Plastic valve material selection

The materials of plastic valves generally used are UPVC, CPVC, PVDF, PP, PPH, etc. Suitable materials should be selected for different media and working conditions. Generally the max working pressure of plastic valve is 1.0mpa. Therefore, only the composition, temperature and concentration of media need to be considered in the selection of plastic valve materials. In addition to the reference of material selection table, we can make a simple judgment of material use according to the temperature and media.

UPVC is a non-toxic, pollution-free and corrosion-resistant material. Generally, it is recommended to use at a max temperature 50 ℃. In addition to water supply and drainage applications, UPVC can be used for alkaline and weak acid media, but not suitable for strong acid. Although UPVC is non-toxic, it is not recommended to be used in drinking water system because UPVC is mixed by different additives some additives may not good to health. The impact strength of UPVC material is not good at low temperature, so it is not recommended to used at low temperature. UPVC Plastic valve is the most widely used plastic valves.

CPVC is a new type of engineering plastics which is made by chlorination of PVC resin. The corrosion resistance,heat resistance, acid resistance, alkali resistance, salt resistance and oxidant resistance, is higher than UPVC. The maximum operating temperature of CPVC can reach 110 ℃, and the long-term operating temperature is 95 ℃. However, there are some differences of heat resistance of CPVC raw materials from different manufacturers, so this must be considered in the selection. CPVC is suitable for general alkaline medium and weak acid medium, but it can not be used for strong acid medium. CPVC can be applied to drinking water system.

PP is a common plastic material with excellent properties. With chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high wear-resistant processing performance. it is flammable, working temperature range is - 30 ~ 80 ℃. It can resist the corrosion of acid, alkali, salt solution and various organic solvents. PP valve is generally suitable for alkaline medium and weak acid medium.

PPH is beta modified PP material, so that it has a uniform and fine Beta crystal structure. It has excellent chemical resistance, abrasion resistance, insulation and high working temperature. The working temperature can reach 100 degrees centigrade, non-toxic, and it is more resistant to high temperature, corrosion resistance and aging resistance than PP. PPH can be used in acid and alkali medium, especially for mixed acid medium. But the price is higher than PP.

PVDF has the characteristics of the strongest toughness, low friction coefficient, strong corrosion resistance, aging resistance, climate resistance and radiation resistance, and its long-term working temperature can reach 140 ℃. It has excellent corrosion resistance for strong acid and strong alkaline solution, so it is widely used in chemical industry, but the price of PVDF material is high, so the cost should be considered in selection.