For acid and alkali storage tanks, is it better to use breathing valves made of all plastic (PP/PVC) or those with an inner lining?
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Many large-scale petrochemical and pharmaceutical projects today have storage tanks for highly corrosive substances. To maintain pressure balance inside and outside the tank and reduce vapor loss of the liquid contained within, a vent valve is usually installed on the top of the tank. Previously, there were no breathing valves made entirely of plastic (PP/PVC); instead, cast steel or stainless steel linings were used. However, due to the high corrosiveness of the medium, these linings had to be replaced after a short time, but it was still a solution. In recent years, Beijing Jingchen Petrochemical Company has developed all-plastic (PP/PVC) breather valves for such applications. These valves are now widely used in various petrochemical and pharmaceutical industries. In most cases, they function without any problems; however, some customers still encounter issues after using them due to differences in specific operating conditions. What do you think – for the selection of breather valves for acid and alkali storage tanks, is it better to use all-plastic (PP/PVC) materials or ones with an inner lining?
This post was last edited by sifangok on 2016-11-2 at 20:23: Use plastic when temperature and pressure are low – it’s cheap; use lining when temperature or pressure is high – it’s safer
All-plastic valves are fine for use indoors, but when exposed to wind and sun outdoors all year round, their reliability is not as good as that of those with a steel lining