The standard for API Spiral Steel Pipe is SY/T5037-2000 (Spiral Seam Submerged Arc Welded Steel Pipe for Ordinary Fluid Transportation), which is a departmental standard. GB/T9711 is the national standard, and the requirements for steel pipes in the national standard are higher than those in the departmental standard. [1]

Main production process of the national standard spiral steel pipe

Opening - Upper Roll - Leveling - Butt Welding - Beveling - Shaping - Internal Welding - External Welding - Tube Cutting - Breaking - Subsequent Welding - Hydrostatic Testing

The main difference between the national standard spiral steel pipe and the departmental standard spiral steel pipe

1. Application (5037 is for general conveying pipeline steel pipes; 9711 is for industrial conveying steel pipes)

2. Inspection Method

3. Performance indicators

4. Standard national standard steel pipes do not allow Q235B material; they must be pipeline steel.

Sectional standard spiral steel pipes are mainly used symbols

D-----Nominal Pipe OD mm

T--Nominal Wall Thickness mm

M - Steel pipe line quality kg/m

P----Test Pressure for Hydrostatic Test in MPa

S--- Static water test stress in MPa

H----Weld Seam Rake mm

BSP (Bureau of Standards, Philippines) spiral steel pipe allows for a tolerance range.

GB/9711.1-1997 specifies:

Outer Diameter D < 508, Minus 12.5% Tolerance, Plus 15% Tolerance

>508, -10.0% T, +17.5T.