ASTM A312

ASTM A312 / ASME SA312 – Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes, used for high-temperature and general corrosive service.

ASTM A312 standard is equivalent to ASME SA312, download free in PDF.

Stainless Steel Grades

Stainless steel material are TP304, TP304L, TP304H, TP304LN, TP309S, TP309J, TP310S, TP310H, TP316, TP316L, TP316H, TP316TI, TP317, TP317L, TP321, TP321H, TP347, TP347H, ASTM A312 covers Austenitic stainless steels, duplex steels are often selected for critical applications.

Main stainless steel grades with chemical composition are listed.

Grade C Si Mn Cr Ni Mo S P
TP304 0,08 1,0 2 18 – 20 8 – 11 0,03 0,045
TP304L 0,035 1,0 2 18 – 20 8 – 13 0,03 0,045
TP316 0,08 1,0 2 16 – 18 10 – 14 2 – 3 0,03 0,045
TP316L 0,035 1,0 2 16 – 18 10 – 15 2 – 3 0,03 0,045
TP321 0,08 1,0 2 17 – 19 9 – 12 0,03 0,045

ASTM A312 Size and Dimension

ASTM A312 stainless steel pipe sizes and dimensions should conform to ANSI B36.19, nominal pipe size (NPS) ranges from NPS 1/8 [10.29 mm] to NPS 30 [762 mm], Schedule number for wall thickness from Sch 5s to Sch 80s, value stated respective for specific size, average wall and minimum wall pipe are available upon request.

Note over NPS 12 sizes are actual sizes, not like below NPS 12 size values.

ASTM A312 Pipe Dimensional Tolerance, the tolerance should be specified in accordance with ASTM A999.

OD tolerance WTH(mm)
10.3-48.3 +0.40/-0.80 +/-12.5%t
>48.3-114.3 +0.80/-0.08
>114.3-219.1 +1.60/-0.80
>219.1-457.2 +2.40/-0.80
>457.2-660.4 +3.20/-0.80
>660.4-864 +4.00/-0.08
>864-1219.2 +4.80/-0.08

Manufacture

Seamless, welded, Heavily cold-worked (HCW) pipe, when NPS small than 14, single longitudinal weld, when large than 14, longitudinal weld or shall be produced by forming and welding two longitudinal sections of flat stock when approved by the purchaser.

All pipe shall be heat treated condition to compliance to ASTM A312 requirement, minimum annealing temperature is not less than 1040 C, rapidly cooled, pipe should be free of scale, pickling is common method to achieve that, bright annealing finish is generally offered for small size pipe.

Other conditions are not specified on the specification should conform to ASTM A999.

Testing and inspection:

  • Mechanical Tests
  • Grain Size Determinations
  • Weld Decay Tests
  • Transverse or Longitudinal Tension Test
  • Flattening Test
  • Grain Size
  • Hydrostatic or Nondestructive Electric Test
  • Flattening Test(option)
  • Radiographic Examination(option)
  • Intergranular Corrosion Test(option)
  • Weld Decay Test(option)

ASTM A312 stainless steel pipes