SS 316 Pipe Fittings
Giriraj Impex is a manufacturer, stockist, supplier and exporter of SS 316 pipe fittings and SS 316L pipe fittings – butt-weld fittings to ASTM A403 / ASME SA403 grades WP316 and WP316L, dual certified where required, to ASME B16.9 and MSS SP-43, and forged socket weld and threaded fittings in ASTM A182 F316/F316L to ASME B16.11. We manufacture SS 316 fittings in seamless and welded construction from ½" to 24" NB and larger, with mill test certificates.
SS 316 pipe fittings are used in chemical, pharmaceutical, food, marine and coastal piping where the molybdenum in 316 gives better resistance than 304 to chlorides and acids.
Specifications
| Item | Details |
|---|---|
| Butt-weld fittings | ASTM A403 / ASME SA403 WP316, WP316L, dual certified; Class WP-S (seamless), WP-W and WP-WX (welded) |
| Forged fittings | ASTM A182 / ASME SA182 F316, F316L |
| Dimensions | ASME B16.9, MSS SP-43 (butt weld); ASME B16.11, MSS SP-97 (forged); ASME B16.28 short-radius elbows |
| Sizes | Butt weld ½" to 24" NB and larger welded; forged ¼" to 4" NB |
| Wall / class | Sch 5S, 10S, 40S, 80S, 160, XXS; forged Class 2000, 3000, 6000, 9000 |
| Types | 45°, 90° and 180° elbows (long and short radius), equal and reducing tees, concentric and eccentric reducers, caps, stub ends, crosses; socket weld and threaded elbows, tees, couplings, unions, plugs, bushings; olets |
| Finish | Solution annealed and pickled; polished for hygienic service on request |
| Documents | Mill test certificate (MTC); third-party inspection on request |
Chemical composition and mechanical properties
A403 fittings are made from pipe, plate or forgings of the same grade, and meet the chemistry of the starting material. The A312 limits below are typical.
| Grade | UNS | C | Mn | P | S | Si | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|---|
| TP304 | S30400 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0–20.0 | 8.0–11.0 | – |
| TP304L | S30403 | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0–20.0 | 8.0–13.0 | – |
| TP316 | S31600 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 |
| TP316L | S31603 | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 |
Other elements and footnotes as given in the standard. Dual-certified material meets both grades.
| Grade | Tensile strength, MPa (ksi) | Yield strength 0.2%, MPa (ksi) |
|---|---|---|
| WP316 | 515 (75) | 205 (30) |
| WP316L | 485 (70) | 170 (25) |
Background and equivalents are on the SS 316 / 316L page.
WP-S, WP-W and WP-WX
ASTM A403 divides fittings into classes by construction: WP-S fittings are made from seamless pipe or forgings; WP-W are welded fittings where only welds made by the fitting maker are radiographed; and WP-WX are welded fittings with all welds radiographed, including those in the starting pipe. Project specifications for critical service often call for WP-S or WP-WX. Large-diameter fittings are normally welded from plate.
How we manufacture SS 316 fittings
Elbows are formed by hot or cold mandrel bending of pipe, tees by hydraulic bulging or extrusion, and reducers by pressing; larger fittings are formed from plate and welded. After forming, every fitting is solution annealed and quenched to restore corrosion resistance, pickled and passivated, machined to bevel ends to ASME B16.25 and inspected for dimensions to ASME B16.9. Forged fittings are machined from A182 forgings to ASME B16.11. Each fitting is marked with grade, class, size, schedule and heat number.
Choosing 316 or 316L fittings
For welded piping, WP316L or dual-certified WP316/316L fittings avoid sensitisation at the field welds. For pharmaceutical and food lines, polished fittings with controlled internal finish are available, and orbital-welded hygienic systems may use tube fittings to ASME BPE instead of pipe fittings. In warm seawater and strong chlorides, duplex or super duplex fittings are preferred over 316L.
For pharmaceutical, food and dairy systems, internal surface finish is often specified as a maximum roughness, with electropolishing for the cleanest surfaces. In chemical service, fittings in 316L are often ordered with an intergranular corrosion test to ASTM A262 Practice E, and with positive material identification so that 316L cannot be mixed with 304L fittings that look identical.
Ordering SS 316 pipe fittings
Please give the grade, fitting type, size, schedule or class, seamless or welded class (WP-S, WP-W or WP-WX), end connection, quantity and any IGC test, polishing or third-party inspection requirement. Fittings are packed in wooden boxes with bevel protection.
Applications and related products
SS 316 pipe fittings are used in chemical and petrochemical plants, pharmaceutical and biotech facilities, dairy and food processing, desalination pre-treatment, marine and offshore utilities, pulp and paper, and water treatment. Other stainless fittings are on the stainless steel pipe fittings page and all materials on the pipe fittings page. In the same grade we also supply SS 316 pipes, SS 316 flanges, SS 316 sheets and plates and SS 316 round bars.
Frequently Asked Questions
ASTM A403 (ASME SA403) covers wrought austenitic stainless steel fittings, including WP316 and WP316L. Dimensions follow ASME B16.9.
WP316L has a lower maximum carbon content for welded systems, with slightly lower minimum strength. Fittings are often dual certified.
WP-S fittings are seamless; WP-W fittings are welded with the fitting maker's welds radiographed; WP-WX fittings are welded with all welds radiographed.
Yes. Fittings are solution annealed and quenched after forming, then pickled and passivated.
Yes. Socket weld and threaded fittings in ASTM A182 F316/F316L are made to ASME B16.11 in Class 2000 to 9000.
Butt-weld fittings from ½" to 24" NB, with larger welded sizes on request, and forged fittings from ¼" to 4" NB.
Request a Quote for SS 316 Pipe Fittings
Tell us the product, grade, size, standard, quantity and delivery location, and our sales team will reply with a quotation.