{"id":6159,"date":"2025-12-04T13:41:15","date_gmt":"2025-12-04T05:41:15","guid":{"rendered":"https:\/\/sunhyings.com\/?p=6159"},"modified":"2026-03-13T13:34:41","modified_gmt":"2026-03-13T05:34:41","slug":"asme-b16-5-vs-din-en-1092-1-flange-comparison-guide","status":"publish","type":"post","link":"https:\/\/sunhyings.com\/pt\/blog\/asme-b16-5-vs-din-en-1092-1-flange-comparison-guide\/","title":{"rendered":"Compara\u00e7\u00e3o entre flanges ASME B16.5 e DIN EN 1092-1"},"content":{"rendered":"\n<figure class=\"wp-block-image\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"1024\" src=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-1024x1024.webp\" alt=\"Detailed Comparison: ASME B16.5 vs DIN EN 1092-1 Flange Standards\" class=\"wp-image-6176\" srcset=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-1024x1024.webp 1024w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-800x800.webp 800w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-300x300.webp 300w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-768x768.webp 768w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-1536x1536.webp 1536w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare-12x12.webp 12w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/How-ASME-B16.5-and-DIN-EN-1092-1-Flanges-Compare.webp 2048w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>In industrial piping, mixing <a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/www.asme.org\/codes-standards\/find-codes-standards\/b16-5-pipe-flanges-flanged-fittings-nps-1-2-nps-24-metric-inch-standard\">ASME B16.5<\/a> with <a target=\"_blank\" rel=\"noreferrer noopener nofollow\" href=\"https:\/\/knowledge.bsigroup.com\/products\/flanges-and-their-joints-circular-flanges-for-pipes-valves-fittings-and-accessories-pn-designated-steel-flanges-2\">DIN EN 1092-1<\/a> is not a \u201csmall typo\u201d\u2014it is a bolt-up risk that can stop commissioning.<\/strong> Both standards define flange dimensions, facing, drilling, and pressure-temperature limits, but they follow different engineering systems: <strong>ASME (NPS \/ Class \/ inch-based)<\/strong> vs. <strong>EN (DN \/ PN \/ metric-based)<\/strong>. Choosing correctly protects safety, schedule, and total lifecycle cost.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Procurement reality:<\/strong> \u201cDN100\u201d and \u201c4-inch\u201d are not interchangeable purchase specs unless you also lock the standard + drilling pattern.<\/li>\n\n\n\n<li><strong>Common failure mode:<\/strong> Bolt circle mismatch causes field rework, wrong studs, and repeated gasket damage during attempted assembly.<\/li>\n\n\n\n<li><strong>Best practice:<\/strong> Always specify <em>Standard + Size + Rating + Facing\/Form + Material + Bore<\/em> on the PO and drawing.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/Procurement-Specification-Template.webp\" alt=\"\"\/><\/figure>\n\n\n\n<p>Sunhy manufactures stainless steel flanges to both systems on request. The key is to keep the project specification \u201cunambiguous\u201d so the shop machines the correct <strong>drilling, facing, and thickness<\/strong> for your standard family.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Standard<\/th><th>Core Definition<\/th><\/tr><tr><td><strong>ASME B16.5<\/strong><\/td><td>Pipe flanges and flanged fittings using <strong>NPS<\/strong> sizing, <strong>Class<\/strong> pressure ratings, and defined facings\/drilling (commonly used up to NPS 24).<\/td><\/tr><tr><td><strong>DIN EN 1092-1<\/strong><\/td><td>Circular <strong>steel<\/strong> flanges using <strong>DN<\/strong> sizing and <strong>PN<\/strong> designations, with EN face \u201cForms\u201d and metric drilling (covers a wider DN range than B16.5).<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"ASME B16.5 vs DIN EN 1092-1 Overview\">ASME B16.5 vs DIN EN 1092-1: Detailed Overview<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Key Technical Differences<\/h3>\n\n\n\n<p><strong>The real differences are the rating system, the drilling pattern, and the dimensional \u201cphilosophy.\u201d<\/strong><\/p>\n\n\n\n<p>You will notice that <a href=\"https:\/\/sunhyings.com\/blog\/asme-b16-5-mean-for-pipe-flanges-and-flange-fittings\/\" target=\"_blank\" rel=\"noreferrer noopener\">ASME B16.5<\/a> is typically specified in inches and uses <strong>Class<\/strong> ratings, while EN 1092-1 is specified in millimetres and uses <strong>PN<\/strong> designations. The safest way to compare is to check: <strong>(1) bolt circle, (2) number\/size of bolt holes, (3) facing type, (4) pressure-temperature table for the actual material.<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Aspect<\/th><th>ASME B16.5 (USA)<\/th><th>DIN EN 1092-1 (Europe)<\/th><\/tr><tr><td>Pressure Rating System<\/td><td><strong>Class<\/strong> (e.g., Class 150, 300, 600) with pressure-temperature ratings by material group.<\/td><td><strong>PN<\/strong> (e.g., PN10, PN16, PN40) with limits depending on material and temperature.<\/td><\/tr><tr><td>Size System<\/td><td><strong>NPS<\/strong> (nominal, inch-based naming; dimensions are standardized, not \u201cfree\u201d).<\/td><td><strong>DN<\/strong> (nominal, metric naming; drilling and dimensions standardized by PN series).<\/td><\/tr><tr><td>Flange Face Types<\/td><td>RF (Raised Face), RTJ (Ring Type Joint), FF (Flat Face), plus other ASME facings.<\/td><td>Form A (Flat), Form B (Raised), plus tongue\/groove and male\/female style forms.<\/td><\/tr><tr><td>Drilling \/ Bolt Pattern<\/td><td>ASME bolt circles and bolt holes are defined per NPS + Class. Many sizes use inch-based bolt circles.<\/td><td>EN bolt circles and bolt holes are defined per DN + PN. Metric bolt circles commonly differ from ASME.<\/td><\/tr><tr><td>Material Specification System<\/td><td>ASTM \/ ASME material grades (e.g., A105, A182 F316L).<\/td><td>EN material numbers (e.g., 1.4307, 1.4404) and EN product standards.<\/td><\/tr><tr><td>Interchangeability<\/td><td><strong>Not directly interchangeable<\/strong> with EN drilling\/facing in most cases; adapters may be required.<\/td><td>Interchangeable within EN\/DIN flange families when the same DN\/PN and form are specified.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pressure ratings are not \u201csimple conversions\u201d:<\/strong> Class and PN may look similar at room temperature, but both standards require pressure-temperature checks for the actual material.<\/li>\n\n\n\n<li><strong>Threads are different:<\/strong> EN threaded flanges commonly use ISO metric threads, while many ASME threaded systems use NPT conventions.<\/li>\n\n\n\n<li><strong>Fastener planning changes:<\/strong> bolt quantity, bolt diameter, and stud length choices change with drilling patterns and facing heights.<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Expert Tip:<\/strong><br>Never order \u201c4-inch flanges\u201d without adding the standard and rating. Write it like: \u201cASME B16.5 NPS 4 Class 150 RF\u201d or \u201cEN 1092-1 DN100 PN16 Form B1\u201d. This one line prevents most cross-standard bolt-up failures.<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\">Main Similarities<\/h3>\n\n\n\n<p><strong>Despite dimensional differences, both standards aim for safe, repeatable, leak-tight joints.<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Common flange types exist in both systems:<\/strong> Weld neck, slip-on\/plate style, blind, threaded, lap joint\/loose styles.<\/li>\n\n\n\n<li><strong>Both require pressure-temperature discipline:<\/strong> rating depends on material and operating temperature, not \u201cnameplate only.\u201d<\/li>\n\n\n\n<li><strong>Traceability mindset:<\/strong> projects typically expect heat numbers, MTC\/MTR documentation, and dimensional inspection records.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"What is ASME B16.5?\">Deep Dive: ASME B16.5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Scope and Use<\/h3>\n\n\n\n<p><strong>ASME B16.5 is widely used in North American process industries and many global EPC specifications.<\/strong> It standardises dimensions, tolerances, facings, drilling, and pressure-temperature ratings by material group. For larger sizes above the B16.5 range, projects typically move to <a href=\"https:\/\/www.asme.org\/codes-standards\/find-codes-standards\/b16-47-large-diameter-steel-flanges-nps-26-nps-60-metric-inch-standard\" target=\"_blank\" rel=\"noreferrer noopener\">ASME B16.47<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a href=\"https:\/\/sunhyings.com\/stainless-steel-flange\/standards\/asme-b16-5\/\">ASME B16.5 Flange Types<\/a><\/h3>\n\n\n\n<p><strong>ASME defines flanges primarily by how they connect to pipe and how they manage stress.<\/strong> Here is the full breakdown of common types you will encounter:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Flange Type<\/th><th>Description &amp; Best Use<\/th><\/tr><tr><td><strong>Welding Neck (WN)<\/strong><\/td><td>Butt-welded hub flange; preferred for high-pressure\/high-temperature and cyclic loading.<\/td><\/tr><tr><td><strong>Slip On (SO)<\/strong><\/td><td>Easy alignment, welded fillets; common in utilities where fatigue is not critical.<\/td><\/tr><tr><td><strong>Blind (BL)<\/strong><\/td><td>Closes a line or nozzle; useful for pressure testing and future expansion.<\/td><\/tr><tr><td><strong>Threaded (THD)<\/strong><\/td><td>Easy alignment, welded fillets are common in utilities where fatigue is not critical.<\/td><\/tr><tr><td><strong>Socket Welding (SW)<\/strong><\/td><td>Small-bore, high-pressure services; sensitive to fit-up and weld quality.<\/td><\/tr><tr><td><strong>Lap Joint (LJ)<\/strong><\/td><td>Used with stub ends; allows rotation for easier bolt alignment and frequent dismantling.<\/td><\/tr><tr><td><strong>Long Weld Neck (LWN)<\/strong><\/td><td>Used when welding is restricted; thread standard must be specified to avoid a mismatch.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Note:<\/strong><br>Assembly quality matters as much as flange type. Many projects reference bolted-joint assembly guidance (torque, tightening pattern, gasket handling) such as ASME PCC-1.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"What is DIN EN 1092-1?\">Deep Dive: DIN EN 1092-1<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Scope and Use<\/h3>\n\n\n\n<p><strong>DIN EN 1092-1 is the European flange standard for circular <em>steel<\/em> flanges.<\/strong> It is built around DN (nominal diameter) and PN (pressure designation) with metric drilling and EN face forms. In EU projects, flange choice is often tied to regulatory compliance, such as the <strong>Pressure Equipment Directive (PED)<\/strong> and the project\u2019s harmonised standards list.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a href=\"https:\/\/sunhyings.com\/stainless-steel-flange\/standards\/en-din\/\">DIN EN 1092-1 Flange Types<\/a> (The \u201cType\u201d System)<\/h3>\n\n\n\n<p><strong>EN uses a numerical \u201cType\u201d system rather than English names.<\/strong> This reduces language ambiguity across suppliers. Common types include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Type 01:<\/strong> Plate flange for welding (flat\/plate style).<\/li>\n\n\n\n<li><strong>Type 02:<\/strong> Loose plate flange with weld-on collar.<\/li>\n\n\n\n<li><strong>Type 04:<\/strong> Loose plate flange with weld-neck collar.<\/li>\n\n\n\n<li><strong>Type 05:<\/strong> Blind flange.<\/li>\n\n\n\n<li><strong>Type 11:<\/strong> Welding neck flange (process piping workhorse).<\/li>\n\n\n\n<li><strong>Type 12:<\/strong> Hubbed slip-on flange for welding.<\/li>\n\n\n\n<li><strong>Type 13:<\/strong> Threaded hub flange (thread standard must be specified).<\/li>\n\n\n\n<li><strong>Type 21:<\/strong> Integral flange (application-specific).<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>EN Type<\/th><th>ASME Equivalent (Functional)<\/th><th>Key Reminder<\/th><\/tr><tr><td>Type 01<\/td><td>Plate \/ slip-on family<\/td><td>Function may match, but drilling and thickness usually differ by standard.<\/td><\/tr><tr><td>Type 05<\/td><td>Blind Flange<\/td><td>Same function; dimensions\/bolt pattern differ.<\/td><\/tr><tr><td>Type 11<\/td><td>Weld Neck<\/td><td>Do not assume \u201cDN100 = NPS 4\u201d bolt-up; verify bolt circle and bore.<\/td><\/tr><tr><td>Type 13<\/td><td>Threaded<\/td><td>Metric vs NPT conventions can cause fit failures if unspecified.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Pressure Ratings in ASME B16.5 and EN 1092-1\">Pressure Ratings: Class vs. PN<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">ASME B16.5 Pressure Classes (Temperature Dependent)<\/h3>\n\n\n\n<p><a target=\"_blank\" href=\"https:\/\/sunhyings.com\/blog\/class-150-vs-class-300-flange-pressure-ratings-comparison\/\" rel=\"noreferrer noopener\"><strong>ASME uses \u201cClasses\u201d<\/strong><\/a><strong>, and the allowable pressure drops as temperature rises.<\/strong> Below is a commonly referenced pressure-temperature example table for carbon steel (illustrative values):<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Pressure Class<\/th><th>Ambient (100\u00b0F \/ 38\u00b0C)<\/th><th>400\u00b0F (200\u00b0C)<\/th><th>600\u00b0F (315\u00b0C)<\/th><th>800\u00b0F (425\u00b0C)<\/th><\/tr><tr><td><strong>Class 150<\/strong><\/td><td><a target=\"_blank\" rel=\"noreferrer noopener nofollow\" href=\"https:\/\/www.wermac.org\/flanges\/flanges_pressure-temperature-ratings_astm_asme.html\">285 psig<\/a><\/td><td>200 psig<\/td><td>140 psig<\/td><td>80 psig<\/td><\/tr><tr><td><strong>Class 300<\/strong><\/td><td>740 psig<\/td><td>635 psig<\/td><td>550 psig<\/td><td>410 psig<\/td><\/tr><tr><td><strong>Class 400<\/strong><\/td><td>990 psig<\/td><td>845 psig<\/td><td>730 psig<\/td><td>550 psig<\/td><\/tr><tr><td><strong>Class 600<\/strong><\/td><td>1480 psig<\/td><td>1270 psig<\/td><td>1095 psig<\/td><td>825 psig<\/td><\/tr><tr><td><strong>Class 900<\/strong><\/td><td>2220 psig<\/td><td>1900 psig<\/td><td>1640 psig<\/td><td>1235 psig<\/td><\/tr><tr><td><strong>Class 1500<\/strong><\/td><td>3705 psig<\/td><td>3170 psig<\/td><td>2735 psig<\/td><td>2055 psig<\/td><\/tr><tr><td><strong>Class 2500<\/strong><\/td><td>6170 psig<\/td><td>5280 psig<\/td><td>4560 psig<\/td><td>3430 psig<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Expert Note:<\/strong><br>Temperature is a \u201csilent derating factor.\u201d If you compare Class vs PN, compare them at the <em>same operating temperature<\/em> and for the <em>same material group<\/em>.<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\">EN 1092-1 PN Ratings<\/h3>\n\n\n\n<p><strong>EN 1092-1 uses PN (Pressure Nominal) as a designation system, not a universal \u201cguaranteed working pressure\u201d for all temperatures.<\/strong> The allowable pressure depends on flange material and operating temperature, so you must verify against the EN pressure-temperature tables for the selected steel grade.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>PN Rating<\/th><th>Reference Pressure at 20\u00b0C (Bar)<\/th><th>Equivalent PSI (Approx)<\/th><\/tr><tr><td>PN 2.5<\/td><td>2.5<\/td><td>36 psi<\/td><\/tr><tr><td>PN 6<\/td><td>6<\/td><td>87 psi<\/td><\/tr><tr><td>PN 10<\/td><td>10<\/td><td>145 psi<\/td><\/tr><tr><td>PN 16<\/td><td>16<\/td><td>232 psi<\/td><\/tr><tr><td>PN 25<\/td><td>25<\/td><td>362 psi<\/td><\/tr><tr><td>PN 40<\/td><td>40<\/td><td>580 psi<\/td><\/tr><tr><td>PN 63<\/td><td>63<\/td><td>913 psi<\/td><\/tr><tr><td>PN 100<\/td><td>100<\/td><td>1450 psi<\/td><\/tr><tr><td>PN 160<\/td><td>160<\/td><td>2320 psi<\/td><\/tr><tr><td>PN 250<\/td><td>250<\/td><td>3625 psi<\/td><\/tr><tr><td>PN 400<\/td><td>400<\/td><td>5800 psi<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/chart_1764826181445196163.webp\" alt=\"Bar chart showing EN 1092-1 flange PN ratings and their maximum applicable pressures\" class=\"wp-image-6160\" srcset=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/chart_1764826181445196163.webp 1024w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/chart_1764826181445196163-800x600.webp 800w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/chart_1764826181445196163-768x576.webp 768w, https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/chart_1764826181445196163-16x12.webp 16w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>Practical Comparison (Rule-of-Thumb Only):<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PN 16 is often compared to Class 150 at ambient conditions (verify at temperature).<\/li>\n\n\n\n<li>PN 40 is often compared to Class 300 at ambient conditions (verify at temperature).<\/li>\n\n\n\n<li>PN 100 is often compared to Class 600 at ambient conditions (verify at temperature).<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Flange Face Types and Sealing\">Flange Face Types and Sealing<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">ASME B16.5 Face Types<\/h3>\n\n\n\n<p><strong>The face type dictates the gasket style, seating stress, and assembly sensitivity.<\/strong> Common face types include:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th><a target=\"_blank\" rel=\"noreferrer noopener nofollow\" href=\"https:\/\/www.wermac.org\/flanges\/flanges_raised-face_flat-face_ring-type-joint.html\">Face Type<\/a><\/th><th>Sealing Principle<\/th><th>Advantages<\/th><th>Limitations<\/th><th>Applications<\/th><\/tr><tr><td><strong>RF (Raised Face)<\/strong><\/td><td>Concentrates bolt force on a smaller gasket area.<\/td><td>Widely available gaskets; easy sourcing.<\/td><td>More sensitive to surface finish and bolt load control.<\/td><td>Oil, gas, chemical, utilities (typical Class 150\u2013600).<\/td><\/tr><tr><td><strong>RTJ (Ring Type Joint)<\/strong><\/td><td>Metal ring seats into a machined groove (metal-to-metal).<\/td><td>Handles very high pressure\/vibration when assembled correctly.<\/td><td>Higher machining cost; requires controlled tightening; the ring is often single-use.<\/td><td>High-pressure offshore, steam, critical services.<\/td><\/tr><tr><td><strong>FF (Flat Face)<\/strong><\/td><td>Higher machining cost; requires controlled tightening; ring is often single-use.<\/td><td>Helps protect brittle mating flanges (e.g., cast iron).<\/td><td>Lower sealing stress; not for high-pressure services.<\/td><td>Water treatment, cast iron equipment, FRP systems.<\/td><\/tr><tr><td><strong>TG (Tongue and Groove)<\/strong><\/td><td>Enclosed gasket; tongue locates into the groove.<\/td><td>Good alignment; gasket protected from blowout\/erosion.<\/td><td>Requires matched pairs; tighter machining control.<\/td><td>Toxic\/flammable media, special services.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/Facing-Selection-Guide.webp\" alt=\"\"\/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">EN 1092-1 Face Types<\/h3>\n\n\n\n<p><strong>EN uses a \u201cForm\u201d system for faces:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Form A:<\/strong> Flat Face (comparable to ASME FF).<\/li>\n\n\n\n<li><strong>Form B:<\/strong> Raised Face (comparable to ASME RF). Note: Form B1 vs B2 may differ by finish\/requirements depending on project spec.<\/li>\n\n\n\n<li><strong>Form C\/D:<\/strong> Tongue and Groove.<\/li>\n\n\n\n<li><strong>Form E\/F:<\/strong> Spigot and Recess (Male\/Female style).<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Dimensions and Tolerances in Flanges\">Dimensions and Tolerances<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">B16.5 Dimensional Standards (Imperial)<\/h3>\n\n\n\n<p><strong>ASME B16.5<\/strong> covers standard flange dimensions for many projects. For larger diameters, engineering specs typically reference <strong>ASME B16.47<\/strong> instead of \u201cguessing\u201d a B16.5 pattern.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>NPS (Nominal Pipe Size):<\/strong> A standardised naming system\u2014do not treat it as a measured OD.<\/li>\n\n\n\n<li><strong>Bolt circle &amp; holes:<\/strong> Defined by NPS + Class; do not assume EN drilling will match.<\/li>\n\n\n\n<li><strong>Field lesson:<\/strong> if bolt circle differs, assembly fails even when \u201cDN and NPS look equivalent.\u201d<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">EN 1092-1 Dimensions (Metric)<\/h3>\n\n\n\n<p><strong>EN 1092-1<\/strong> is based on the DN and PN series with metric drilling. It is common in EU industrial plants, water, marine, and many international EPC packages that adopt EN standards.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Feature<\/th><th>ASME B16.5<\/th><th>EN Flange<\/th><\/tr><tr><td>Nominal Diameter<\/td><td>NPS \u00bd \u2013 NPS 24<\/td><td>DN 10 \u2013 DN 2000+ (project dependent)<\/td><\/tr><tr><td>Pressure Rating<\/td><td>Class 150 \u2013 Class 2500<\/td><td>PN 2.5 \u2013 PN 400<\/td><\/tr><tr><td>Units<\/td><td>Inches<\/td><td>Millimeters<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2025\/12\/Bolt-Circle-Mismatch-Diagram.webp\" alt=\"\"\/><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Critical Warning:<\/strong><br>Mixing ASME and EN flanges often leads to bolt circle misalignment. Example: DN100 PN16 commonly uses a 180 mm bolt circle, while NPS 4 Class 150 commonly uses a 190.5 mm bolt circle. They will not bolt up without an adapter or redesign.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"Material Specifications\">Material Specifications<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">ASME B16.5 Materials<\/h3>\n\n\n\n<p>ASME projects commonly specify ASTM\/ASME forging grades and require MTC\/MTR traceability for audits and turnaround work.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Forgings:<\/strong> ASTM A105 (carbon steel), ASTM A182 F304L\/F316L (stainless steel).<\/li>\n\n\n\n<li><strong>Engineering reminder:<\/strong> \u201cSimilar performance\u201d is not the same as \u201cequivalent chemistry.\u201d Match the project material spec and verify by MTC and PMI where required.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">EN 1092-1 Materials<\/h3>\n\n\n\n<p>EN projects commonly specify EN material numbers and require documentation aligned to PED where applicable.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Material<\/th><th>ASME Standard (Common)<\/th><th>EN Equivalent (Common Reference)<\/th><\/tr><tr><td>Carbon Steel<\/td><td>ASTM A105<\/td><td>P245GH (1.0352) (verify by project spec)<\/td><\/tr><tr><td>Stainless 304L<\/td><td>ASTM A182 F304L<\/td><td>1.4307<\/td><\/tr><tr><td>Stainless 316L<\/td><td>ASTM A182 F316L<\/td><td>1.4404<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>Sunhy supports full traceability (heat number linkage) and can provide PMI\/spectrometer verification when the project QA plan calls for it. For buyers, the fastest risk-reducer is to request the MTC format you need before mass production.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"How to Choose the Right Flange Standard\">Selection Guide: Which One Do I Need?<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Decision Matrix<\/h3>\n\n\n\n<p><strong>Use this guide to select the correct standard family for your project\u2014then lock the full callout on the PO.<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Scenario<\/th><th>Go with ASME B16.5<\/th><th>Go with DIN EN 1092-1<\/th><\/tr><tr><td><strong>Region \/ Spec Owner<\/strong><\/td><td>North America EPC specs, many oil &amp; gas\/process specs using ASME families<\/td><td>EU-based plants, EN standard packages, many water\/marine and PED-driven projects<\/td><\/tr><tr><td><strong>Rating System<\/strong><\/td><td>Class-based pressure-temperature checks by ASME material groups<\/td><td>PN designation with EN pressure-temperature checks by EN steel grade<\/td><\/tr><tr><td><strong>Supplier \/ QA<\/strong><\/td><td>ASTM\/ASME MTC + dimensional inspection to ASME drilling\/facing<\/td><td>EN material numbers + PED\/EN documentation when required<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Regional and Compliance Factors<\/h3>\n\n\n\n<p>Compliance often drives the final decision more than \u201cpreference.\u201d If the equipment is placed on the EU market, PED obligations may apply depending on fluid group, pressure, and volume.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ASME route:<\/strong> Often selected when the piping class and project standard are written around ASME B16 \/ ASTM grades.<\/li>\n\n\n\n<li><strong>EN route:<\/strong> Common when the project documentation package is built around EN standards and PED compliance expectations.<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Expert Advice:<\/strong><br>Don\u2019t guess. Check the P&amp;ID and the piping class\/spec sheet. The standard family (ASME vs EN) and the facing\/drilling will be defined there.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"FAQ\">FAQ<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What is the main difference between ASME B16.5 and DIN EN 1092-1 flanges?<\/h3>\n\n\n\n<p><strong>ASME B16.5 uses NPS + Class (inch-based naming), while DIN EN 1092-1 uses DN + PN (metric naming). Their drilling and dimensions are often different, so they are generally not bolt-up compatible.<\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Can you use ASME and EN flanges together?<\/h3>\n\n\n\n<p><strong>Usually no.<\/strong> Even if the \u201cpressure level\u201d seems similar, bolt circle diameter, hole count, and facing form often differ. If you must connect systems, you typically need an <strong>adapter flange<\/strong> or a designed transition spool.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What happens above 24 inches for ASME flanges?<\/h3>\n\n\n\n<p><strong>Many projects use ASME B16.5 patterns up to NPS 24.<\/strong> For larger sizes, specifications typically switch to <strong>ASME B16.47<\/strong> (large diameter steel flanges) rather than forcing non-standard drilling.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What is the difference between ASME B16.47 Series A and Series B?<\/h3>\n\n\n\n<p><strong>Series A is generally heavier and follows a different drilling philosophy, while Series B is generally lighter.<\/strong> They are not interchangeable unless the project specifically designs them to match.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Why does material traceability matter for flanges?<\/h3>\n\n\n\n<p><a href=\"https:\/\/sunhyings.com\/blog\/how-to-interpret-a-flange-material-certificate\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Material <\/strong><\/a><a href=\"https:\/\/sunhyings.com\/blog\/how-to-interpret-a-flange-material-certificate\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>traceability&nbsp;<\/strong><\/a>links the<strong> flange to the heat number and MTC requirements, supporting safety audits and ensuring it meets the chemical and mechanical requirements of the specified ASME or EN grade.<\/strong><\/p>\n\n\n\n<script type=\"application\/ld+json\">{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the main difference between ASME B16.5 and DIN EN 1092-1 flanges?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"ASME B16.5 uses NPS sizing and Class ratings with inch-based drilling and ASME facing conventions. DIN EN 1092-1 uses DN sizing and PN designations with metric drilling and EN face forms. The bolt pattern and dimensions often differ, so they are generally not bolt-up compatible.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can you use ASME and EN flanges together?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Usually no. Even when pressure levels appear similar, bolt circle diameter, hole count, and facing form often differ. If a connection is required, use an engineered adapter flange or a designed transition spool.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What happens above 24 inches for ASME flanges?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Many projects use ASME B16.5 patterns up to NPS 24. For larger sizes, specifications typically switch to ASME B16.47 (large diameter steel flanges) rather than forcing non-standard drilling.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between ASME B16.47 Series A and Series B?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Series A is generally heavier and follows a different drilling philosophy, while Series B is generally lighter. They are not interchangeable unless the project specifically designs them to match.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why does material traceability matter for flanges?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Traceability links each flange to its heat number and material test certificate (MTC\/MTR), supporting safety audits and confirming the flange meets the chemical and mechanical requirements of the specified ASME or EN grade.\"\n      }\n    }\n  ]\n}\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>In industrial piping, mixing ASME B16.5 with DIN EN 1092-1 is not a \u201csmall typo\u201d\u2014it is a bolt-up risk that can stop commissioning. Both standards define flange dimensions, facing, drilling, and pressure-temperature limits, but they follow different engineering systems: ASME (NPS \/ Class \/ inch-based) vs. EN (DN \/ PN \/ metric-based). Choosing correctly protects [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6178,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[41,69,71,113,114],"class_list":["post-6159","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-selection-comparison","tag-pf-flanges","tag-std-asme-b16-5","tag-std-din-en-1092-1","tag-topic-comparison","tag-topic-selection"],"_links":{"self":[{"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/posts\/6159","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/comments?post=6159"}],"version-history":[{"count":7,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/posts\/6159\/revisions"}],"predecessor-version":[{"id":13126,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/posts\/6159\/revisions\/13126"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/media\/6178"}],"wp:attachment":[{"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/media?parent=6159"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/categories?post=6159"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sunhyings.com\/pt\/wp-json\/wp\/v2\/tags?post=6159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}