1.Working medium

According to the different working media, it is necessary to choose materials with good corrosion resistance. For example, if the medium is saltwater or seawater, aluminum bronze valve disc can be selected; If the medium is strong acid or alkali, tetrafluoroethylene or special fluororubber can be selected as the material for the valve seat.

2.Working pressure and temperature

rubber seal butterfly valve need to operate normally within the specified working pressure and temperature range, so it is necessary to choose materials with sufficient strength and temperature resistance.

3. Environmental conditions

Consider the environmental conditions in which the valve is located, such as humidity, salt spray, etc., and choose the appropriate material. 

4.Valve body material

The valve body materials of flange butterfly valve include gray cast iron, ductile iron, cast steel, stainless steel, etc. Among them, stainless steel has the best performance, but the cost is relatively high. If it is in a low-pressure environment, the performance of ductile iron material can be comparable to that of cast steel material, and the cost of using ductile iron material is lower.

5.Valve seat material

The seat materials of worm gear butterfly valve include rubber and fluoroplastics. Rubber valve seats can be used in weakly acidic and alkaline media such as water, steam, and oil, with good sealing performance; Fluoroplastic valve seats are used in highly corrosive media.

6. Butterfly disc material

The butterfly disc materials for manual butterfly valves mainly include ductile iron and stainless steel. Sometimes, in order to adapt to more complex media environments, it is necessary to wrap the butterfly disc with glue or PTFE material.

7.Valve shaft material

Most of them are made of stainless steel material, and special circumstances can be customized according to needs.

8.Drive material

There are two main manual operation methods, the handle and the worm gear. The handle materials mainly include cast iron, carbon steel, stainless steel, aluminum alloy, etc; The material of the worm gear head is mostly cast iron.

In summary, the material quality selection of manual butterfly valve should comprehensively consider factors such as working medium, working pressure and temperature, environmental conditions, as well as the materials of the valve body, valve seat, butterfly disc, and valve shaft. The correct material selection can ensure the normal operation and service life of water butterfly valve.