Sand holes is medium corrosion causes of pneumatic valve

I have less than a year of pneumatic valve device, appeared trachoma, media leaks, don't know what reason be? One is for the corrosive medium caused by the pneumatic valve outcasts, another cause slight blisters, over time, by the media and pipe pressure, also can appear this kind of situation the landlord said. Trachoma is mainly caused by poor casting, recommend and forging steel pneumatic valve is the next step. Medium leakage, said in a pneumatic valve, leakage is not allowed, it is strongly recommended that replacement as soon as possible! It is primarily in loose casting, the breakthrough pressure for a long time, so some movie actor, to prevent these problems, light pressure test may find these problems. Trachoma is aimed at the problem of the casting process of pneumatic valve manufacturers who are poor, in the pouring of mixed gas or mixed magazine and other reasons, the raw material can lead to leakage of the main causes of corrosion and wear problem.