How to detect the quality of LPG storage tanks

Liquefied petroleum gas storage tank is an important equipment for containing liquefied gas. Liquefied gas is flammable and explosive. Therefore, in order to ensure safety, the material selection, manufacturing process and quality requirements of liquefied petroleum gas storage tank are very strict. The tank body must be made of Q345R special steel plate for class III pressure vessels, which has been manufactured through non-destructive damage detection, overall heat treatment, hydrostatic test, on-site inspection by the Technical Supervision Bureau, pressure vessel inspection certificate issued, external rust removal and painting and other processes.

The quality inspection of liquefied gas storage tanks is very important, and the welding quality inspection is also very particular. For the welding of different welding materials, the hardenability of the welded joints is different due to the difference in weldability and structure of the welded joints. Therefore, different inspection times should be selected for the welded joints of different welding materials to ensure the reliability of the inspection.

The inspection of welded joints shall be carried out after welding. Materials with delayed crack tendency shall be tested at least 24 hours after welding.

The inspection of heat treatment process performance shall be arranged after heat treatment.

The inspection of the head shall be carried out after stamping, otherwise it is invalid.

All workpieces subject to non-destructive testing must pass the visual inspection before non-destructive testing.

In addition to meeting the standard requirements, the surface of the workpiece to be tested shall be free of defects such as cracks, pores, craters, undercuts and visible slag inclusions. The spatter and slag on both sides of the welding joint must be removed.

For components subject to ultrasonic or surface flaw detection, in addition to meeting the provisions of the previous article, all rust, protective layer and dirt affecting the detection shall be removed, and the surface roughness shall meet the standard requirements.