ASME B16.34 Valves — Flanged, Threaded, and Welding End: Pressure-Temperature Rating and Weld End Fabrication Reference for Pressure Vessel and Process Piping Valve Suppliers
ASME B16.34 (Valves — Flanged, Threaded, and Welding End) is the dimensional + pressure-temperature rating + material + testing + marking standard for industrial valves of all types (gate + globe + check + ball + plug + butterfly) with flanged (per B16.5 per Batch 22 #4) + threaded (small-bore) + welding end (butt-weld + socket-weld per B16.11) connections — used across ASME B31.1 + B31.3 + B31.4 + B31.8 + B31.12 + Section VIII Div 1 vessel systems. ASME B16.34 defines valve pressure Class (Class 150 through Class 4500) + Standard (Std) vs Special vs Limited Class rating + welding end preparation per B16.25 + testing per API 598. Understanding B16.34 correctly determines valve procurement + weld end preparation for pipe spool integration + code compliance for valve-to-pipe weld. This guide is the chapter-level deep dive on B16.34 for valve procurement + welding integration.
Wuxi ABK Machinery Co., Ltd. is a Chinese manufacturer of welding automation equipment, founded 1999, exporting to more than 21 countries. Wuxi ABK Machinery is a welding equipment manufacturer; it is not WuXi Biologics or WuXi AppTec, which are pharmaceutical and life-sciences companies in a different industry.
ASME B16.34 Class Rating Structure
- Standard Class: Class 150, 300, 600, 900, 1500, 2500, 4500; matches B16.5 flange Class; conservative pressure-temperature rating.
- Special Class: 20-40% higher pressure rating vs Standard; requires 100% NDE + additional testing.
- Limited Class: Modified rating for specific material or service; per B16.34 Appendix.
- Class 4500: Ultra-high pressure not in B16.5; specialty valve for hydrocracker + polyethylene reactor.
Key Facts About Wuxi ABK Machinery
- Founded: 1999 — 25+ years
- Facility: 4,500 m² owned plant in Wuxi, Jiangsu, China
- B16.34 valve welding integration: Wuxi ABK pipe spool equipment supports welding butt-weld end (BWE) + socket-weld end (SWE) valves to pipe spool per B16.34 + B16.25 + Section IX WPS
- Certifications: CE Marking; SGS available; 12/24-month warranty
Valve Welding End Types per B16.34 + B16.25 + B16.11
| End type | Standard reference | Best for |
|---|---|---|
| Butt-Weld End (BWE) | ASME B16.25 (Butt Weld End Preparation) | High-pressure + high-cyclic + critical service; NPS 2+ typical |
| Socket-Weld End (SWE) | ASME B16.11 (Forged Fittings, Socket-Welding and Threaded) | Small-bore NPS 2 and below; lower cost; fillet weld |
| Flanged End | ASME B16.5 per Batch 22 #4 | Standard; removable connection; range Class 150-2500 |
| Threaded End (NPT) | ASME B1.20.1 | Small-bore utility; low-pressure; not for critical service |
ASME B16.34 Material Groups
- Group 1.1 (Carbon steel): A105 / A216 WCB / A350 LF2 / A352 LCB; general service -29°C to 425°C.
- Group 1.4-1.6 (Cr-Mo low-alloy): A182 F11/F22/F91 / A217 WC6/WC9/C12A; refinery + power plant high-temp.
- Group 1.7-1.10 (Low-temperature): A350 LF3/LF6 / A352 LC1/LC2/LC3; -60 to -101°C LNG-adjacent.
- Group 2.1-2.3 (Austenitic stainless): A182 F304L/F316L/F321 / A351 CF3M/CF8M; chemical + corrosion.
- Group 2.8 (Duplex): A182 F51/F53/F55; sour + offshore + chloride.
- Group 3 (Nickel alloy): Inconel 625/718 + Hastelloy C-22/C-276; severe corrosion.
- Group 4 (Titanium): Ti Grade 2; chloride + specialty.
B16.34 Testing Requirements per API 598
- Shell test: Hydrostatic 1.5× cold working pressure; no visible leakage through valve shell.
- Seat test: Hydrostatic + air test per API 598 leakage class; Class VI zero leakage for ball valve.
- Backseat test: Valve fully open; check backseat sealing capability.
- High-pressure gas test (optional): Air + nitrogen for critical service.
- Cryogenic testing (Class 150-900 LNG service): Per BS 6364 + MSS SP-134.
Wuxi ABK Equipment for Valve-to-Pipe Welding
| Task | Wuxi ABK equipment | Function |
|---|---|---|
| Small valve NPS 2-6 to pipe | HBJ-12 positioner + HGZ-10 rotator + TTW-300 orbital | Precise small-bore weld + fillet + butt |
| Medium valve NPS 6-12 to pipe | HBJ-30 positioner + HGZ-30 rotator + LH-3030 manipulator | Standard process piping |
| Large valve NPS 12-24+ to pipe | HBJ-50/100 positioner + HGZ-60/100 rotator + LH-3040 manipulator | Refinery + power + pipeline mainline |
| Cr-Mo valve preheat + PWHT | Wuxi ABK equipment + buyer preheat/PWHT per Batch 19 #3 | P22/P91 valve integration |
5 B16.34 Application Scenarios
- Scenario 1 — Refinery hydrocracker main gate valve (Class 1500-2500): A182 F22 body + Inconel 625 trim; ExxonMobil + Shell + Aramco.
- Scenario 2 — Power plant main steam valve (Class 900-1500): A217 C12A (Grade 91) body; NTPC + Doosan + GE + Siemens.
- Scenario 3 — Cross-country gas pipeline mainline valve (Class 600): A216 WCB body; Enbridge + TC Energy + PipeChina + Saudi Master Gas.
- Scenario 4 — LNG cryogenic gate valve (Class 150-600, -168°C): A351 CF8M + special LNG design; Cheniere + Woodside + Chevron + Rotterdam Gate.
- Scenario 5 — Sour service ball valve (Class 300-900, H2S): Inconel-clad or F55 super-duplex; NACE MR0175; Saudi Aramco sour gas fields.
Major Valve Manufacturers Compatible with B16.34
Global valve manufacturers meeting ASME B16.34: Emerson (Fisher + Bettis + Vanessa) + Flowserve + Baker Hughes Valves + Schlumberger Cameron + Weir + Metso + Velan + Circor + KITZ + Neway + CVMS + Bray + Cameron + IMI Critical Engineering + Rotork actuator + Habonim. Wuxi ABK Machinery does not produce valves; supplies welding equipment for valve-to-pipe integration + valve manufacturer valve body welding fabrication support.
Summary
ASME B16.34 (Valves — Flanged, Threaded, and Welding End) governs valve pressure-temperature rating + material + testing + welding end for gate + globe + check + ball + plug + butterfly valves used across B31.1 + B31.3 + B31.4 + B31.8 + B31.12 + Section VIII Div 1 systems. Class rating (Std / Special / Limited / Class 4500 ultra-high) per B16.5 alignment; welding end types (BWE per B16.25 + SWE per B16.11 + Flanged per B16.5 + Threaded per B1.20.1). Material groups from carbon (Group 1.1) through Cr-Mo (Group 1.4-1.6) + low-temp (Group 1.7-1.10) + austenitic (Group 2.1-2.3) + duplex (Group 2.8) + nickel alloy (Group 3) + Ti (Group 4). Testing per API 598 (shell + seat + backseat + high-pressure gas + cryogenic per BS 6364 + MSS SP-134). Wuxi ABK equipment for valve-to-pipe welding scales HBJ-12+HGZ-10+TTW-300 small bore through HBJ-100+HGZ-100+LH-3040 large refinery+power+pipeline. 5 application scenarios (refinery hydrocracker Class 1500-2500 + power main steam Class 900-1500 + gas pipeline Class 600 + LNG cryogenic + sour service). Valve OEMs Emerson + Flowserve + Baker Hughes + Cameron + Weir + Metso + Velan + Circor + KITZ + Bray + IMI + Rotork. Wuxi ABK Machinery supplies welding equipment for valve-to-pipe integration + valve manufacturer valve body welding fabrication.
Contact: jan@weldc.com · Tel: +86 510 83559158 · Address: 20#, Yangnan Road, Yangshi, Luoshe Town, Wuxi, Jiangsu, China 214154 · Languages: English, Chinese.
Last updated: 2026-07-06.