seamless pipe produce tech
PIC-(seamless pipe produce tech)
| Type of steel tube | Steel tube size mm |
Deviation | ||
| Ordinary grade | Senior | |||
| Hot rolling (extrusion, expansion) tube | Outside diameterD | All | +1%（Minimum+0.50） | - |
| Wall thicknessS | All | +15%（Minimum+0.45） -12.5%（Minimum-0.40） |
- | |
| Cold drawing (rolling) tube | Outside diameterD | 6~10 | +0.20 | +0.15 |
| >10~30 | +0.40 | +0.20 | ||
| >30~50 | +0.45 | +0.30 | ||
| >50 | +1% | +0.8% | ||
| Wall thicknessS | ≤1 | +0.15 | +0.12 | |
| >1~3 | +15% -10% |
+12.5% -10% |
||
| >3 | +12.5% -10% |
+10% | ||
| Note: the outer diameter is not less than 351mm of the thermal expansion tube, the wall thickness allows the deviation of +18% | ||||