The main equipment of ERW pipe mill line includes1. Uncoiler The hot-rolled steel coil is disassembled and sent to the leveling machine. It is divided into two unwinding methods: upper unwinding and lower unwinding.

The offset defect of ERW steel pipe, also called lap welding, refers to the misalignment of the two edges of the tube blank during welding. Even after the internal and external burrs are removed, traces of offset can still be seen on the inner and outer surfaces of the steel pipe.

After the precision bright seamless tube is heat-treated to obtain austenite, it is quenched at a temperature range of 450-600 °C. Or go through 350-600°C at a slow cooling rate after quenching at 650°C. Or after quenching at 650°C, 16Mn seamless steel pipes and 16Mn seamless steel pipes are heated for a long time in the temperature range of 350-650°C, which will cause aging of precision bright tubes.

The cross-rolling process of seamless pipes is a rolling process in which the rolled piece rotates along its own axis, deforms, and advances between two or three rolls with the same rotation direction and intersecting (or inclined) longitudinal axes.

It is one of the basic methods for pipeline anticorrosion to evenly and densely coat the surface of the rust-removed metal pipeline with paint to isolate it from various corrosive media.

For seamless pipes that have been used for a long time, the oil sludge and rust in the pipes solidify, causing the original pipe diameter to become smaller. Hydrogen sulfide gas produced by sludge precipitation in the pipe will cause environmental pollution and easily cause explosion. The acid and alkali substances in the wastewater are easy to corrode the pipe wall. Improper removal of foreign matter in the pipeline will cause pipeline blockage.