North American buyers buy fittings by standard. A purchase order that says "1/2 in 3000# SW tee, A182 F316L, B16.11" defines dimensions, pressure class, material and marking in a single line. Suppliers in Vietnam, China and Southeast Asia that understand these codes get fewer rejected shipments and faster approvals.
Dimensional standards (the "B16" family)
| Standard | Covers |
|---|---|
| ASME B16.9 | Factory-made wrought butt-weld fittings: elbows, tees, reducers, caps, stub ends |
| ASME B16.11 | Forged socket-weld and threaded fittings — Class 2000/3000/6000 threaded, 3000/6000/9000 socket-weld |
| MSS SP-114 | Corrosion-resistant cast threaded and socket-weld fittings, Class 150 and 1000 |
| ASME B16.3 | Malleable iron threaded fittings, Class 150 and 300 |
| ASME B16.5 | Pipe flanges and flanged fittings |
| ASME B16.22 / B16.18 / B16.29 | Wrought copper, cast copper-alloy and wrought DWV solder fittings |
| ASME B1.20.1 | NPT pipe threads — the North American taper thread, not BSP |
Material specifications (ASTM)
- A105 — forged carbon steel. A182 — forged alloy and stainless (F304/L, F316/L).
- A234 WPB — carbon steel butt-weld. A403 — stainless butt-weld: WP-S seamless, WP-W welded, WP-WX welded and radiographed.
- A351 CF8 / CF8M — cast stainless (the cast equivalents of 304 and 316).
- Dual certification (for example 304/304L) is common and expected by many distributors.
Marking and traceability
US buyers expect each fitting to be marked with the manufacturer's mark, size, class or schedule, material grade and a heat code that links it to its mill test report (MTR, typically EN 10204 type 3.1). MSS SP-25 sets the common marking rules. Steel fittings must also carry a permanent country-of-origin mark — see origin marking.
Approvals that depend on the application
- Potable water: NSF/ANSI/CAN 61 and lead-free certification to NSF/ANSI 372 — see copper, brass and lead-free.
- Fire protection: UL listing and FM approval for grooved and sprinkler fittings — see grooved and press fittings.
- Canada: a CRN for pressure fittings — see fittings to Canada.
Supplier checklist before the first DDP order
- Send sample fittings with MTRs and a dimensional report for buyer approval — see shipping samples.
- Confirm the thread standard (NPT) and gauge the threads.
- Agree how MTRs are delivered: in each carton, by email or on a portal.
- Keep heat-to-order traceability — US customs and buyers may ask for it.
Trade-remedy orders, Section 232 annexes and Canadian surtaxes on steel and copper products change often, and scope depends on the exact product. This article is general guidance, not legal advice — confirm the treatment of your HTS code and origin before quoting.
Balance Trans ships pipe fittings from Vietnam and Cambodia to the USA and Canada on DDP terms — freight, customs entry, duties and delivery to your warehouse or job site. Fittings made elsewhere in Asia? Ask us what we can arrange; origin is always declared as it truly is. See DDP to the USA & Canada or send your item list for a quote.