ASTM A312 & A778
Standard: ASTM A312/A778,ASME B36.19M,ASME B36.10M
Alloy: 301,304/304L, 305,316/316L,430,409L(DIN 1.4301,1.4307,1.4401, 1.4404)
ASTM A312 Vs ASTM A778
A778 is suitable for small bore thin walled piping applications and A312 is used for large bore and higher pressure
ASTM A778 and A312 Pipes are available in schedule 5S, 10S, 40S, 80S, STD and XS in wall thickness (WT)
A778 Fabrication is better compared to ASTM A312
ASTM A312/ASTM A778 Specification
| Nominal Diameter | Outside Diameter | Nominal Wall Thickness | |||
| SCH5S | SCH 10S | SCH 40S | |||
| N.B | NPS | mm | mm | mm | mm |
| 8 | 1/4 | 13.72 | 2.24 | ||
| 10 | 3/8″ | 17.15 | 2.31 | ||
| 15 | 1/2* | 21.34 | 1.65 | 2.11 | 2.77 |
| 20 | 3/4″ | 26.67 | 1.65 | 2.11 | 2.87 |
| 25 | 1* | 33.4 | 1.65 | 2.77 | 3.38 |
| 32 | 1-1/4″ | 42.16 | 1.65 | 2.77 | 3.56 |
| 40 | 1-1/2″ | 48.26 | 1.65 | 2.77 | 3.68 |
| 50 | 2* | 60.33 | 1.65 | 2.77 | 3.91 |
| 65 | 2-1/2″ | 73.03 | 2.11 | 3.05 | 5.16 |
| 80 | 3* | 88.90 | 2.11 | 3.05 | 5.49 |
| 90 | 3-1/2″ | 101.60 | 2.11 | 3.05 | 5.74 |
| 100 | 4″ | 114.30 | 2.11 | 3.05 | 6.05 |
| 125 | 5* | 141.30 | 2.77 | 3.4 | 6.55 |
| 150 | 6* | 168.28 | 2.77 | 3.4 | 7.11 |
| 200 | 8* | 219.08 | 2.77 | 3.76 | 8.18 |
| 250 | 10* | 273.05 | 3.40 | 4.19 | 9.27 |
| 300 | 12* | 323.85 | 3.96 | 4.57 | 9.52 |
Large diameter stainless steel pipe
ASTM A312/ASTM A778 WELDED PIPE Specification
| Nomina Diameter | Outside Diameter | Nominal Wall Thickness | ||||
| SCH 5S | SCH 10S | SCH 20S | SCH 40S | |||
| (A) | (B) | mm | mm | mm | mm | mm |
| 350 | 14 | 355.6 | 3.96 | 4.78 | 7.92 | 11.13 |
| 400 | 16 | 406.4 | 4.19 | 4.78 | 7.92 | 12.7 |
| 450 | 18 | 457.2 | 4.19 | 4.78 | 7.92 | 14.27 |
| 500 | 20° | 508.0 | 4.78 | 5.54 | 9.53 | 15.09 |
| 550 | 22 | 558.8 | 4.78 | 5.54 | 9.53 | 15.09 |
| 600 | 24 | 609.6 | 5.54 | 6.35 | 9.53 | 17.48 |
| 650 | 26 | 660.4 | 5.54 | 7.92 | 12.7 | 17.48 |
| 700 | 28″ | 711.2 | 5.54 | 7.92 | 12.7 | 17.48 |
| 750 | 30° | 762.0 | 6.35 | 7.92 | 12.7 | 17.48 |
| 800 | 32″ | 812.8 | 7.92 | 12.7 | 17.48 | |
| 850 | 34* | 863.6 | 7.92 | 12.7 | 17.48 | |
| 900 | 36 | 914.4 | 7.92 | 12.7 | 19.05 | |
| 1000 | 40° | 1016.0 | 9.53 | |||