What are the materials of the main parts of the butterfly valve, like the body, disc, and seat?
1. Body materials:
Cast iron: the most common material in butterfly valves, mainly used in water systems, easily corroded, short service life, and is cheap.
Ductile iron: the performance is comparable with carbon steel in butterfly valves. It is generally used in pipes within the water system, and it is also a very widely used material in water systems.
Carbon steel: It can also be used in water systems, but it is not used widely. With high temperature and pressure resistance, it¡¯s commonly used in hard seal butterfly valves.
Stainless steel: It has good anti-corrosion and anti-corrosion properties and is mostly used in pipelines that require anti-corrosion and anti-rust, and the cost is high.
2. Disc materials:
The disc of the butterfly valve touches the medium in the pipeline directly, so the material of the disc is not as varied as the material of the body. Commonly used ductile iron, stainless steel, and bronze.
3. Seat materials:
The seat of the butterfly valve is used to ensure the tightness of the valve, especially the soft-sealed seat, which has very good sealing performance.
Common valve seat materials are as follows:
EPDM: suitable for water and steam at -20-120¡ãC;
NBR: suitable for oil at 0-80¡ãC;
PTFE: suitable for corrosive medium blow 200¡ãC;
Hard alloy: suitable for high temperature and high-pressure environment
In addition, seat materials also include natural rubber, silicone rubber, nylon, stainless steel, and so on.
