A312 covers seamless, straight-seam welded, and heavily cold worked welded austenitic stainless steel pipe intended for high-temperature and general corrosive service.

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.

Stainless steel grades and chemical composition

tolerance of ASTM A312

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

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)