Test method for impermeability of LPG semi-trailer

The tank body of the liquefied gas semi-trailer is made of Q345R. After flaw detection, hydro pneumatic test, on-site inspection by the Technical Supervision Bureau, issuance of the pressure vessel inspection certificate, and completion of external rust removal and painting, etc. After the storage tank is completed, it shall be penetrated to see if there is any weld crack.

According to the Regulations on Safety Supervision of Special Equipment, pressure vessels are special equipment, and their design, manufacture, installation, transformation, maintenance, use and inspection are included in the supervision scope of the quality supervision, inspection and quarantine departments at all levels of the government. Penetrant testing is an important testing method for pressure vessels such as LPG semi-trailer.

Classification of penetrant testing methods:

Type of removal solvent: halogens, non halogens and special application solvent removers

Removal methods of penetrant: water washability, lipophilic post emulsification, hydrophilic post emulsification and solvent removal penetrant testing method.

Developer type: dry powder, water-soluble, water suspension, non-aqueous, special application developer and self developer.

Sensitivity grade of penetrant testing: very low, low, medium, high and super high sensitivity.

Dye components contained in penetrant: fluorescence, coloring and fluorescent dye penetrant testing.

Scope of application of penetrant testing:

Penetrant testing can be effectively applied to the inspection of non porous metal and non-metallic materials. When penetrant testing is applied to the inspection of powder metallurgy products, attention should be paid to distinguish whether the powder metallurgy products are porous products or dense products. If they are dense products, conventional penetrant testing methods can be used for testing.