1. Before the inspection should understand the pipe name, material, specifications, welding process, heat treatment, groove type, wall processing surface, and the location of the welding joint center calibration.
2. The appearance quality and dimensions of the welded joint shall be qualified by inspection. The surface shape of the welded joint should be properly grounded and the smooth transition should be made. The processing surface of the inner wall should meet the requirements of ultrasonic inspection.
3. Inspection surface probe moving area should be removed welding splash, corrosion, oxide and grease, if necessary, the surface should be polished smooth, polished width at least for the probe movement range.