements make <\/span>API 6A Type 6BX flanges<\/span><\/a> suitable for demanding wellhead and pressure-control applications. To understand why these flanges are used in such critical service, it is important to examine their design, types, and key features<\/span><\/p>\n

What Is an API 6A Type 6BX Flange?<\/b><\/h2>\n

A Type 6BX flange links pressure-containing wellhead components using a ring-type joint, or RTJ, seal instead of a flat gasket. The metal ring seats into matching grooves on each flange face and deforms under bolt load, creating a seal rated for high working pressures. Wellhead assemblies and associated valves and fittings use this connection when flat-gasket flanges cannot maintain pressure to the required level.<\/span><\/p>\n

Type 6BX differs from Type 6B in pressure-handling capacity, bolting pattern, and gasket compatibility. The two are not interchangeable parts. Buyers should verify the ring groove profile, bolt circle, and pressure class specified for 6BX hardware before pairing it with 6B components, since mismatched flanges compromise the seal even when nominal sizes appear to match.<\/span><\/p>\n

API 6A Type 6BX Flange Design<\/b><\/h2>\n

The RTJ sealing face sits at the center of the Type 6BX flange design. A machined groove receives the metal ring gasket, and the bolt load compresses the ring into both mating grooves to form the pressure seal. Bolt-hole count, bolt circle diameter, and flange outside diameter follow the pressure class and nominal size defined in API 6A.<\/span><\/p>\n

Bore diameter and pressure-containing wall thickness determine how the flange performs under working and test pressure, and these dimensions shift with size and pressure class. Never assume standard pipeline flange geometry applies to 6BX hardware. Check dimensions, ring groove profile and bolt pattern prior to ordering using the current API 6A version. Make sure the mating flange, ring gasket and connecting equipment are of matching pressure class and size.<\/span><\/p>\n

Types of API 6A Type 6BX Flanges<\/b><\/h2>\n

6BX weld-neck flanges connect permanently to pipe or wellhead components through a full-penetration weld, transferring load through the flange body. This configuration suits connections that see repeated pressure cycling or need a smooth internal bore for flow.<\/span><\/p>\n

6BX blind flanges are full-bore flanges that are used to stop the\u2002flow in a pipeline. Blind flanges are used to seal off the openings of a pipe when there is no flow in the pipe, but access is still needed later or to shut it down. Each configuration has a specific function in the assembly and the selection of the correct type depends on whether the connection point passes flow through or ends it.<\/span><\/p>\n

Key Features and Technical Considerations<\/b><\/h2>\n

Type 6BX flange design supports high-pressure wellhead service through RTJ sealing, material selection, and dimensional accuracy working together. The RTJ seal handles pressure classes beyond what flat-gasket connections can sustain. Material selection depends on the service environment: sour service applications require confirming hardness and material limits against the applicable NACE requirements.<\/span><\/p>\n

The pressure rating, nominal size and PSL designation shall match the equipment to which it will be connected, because API 6A defines PSL requirements based on the criticality of the service. Material verification, dimensional checks and hydrostatic or pneumatic testing are performed based on the applicable API 6A edition. The sizing tables have been revised in the current (21st) edition, and the technical requirements have been reorganized from previous editions.<\/span><\/p>\n

How to Select the Right API 6A Type 6BX Flange<\/b><\/h2>\n

Selecting a Type 6BX flange starts with the required nominal size and the working pressure of the system it connects to. From there, confirm the applicable API 6A requirements for that pressure class and size, including PSL and material requirements suited to the service environment.<\/span><\/p>\n

Check RTJ ring and gasket compatibility against the groove profile on both mating flanges, and confirm the mating flange or equipment configuration matches the bolt pattern and pressure class. Request inspection and testing documentation, including material certificates and pressure test records, before accepting delivery. Tesco Steel & Engineering supplies API 6A Type 6BX flanges along with the documentation that procurement teams need to verify compliance with these requirements.<\/span><\/p>\n

API 6A Type 6BX Flange Applications<\/b><\/h2>\n

Type 6BX flanges connect wellhead equipment, Christmas tree assemblies, and other high-pressure well-control components used in oil and gas production. API 6A addresses this equipment, especially for petroleum and natural gas service, covering the connections that isolate, control, and monitor pressure at the wellhead. Applications extend to valves, spools, and adapters within the wellhead assembly, where RTJ sealing maintains pressure integrity.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Type 6BX flanges connect high-pressure equipment on wellheads, where a single seal failure can shut down a well or trigger a blowout. API Specification 6A defines the design, materials, testing, inspection, dimensional, and functional requirements for this equipment in the petroleum and natural gas industries. These requirements make API 6A Type 6BX flanges suitable for […]<\/p>\n","protected":false},"author":2,"featured_media":634,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21],"tags":[120,119,122,117,121,118],"class_list":["post-633","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-flanges-blog","tag-6bx-flange-dimensions","tag-6bx-flange-types","tag-6bx-rtj-flange","tag-api-6a-6bx-flange","tag-api-6bx-flange","tag-type-6bx-flange"],"yoast_head":"\nAPI 6A Type 6BX Flange: Types, Design & Features<\/title>\n<meta name=\"description\" content=\"Explore API 6A Type 6BX flanges, including their design, types, pressure ratings, dimensions, RTJ sealing and key features for high-pressure applications.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"API 6A Type 6BX Flange: Types, Design & Features\" \/>\n<meta property=\"og:description\" content=\"Explore API 6A Type 6BX flanges, including their design, types, pressure ratings, dimensions, RTJ sealing and key features for high-pressure applications.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-10-12T05:14:50+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-10-06T05:19:59+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.tescosteel.com\/blog\/wp-content\/uploads\/2026\/10\/API-6A-Type-6BX-Flange-Types-Design-Features.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1376\" \/>\n\t<meta property=\"og:image:height\" content=\"768\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Tesco Steel & Engineering\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Tesco Steel & Engineering\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"4 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/\",\"url\":\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/\",\"name\":\"API 6A Type 6BX Flange: Types, Design & Features\",\"isPartOf\":{\"@id\":\"https:\/\/www.tescosteel.com\/blog\/#website\"},\"datePublished\":\"2026-10-12T05:14:50+00:00\",\"dateModified\":\"2026-10-06T05:19:59+00:00\",\"author\":{\"@id\":\"https:\/\/www.tescosteel.com\/blog\/#\/schema\/person\/420eeb76f55c9ef0866b377995b61479\"},\"description\":\"Explore API 6A Type 6BX flanges, including their design, types, pressure ratings, dimensions, RTJ sealing and key features for high-pressure applications.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.tescosteel.com\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"API 6A Type 6BX Flange: Design, Types and Key Features\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.tescosteel.com\/blog\/#website\",\"url\":\"https:\/\/www.tescosteel.com\/blog\/\",\"name\":\"\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.tescosteel.com\/blog\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.tescosteel.com\/blog\/#\/schema\/person\/420eeb76f55c9ef0866b377995b61479\",\"name\":\"Tesco Steel & Engineering\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.tescosteel.com\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/14e4108de746b50bff420f29b7e7f9195ead38229a94df7f8e9f84f3506a2d0e?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/14e4108de746b50bff420f29b7e7f9195ead38229a94df7f8e9f84f3506a2d0e?s=96&d=mm&r=g\",\"caption\":\"Tesco Steel & Engineering\"},\"url\":\"https:\/\/www.tescosteel.com\/blog\/author\/giza\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"API 6A Type 6BX Flange: Types, Design & Features","description":"Explore API 6A Type 6BX flanges, including their design, types, pressure ratings, dimensions, RTJ sealing and key features for high-pressure applications.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/","og_locale":"en_US","og_type":"article","og_title":"API 6A Type 6BX Flange: Types, Design & Features","og_description":"Explore API 6A Type 6BX flanges, including their design, types, pressure ratings, dimensions, RTJ sealing and key features for high-pressure applications.","og_url":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/","article_published_time":"2026-10-12T05:14:50+00:00","article_modified_time":"2026-10-06T05:19:59+00:00","og_image":[{"width":1376,"height":768,"url":"https:\/\/www.tescosteel.com\/blog\/wp-content\/uploads\/2026\/10\/API-6A-Type-6BX-Flange-Types-Design-Features.jpg","type":"image\/jpeg"}],"author":"Tesco Steel & Engineering","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Tesco Steel & Engineering","Est. reading time":"4 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/","url":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/","name":"API 6A Type 6BX Flange: Types, Design & Features","isPartOf":{"@id":"https:\/\/www.tescosteel.com\/blog\/#website"},"datePublished":"2026-10-12T05:14:50+00:00","dateModified":"2026-10-06T05:19:59+00:00","author":{"@id":"https:\/\/www.tescosteel.com\/blog\/#\/schema\/person\/420eeb76f55c9ef0866b377995b61479"},"description":"Explore API 6A Type 6BX flanges, including their design, types, pressure ratings, dimensions, RTJ sealing and key features for high-pressure applications.","breadcrumb":{"@id":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.tescosteel.com\/blog\/api-6a-type-6bx-flange-design-types-and-key-features\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.tescosteel.com\/blog\/"},{"@type":"ListItem","position":2,"name":"API 6A Type 6BX Flange: Design, Types and Key Features"}]},{"@type":"WebSite","@id":"https:\/\/www.tescosteel.com\/blog\/#website","url":"https:\/\/www.tescosteel.com\/blog\/","name":"","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.tescosteel.com\/blog\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.tescosteel.com\/blog\/#\/schema\/person\/420eeb76f55c9ef0866b377995b61479","name":"Tesco Steel & Engineering","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.tescosteel.com\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/14e4108de746b50bff420f29b7e7f9195ead38229a94df7f8e9f84f3506a2d0e?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/14e4108de746b50bff420f29b7e7f9195ead38229a94df7f8e9f84f3506a2d0e?s=96&d=mm&r=g","caption":"Tesco Steel & Engineering"},"url":"https:\/\/www.tescosteel.com\/blog\/author\/giza\/"}]}},"_links":{"self":[{"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/posts\/633","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/comments?post=633"}],"version-history":[{"count":1,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/posts\/633\/revisions"}],"predecessor-version":[{"id":635,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/posts\/633\/revisions\/635"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/media\/634"}],"wp:attachment":[{"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/media?parent=633"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/categories?post=633"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tescosteel.com\/blog\/wp-json\/wp\/v2\/tags?post=633"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}