5 Conclusion By improving the material composition and manufacturing process of GRP, the overall mechanical properties of GRP have been improved, and the shortcomings of brittleness of chopped GRP reinforced GRP have been overcome. According to the shell test, the glass fiber reinforced plastic pneumatic ball valve designed according to PN6 can be used safely under the working condition of PN25 at least. The application scope of the FRP pneumatic ball valve is widened, and the corrosion resistance of the FRP pneumatic ball valve is fully exerted.

The disassembled individual parts can be cleaned by immersion. The metal parts that have not been decomposed can be scrubbed with clean, fine and clean silk cloth impregnated with cleaning agent (to avoid fiber falling off and adhering to the parts). All grease, dirt, glue and dust adhered to the wall surface must be removed during cleaning.
The non-metallic parts shall be taken out of the cleaning agent immediately after cleaning, and shall not be soaked for a long time.