SS 304 Seamless Pipe - Stainless Steel ASTM A312 TP304

Product Description

SS 304 Seamless Pipe to ASTM A312 / ASME SA312

Stainless steel 304 seamless pipe in grade TP304 (UNS S30400) to ASTM A312/A312M (current edition A312/A312M-25) and to ASME SA-312. ASME pressure codes refer to the SA-312 designation. TP304 is the standard 18Cr-8Ni austenitic grade. Seamless pipe has no welding at any stage. It is made either hot finished or cold finished (cold drawn). ASTM A312 covers austenitic stainless steel pipe for high-temperature and general corrosive service. The pipe is solution annealed at 1040 C minimum and then cooled quickly. It is bright annealed and pickled to a uniform satin silver-grey finish, with plain ends (PE).

Grade, Equivalents and Properties

Equivalents: AISI 304, UNS S30400, EN 1.4301 (X5CrNi18-10), JIS SUS 304 (pipe marking JIS G 3459 SUS304TP), BS 304S31 (superseded by EN).

Chemical composition, ASTM A312 TP304 (%): C 0.08 max, Mn 2.00 max, P 0.045 max, S 0.030 max, Si 1.00 max, Cr 18.0-20.0, Ni 8.0-11.0.

Mechanical properties (min): tensile strength 515 MPa (75 ksi), yield strength 205 MPa (30 ksi), elongation in 50 mm 35% longitudinal and 25% transverse. Density 7930 kg/m3.

304 cannot be hardened by heat treatment. It resists corrosion in a wide range of atmospheric environments and many corrosive media. In warm chloride environments it can suffer pitting and crevice corrosion, and above about 60 C it can suffer stress corrosion cracking. It stays tough down to cryogenic temperatures. Its oxidation (scaling) limit in air is 870 C in intermittent service and 925 C in continuous service. This is not a pressure-design limit.

Sizes and Dimensions

Dimensions follow ASME B36.19M: NPS 1/2 to NPS 24 (OD 21.3 mm to 610 mm) in Sch 10S, 40S and 80S. The standard also lists Sch 5S. A312 allows other dimensions, so heavier walls such as Sch 160 and XXS can be supplied to ASME B36.10M. For example, NPS 2 Sch 40S is 60.3 mm OD x 3.91 mm wall and weighs 5.49 kg/m. Unless otherwise specified, A312 supplies NPS 1/8 to NPS 8 in lengths up to 7.3 m (range 4.6-7.3 m). Cut lengths can be ordered. The full size table (OD, wall and kg/m by schedule) is in the listing images.

Weight check: kg/m = (OD - WT) x WT x 0.02491, with OD and WT in mm.

Standards and Tests

• ASTM A312/A312M and ASME SA-312, grade TP304
• Dimensions to ASME B36.19M
• Tests required by A312: tension test, flattening test, hydrostatic test or nondestructive electric test on each pipe, and chemical analysis
• Done only when ordered: intergranular corrosion test to ASTM A262 Practice E (A312 Supplementary Requirement S7), PMI, UT, and third-party inspection (EN 10204 3.2)

In normal practice, A312 pipe is supplied with EN 10204 type 3.1 mill test certificates. A 3.1 certificate covers only the tests it reports.

Applications and Industries

• Food processing equipment, beer brewing, milk processing and wine making
• Chemical process piping and chemical containers
• Heat exchangers
• General-purpose process piping

Industries: food and beverage, chemical and petrochemical, pharmaceutical, oil and gas.

Supply from Allied Metal & Tubes

Allied Metal & Tubes, based in Khetwadi, Mumbai, Maharashtra, was established in 1993. We 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. For a quote, send the NPS or OD, schedule, length and quantity.

FAQ

Which standard covers SS 304 seamless pipe?
ASTM A312 grade TP304, which is ASME SA-312 in ASME pressure codes. Dimensions follow ASME B36.19M.

What is the weight of 2 inch SS 304 Sch 40 pipe?
NPS 2 Sch 40S is 60.3 mm OD with a 3.91 mm wall and weighs 5.49 kg/m.

What are the equivalents of SS 304?
AISI 304, UNS S30400, EN 1.4301 (X5CrNi18-10) and JIS SUS 304.

Can SS 304 pipe be used in chloride service?
Use care. 304 can pit and crevice-corrode in warm chloride environments, and above about 60 C it can suffer stress corrosion cracking.