ERW pipes means Electric Resistance Welded Pipes. ERW steel pipes and tubes are used.
- ERW Pipe Manufacturing Processes
- Welded Tube and Pipe Manufacturing Processes
- Electric resistance welding at a glance
ERW steel pipes and tube are available in various qualities, wall thicknesses, and diameters of the finished pipes.
Technical requirements | For oil and gas transport | For low pressure fluid conveying |
Material | Gr.b | Gr.b |
Pipe body diameter | D<508mm, ±0.75%; D≥508mm, ±0.75% | D≤168.3, ±1.0%; 168.3<D≤508,±0.75%; |
Wall thickness | D<508mm,+15.0%,-12.5%; D≥508mm, +17.5%,-10% | ±12.5% |
Bending | ≤0.2% | ≤0.2% |
Ovality | D≥508mm,≤±1% | ≤±0.75% |
Bevel | ≤1.59mm | ≤5mm |
Hydrostatic testing | 100% | 100% |
Nondestructive testing | 100% non-destructive weld inspection | Ultrasonic flaw detection is 100% |
ERW pipe technical requirements
ERW steel pipes and tubes are used in various engineering purposes, fencing, scaffolding, line pipes etc.- Yield strength of the N80 is higher than the J55 up to 173 ~ 206 MPa.
- On the same area of the sample, the elongation of N80 is higher than J55.
- Under the same size, the same sample orientation, the same minimum sample size, J55 grade couplings, coupling stock, coupling material, semi-finished and coupling attachment material can absorb lower than N80 steel grade.
- The nondestructive testing methods of seamless pipe,coupling stock, welded tube with J55 and N80 is differeent.
- J55 and N80 steel grade is not the same color: length greater than or equal 1.8m, J55 painted a bright green, N80 painted a red;
- J55 chosen by the manufacturer, or organize according to the order specified length normalized (N), normalizing and tempering (N & T) or quenching and tempering (Q & T). N80 is a whole, full-length heat treatment is mandatory. By the manufacturer selected for normalizing (N) or normalizing and tempering (N & T) + quenching (Q).