{"id":6216,"date":"2026-09-20T22:40:59","date_gmt":"2026-09-20T19:40:59","guid":{"rendered":"https:\/\/aesinn.com\/test-ve-olcum-hizmetleri\/asme-b31-3-proses-boru-tesisati-tasarim-imalat-muayene-ve-test-kodunun-bilgilendirici-rehberi\/"},"modified":"2026-09-21T22:09:12","modified_gmt":"2026-09-21T19:09:12","slug":"asme-b31-3-proses-boru-tesisati-tasarim-imalat-muayene-ve-test-kodunun-bilgilendirici-rehberi","status":"publish","type":"page","link":"https:\/\/aesinn.com\/en\/test-ve-olcum-hizmetleri\/asme-b31-3-proses-boru-tesisati-tasarim-imalat-muayene-ve-test-kodunun-bilgilendirici-rehberi\/","title":{"rendered":"ASME B31.3 Process Piping: An Informative Guide to the Design, Manufacture, Inspection and Test Code"},"content":{"rendered":"<h2 class=\"wp-block-heading\">What is ASME B31.3 and what does it cover?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ASME B31.3 is an engineering code published by the American Society of Mechanical Engineers (ASME) that specifies the rules for the design, material selection, manufacture, assembly, inspection, and pressure testing of process piping systems. Typical application areas include industrial facilities where fluids are transported in processes, such as refineries, petrochemical plants, chemical factories, pharmaceutical manufacturing plants, pulp and food processing plants.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The code does not cover building plumbing, power plant main steam lines, or long-distance transmission pipelines. These areas are reserved for other members of the ASME B31 code family. B31.3 brings together in a single framework the design and manufacturing requirements for pressure-limiting components of piping systems (pipes, fittings, flanges, valves, gaskets) and their integrity.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This content is for educational and informational purposes only; application to a specific project should be based on the current version of the relevant code and a qualified engineer&#039;s technical assessment.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Scope: Process piping systems (refinery, petrochemical, chemical, pharmaceutical, food)<\/li>\n\n\n<li>Excluded: building plumbing, power plant steam headers, transmission pipelines.<\/li>\n\n\n<li>Topics covered: design, materials, manufacturing, assembly, inspection, and testing.<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Its place in the ASME B31 Code Family.<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ASME B31 is a family of codes divided according to different service types. Each member prescribes different design and inspection strictness according to the risks of the type of facility it addresses. Choosing the correct code begins with correctly classifying which service and which risk the piping system is exposed to.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Two of the most frequently confused members are B31.1 and B31.3. B31.1 (Power Piping) primarily manages high-temperature and high-pressure steam and condensate lines in power generation plants and district heating and cooling systems; the main risk is physical explosion. B31.3 (Process Piping), on the other hand, focuses on high-temperature, high-pressure, corrosive, and toxic services in refineries and chemical plants; where even a microscopic leak can be dangerous to personnel.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Transmission pipelines are subject to separate regulations: B31.4 covers liquid and sludge transmission pipelines, and B31.8 covers gas transmission and distribution pipelines.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>B31.1 \u2014 Power piping (power plant steam and condensate lines)<\/li>\n\n\n<li>B31.3 \u2014 Process piping (refinery, petrochemical, chemical)<\/li>\n\n\n<li>B31.4 \u2014 Liquid and sludge conveyance pipelines<\/li>\n\n\n<li>B31.8 \u2014 Gas transmission and distribution pipelines<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Fluid Service Categories<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The fundamental principle of ASME B31.3 is to scale the design and inspection rigor according to the hazard level of the fluid being transported. The code divides fluid services into several classes, applying more flexible requirements for lower-hazard services and stricter requirements for higher-hazard services. The responsibility for determining which class a service falls into generally rests with the facility owner.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Category D is the least hazardous class; it is generally used for services that are non-flammable, non-toxic, and remain within specific pressure and temperature limits. Unless otherwise specified, the services are considered Normal Fluid Service; this is the default and most common class of the code. Category M is for toxic services; it covers fluids where even a single exposure can cause serious and irreversible harm and imposes the strictest inspection and testing requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In addition, the code includes specific sections for high pressure and high purity services. These sections introduce additional or modified requirements beyond the standard rules.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Category D \u2014 least hazardous; non-flammable\/toxic, confined to pressure and temperature.<\/li>\n\n\n<li>Normal Fluid Service \u2014 the default class; most process lines are located here.<\/li>\n\n\n<li>Category M \u2014 toxic service; most rigorous inspection and testing.<\/li>\n\n\n<li>High Pressure and High Purity \u2014 additional requirements with special sections<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Distinction between Inspection and Examination<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ASME B31.3 contains a crucial distinction that is often overlooked: the code defines inspection and examination as distinct roles. While these two concepts are easily confused in Turkish, the code designates separate areas of responsibility.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Examination is the responsibility of the manufacturer\/contractor and is carried out by an Examiner who performs non-destructive testing activities; this includes the physical examination of weld seams using methods such as radiography and liquid penetrant testing. Inspection, on the other hand, is the responsibility of the facility owner and is carried out by an Inspector appointed by the owner (Owner&#039;s Inspector); the Inspector verifies that code compliance has been achieved and must possess the necessary qualifications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The practical consequence of this distinction is that the party performing the actual non-destructive testing (Examiner) is different from the party verifying, on behalf of the owner, that the process meets the code requirements (Inspector). Records are expected to be traceable to the relevant weld seam, welder, and Examiner.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Examination \u2014 manufacturer&#039;s responsibility; non-destructive testing is carried out by the Examiner.<\/li>\n\n\n<li>Inspection \u2014 owner&#039;s responsibility; Owner&#039;s Inspector verifies<\/li>\n\n\n<li>Records should be traceable by seam, welder, and examiner.<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Scope of Inspection and Pressure Test<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The scope of inspection varies according to the fluid service class. For Normal Fluid Service, the code prescribes a certain percentage of radiographic or ultrasonic inspections on a random basis at butt welds; this percentage is typically cited as around 5 percent in the literature. The exact percentage should be confirmed from the relevant clauses of the code according to the applied code printout and service class. In more hazardous services, such as Category M, the scope of inspection increases significantly.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A key feature of random inspection is the progressive sampling logic: if a randomly selected weld does not meet the acceptance criteria, additional welds from the same welder&#039;s work are inspected; if failure persists, sampling can be gradually expanded to include the entire work of that welder. This approach aims to reveal whether a single defect indicates a systemic problem.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Once the piping system is completed, its leak tightness is verified by a pressure test. The default method is hydrostatic testing. Under specific conditions, pneumatic testing or alternative leak testing methods defined in the code may be applied; in pneumatic testing, safety regulations such as minimum test pressure depending on the design pressure and pressure relief measures apply. The method and values to be applied must be verified against the relevant clauses of the code.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Standard service: random radiography\/ultrasonics (typically cited as around 5 percent \u2014 exact rate confirmed by code)<\/li>\n\n\n<li>Incremental sampling: inspection expanding to include the same welder&#039;s job in case of failure.<\/li>\n\n\n<li>Pressure test: default hydrostatic; conditional pneumatic or alternative leak test.<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Resource Requirements: WPS, PQR, and Welder Qualifications<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ASME B31.3 requires welding operations to be performed according to a qualified Welding Procedure Specification (WPS) and by qualified welders. The Procedural Qualification Record (PQR) and Welder Performance Qualification (WPQ), upon which the WPS is based, are generally conducted by reference to ASME Section IX. This means that weld quality is based on a separate and established set of rules.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Acceptance criteria (defect limits) for welded fabrication and the qualification of welders and procedures are complementary but separate topics. Weld inspection (WPS and welder qualification) and ISO 5817 weld defect acceptance levels are covered in separate pages on this site; this article only briefly touches upon these topics and does not go into detail.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>WPS and skilled welder requirement (PQR\/WPQ generally referring to ASME Section IX)<\/li>\n\n\n<li>Welder qualifications and WPS are covered on a separate page.<\/li>\n\n\n<li>ISO 5817 welding defect acceptance levels are covered in a separate page.<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Boundary: The Role of AES and the Distinction Between Related Issues<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">AES is not a certification or accredited body; it does not issue ASME code symbols or authorization certificates (e.g., markings like U or PP stamps). Such authorizations are the responsibility of ASME and the authorized bodies. AES&#039;s T\u00dcRKAK accreditation is limited to the 6.1 Electrical Installation area; this text does not imply that process piping certification is offered and is purely for informational purposes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An important distinction in terms of scope clarity: ASME B31.3 is the design and manufacture code for process piping in a new plant and belongs to the American system. Periodic inspection of existing piping in operation is not covered by this code, but rather by API 570 process piping operational inspection, and is discussed on a separate page on this site. EU harmonized piping design falls under EN 13480 and is also covered on a separate page.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In summary: ASME B31.3 = new installation design and manufacturing code (American system); API 570 = periodic inspection of existing piping in operation (separate page); EN 13480 = EU harmonized design (separate page). Which code applies to a specific application must be determined by the plant owner&#039;s requirements and the technical assessment of a qualified engineer.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>AES is not a certification\/approved body; it does not issue ASME code symbols or authorization certificates.<\/li>\n\n\n<li>AES accreditation is limited to 6.1 Electrical Installation only.<\/li>\n\n\n<li>ASME B31.3 = new plant design and manufacture; API 570 = operational inspection (separate page); EN 13480 = EU design (separate page)<\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Related Services<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li><a href=\"https:\/\/aesinn.com\/en\/muayene-periyodik-kontrol\/mekanik-ekipman-muayeneleri\/api-510-570-653-statik-ekipman-muayene-kodlari-basincli-kap-proses-boru-hatti-ve-depolama-tanki\/\">API 510 \/ 570 \/ 653 Static Equipment Inspection Codes (Operational Inspection)<\/a><\/li>\n\n\n<li><a href=\"https:\/\/aesinn.com\/en\/muayene-periyodik-kontrol\/mekanik-ekipman-muayeneleri\/en-13445-ve-en-13480-basincli-kap-ve-endustriyel-boru-icin-avrupa-uyumlastirilmis-tasarim-ve-imalat-standartlari\/\">EN 13445 \/ EN 13480 Pressure Vessels and Industrial Piping (EU Design)<\/a><\/li>\n\n\n<li><a href=\"https:\/\/aesinn.com\/en\/test-ve-olcum-hizmetleri\/kaynak-muayenesi-ve-kaynakci-wps-yeterlilik-degerlendirmesi-aws-d1-1-asme-bpvc-section-ix-ve-ts-en-iso-9606\/\">Welding Inspection and Welder \/ WPS Qualification Assessment<\/a><\/li>\n\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Frequently Asked Questions<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What exactly does ASME B31.3 cover?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">ASME B31.3 specifies the design, materials, manufacture, assembly, inspection, and pressure testing standards for process piping systems in facilities such as refineries, petrochemicals, chemical plants, pharmaceuticals, and food processing plants. Building plumbing, power plant steam headers, and transmission pipelines are excluded.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What is the difference between ASME B31.3 and B31.1?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B31.1 is the power piping code and primarily governs steam and condensate lines in power plants; the main risk is physical explosion. B31.3 is the process piping code; it focuses on corrosive and toxic services in refineries and chemical plants. Transmission pipelines fall under B31.4 and B31.8.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Are Inspector and Examiner the same thing in ASME B31.3?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">No. Examination is the manufacturer&#039;s responsibility and is carried out by the Examiner who performs non-destructive testing. Inspection, on the other hand, is the responsibility of the facility owner and is carried out by the owner&#039;s appointed Inspector to verify code compliance. These two roles are distinct according to the code.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How many radiograms are needed for a standard fluid service?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The code for Standard Fluid Service prescribes radiographic or ultrasonic inspection of butt welds at a random rate; this rate is typically cited in the literature as around 5 percent. The exact rate should be confirmed from the relevant clauses of the code according to the applied code printout and service class. If a weld is unacceptable, the inspection is progressively extended to the work of the same welder.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How is a pressure test performed according to ASME B31.3?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The default method is hydrostatic testing. Under certain conditions, pneumatic testing or alternative leak testing methods defined in the code may be applied. In pneumatic testing, safety regulations such as minimum test pressure and pressure relief measures based on the design pressure apply; values must be verified from the code.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Does AES provide certification under ASME B31.3?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">No. AES is not a certification or accredited body; it does not issue ASME code symbols or authorization certificates; that is the responsibility of ASME and its authorized bodies. AES accreditation is limited to area 6.1 Electrical Installations only, and this content is for informational purposes only.<\/p>","protected":false},"excerpt":{"rendered":"<p>ASME B31.3, rafineri ve petrokimya tesislerindeki proses boru sistemlerinin tasar\u0131m, imalat, muayene ve test esaslar\u0131n\u0131 belirleyen Amerikan kaynakl\u0131 bir koddur. Bu yaz\u0131, kodun kapsam\u0131n\u0131 ve temel kavramlar\u0131n\u0131 bilgilendirme amac\u0131yla a\u00e7\u0131klar.<\/p>","protected":false},"author":1,"featured_media":6219,"parent":2518,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","slim_seo":{"title":"ASME B31.3 Process Tubing: Design and Manufacturing Code","description":"ASME B31.3 process piping code: fluid service classes, inspection and examination distinction, pressure testing. For informational purposes only."},"_pplb_hide_from_list":false,"footnotes":""},"class_list":["post-6216","page","type-page","status-publish","has-post-thumbnail","hentry"],"acf":[],"taxonomy_info":[],"featured_image_src_large":["https:\/\/aesinn.com\/wp-content\/uploads\/asmeb313-aes-kart-1024x1024.png",1024,1024,true],"author_info":{"display_name":"Emre Metin","author_link":"https:\/\/aesinn.com\/en\/author\/yonetim\/"},"comment_info":"","_hostinger_reach_plugin_has_subscription_block":false,"_hostinger_reach_plugin_is_elementor":false,"_links":{"self":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/6216","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/comments?post=6216"}],"version-history":[{"count":2,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/6216\/revisions"}],"predecessor-version":[{"id":6225,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/6216\/revisions\/6225"}],"up":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/pages\/2518"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/media\/6219"}],"wp:attachment":[{"href":"https:\/\/aesinn.com\/en\/wp-json\/wp\/v2\/media?parent=6216"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}