Selection (choice of baosteel, tianjin TPCO, smoke treasure, baotou steel, Chang Bao, cr steel raw materials, such as requirements within the outer diameter is smooth, uniform wall thickness, selection of high manganese steel pipe to ensure that products beautiful) - material inspection (measurement, chemical composition inspection) - storage - material cutting (leave enough machining allowance, removing iron and burr) - intermediate frequency heater variable diameter and bending forming (mold every 48 hours after grinding push system, ensure the dimensional tolerance control) - heat treatment (tempering process) - end processing (groove Angle 37.5 + 0.25 by 90 degrees of numerical control lathe, ensure the groove Angle and the height of the center,According to the size of the diameter to match the different blunt edge, (the role of the blunt edge: 1. Ensure that the end face is straight when welding the pipe fitting and the steel pipe, 2. Ensure that the bottom of the first argon arc welding is not burned through) to ensure that the welding is smooth.Without strain), visual inspection (appearance, peeling, pockmark) - chemical composition analysis (imported hand-held spectrometer) - dimensional inspection (outer diameter, wall thickness, ovality, straightness) - mechanical performance test (squashed, flaring) - sand (fine sand in order to ensure that the surface pitting not too - spray paint (environmental protection coating equipment coating surface evenly) - printing (code printer code on a black white, bright font) - packaging (wooden cases or pallet packaging, packaging with fixed, plastic film outside package water-proof, dust) - product check (forklift trucks, lifting transport, light with light, neat)