SS 316 Seamless Pipe - ASTM A312 TP316 Stainless Steel Pipe

Product Description

SS 316 Seamless Pipe to ASTM A312 / ASME SA-312

Seamless pipe in grade TP316 (UNS S31600), a molybdenum-bearing austenitic stainless steel, to ASTM A312/A312M (active edition A312/A312M-25) and ASME SA-312, its ASME Section II-A counterpart. A312 covers austenitic stainless steel pipe for high-temperature and general corrosive service. Seamless means no welding at any stage: pipe is hot finished or cold drawn, then solution annealed at 1040 C minimum and quenched in water or rapidly cooled. Finishes: solution annealed and pickled, or bright annealed; passivated on request.

Grade, Composition and Equivalents

Chemical composition, C 0.08 max, Mn 2.00 max, P 0.045 max, S 0.030 max, Si 1.00 max, Cr 16.0-18.0, Ni 11.0-14.0, Mo 2.0-3.0.
Mechanical, minimum: tensile 515 MPa (75 ksi), yield 205 MPa (30 ksi), elongation in 50 mm 35% longitudinal, 25% transverse.

• AISI 316
• UNS S31600
• EN 1.4401 / X5CrNiMo17-12-2
• JIS SUS 316
• BS 316S31 (superseded by EN)

Sizes and Dimensions

Dimensions to ASME B36.19M: NPS 1/2 to 24 (OD 21.3 to 610 mm) in Sch 10S, 40S and 80S. The standard also lists Sch 5S. A312 permits other dimensions, so heavier walls such as Sch 160 and XXS are taken from ASME B36.10M. NPS 1/8 to 8 come in lengths up to 7.3 m (24 ft), with a permissible range of 4.6 to 7.3 m, and cut lengths can be ordered. Ends: plain (PE). The full size and weight table is in the listing images. Sample rows (wall mm / kg per m, at a density of 7980 kg/m3):

Standards and Tests

Tests required by ASTM A312:

• Tension test, transverse or longitudinal: 1 per lot of up to 100 pipes, 2 for larger lots
• Flattening test on 5% of pipe from each heat-treated lot
• Hydrostatic test or nondestructive electric test on each pipe
• Chemical analysis to A312 Table 1

Only when ordered: intergranular corrosion test to ASTM A262 Practice E (A312 Supplementary Requirement S7), PMI, ultrasonic examination (UT) and third-party inspection to EN 10204 3.2.

Applications and Industries

Molybdenum gives 316 better corrosion resistance than 304, particularly against pitting and crevice corrosion in chlorides. The grade keeps excellent toughness down to cryogenic temperatures. It is usually called marine grade but is not fully resistant to sea water. It is subject to pitting and crevice corrosion in warm chlorides and to stress corrosion cracking above about 60 C. Oxidation limit in air: 870 C intermittent, 925 C continuous (not a pressure-design limit).

• Chemical containers and process piping
• LNG plant piping
• Heat exchangers
• Food processing and laboratory equipment
• Marine fittings

Industries: chemical and petrochemical, LNG and cryogenic, food and beverage, pharmaceutical, marine.

Supply from Allied Metal & Tubes

Allied Metal & Tubes of Khetwadi, Mumbai, Maharashtra, established in 1993, are stockists and dealers of stainless steel pipes, tubes, sheets and plates, carbon steel seamless pipes, alloy steel pipes and other ferrous and non-ferrous metals. We are MSME registered and ISO 9001:2015 certified, and we supply across India. Send grade, NPS or OD, schedule, length and quantity for a quote.

FAQ

Is SS 316 pipe the same as ASTM A312 TP316?
TP316 is the A312 pipe designation for grade 316, UNS S31600. ASME SA-312 is the designation used in ASME pressure codes.

Should I use SS 316 or SS 304 pipe?
316 has 2-3% molybdenum, which gives better resistance to pitting and crevice corrosion in chloride service.

Which test certificate is usual?
EN 10204 type 3.1 mill test certificates are the usual supply basis. A 3.1 certificate covers only the tests it reports. PMI, UT, corrosion tests and third-party inspection must be ordered separately.