What is included in the periodic inspection of pressure vessels?

Periodic inspection of pressure vessels includes external inspection, internal and external inspection and pressure resistance test;

The external inspection can be carried out during the operation of the pressure vessel. The inspection contents include:

(1) Cracks, overheating, deformation, leakage, etc. of the body, interface parts, welded joints, etc. of the pressure vessel.

(2) Corrosion of the outer surface; insulation layer is damaged, shedding, damp, running cold.

(3) Leakage and leaking of leak detection holes and signal holes; dredging leak detection tubes; discharge (hydrophobic, sewage) devices.

(4) The abnormal vibration and sound of the pressure vessel and adjacent pipes or members rub against each other.

(5) Conduct a safety accessory inspection.

(6) Damage to the support or support, the foundation sinks, tilts, cracks, and the fasteners are in good condition.

(7) Stable condition of operation; pressure vessel monitoring situation with level 4 safety status.

The internal and external inspections are carried out when the pressure vessel is out of service. The inspection contents are as follows:

(1) All items of external inspection.

(2) Structural inspection. The key inspection points are: the joint between the cylinder and the head, the opening, the weld, the head, the support or the support, the flange, and the sewage outlet.

(3) Geometric dimensions. Where there is information to confirm the geometry of the container, it is generally necessary to check the main dimensions. The geometric dimensions that may change during operation, such as the roundness of the cylinder, the head and the simplified bulging deformation, should be reviewed.

(4) Surface defects. Mainly: corrosion and mechanical damage, surface cracks, weld undercuts, deformation and so on. Careful inspection and measurement of surface defects should be carried out.

(5) Wall thickness measurement. The measurement position should be representative and have sufficient measurement points.

(6) Material. Determine if the material of the main pressure component is deteriorated.

(7) The integrity of the insulation layer, the surfacing layer and the metal lining.

(8) Inspection of weld burial defects.

(9) Inspection of safety accessories.

(10) Fastener inspection.

The withstand voltage test is a hydraulic test or a pneumatic test that exceeds the maximum working pressure when the pressure vessel is shut down. The withstand voltage test shall comply with the relevant provisions of the Pressure Vessel Safety Technical Supervision Regulations.