The most important part of the valve seal is the seal seat of the valve, also called the seal ring. It is an important part of a valve seal and directly contacts the medium in the pipeline. We know that the medium in the pipeline is all kinds of water, gas, particulate matter, acid and alkaline substances and so on. The valve seals use different materials to adapt to different media. What are the materials for the valve seal?
Valve seals are available in metal (hard seal) and non-metal (soft seal) materials.
1 Synthetic rubber
Compared with natural rubber, synthetic rubber has better oil resistance, temperature resistance, and acid and alkali resistance. General use of synthetic rubber temperature ≤ 150 °C, natural rubber ≤ 60 °C, synthetic rubber is generally used as a nominal pressure ≤ 16 kg of butterfly valves, gate valves, globe valves, check valves and other valves sealing seat material.
PTFE has good corrosion resistance, and is mostly used for sealing materials for valves, such as butterfly valves, gate valves, globe valves, and ball valves with temperature ≤ 232°C and nominal pressure ≤ 64 kg.
Nylon has the advantages of low friction coefficient and good corrosion resistance. This material is mostly used for ball valves and globe valve sealing materials with temperature ≤ 90°C and nominal pressure ≤ 32 kg.
Valve metal seal material:
1 gray cast iron
Gray cast iron can be used for sealing materials in butterfly valves, gate valves, globe valves, and plug valves with temperatures between -15°C and 200°C and nominal pressure ≤ 16 kg.
2 ductile iron
Ductile iron can be used as a sealing material in butterfly valves, gate valves, check valves, and ball valves that have a temperature between -30°C and 350°C and nominal pressure ≤ 40 kg.
3 Copper alloy
The commonly used copper alloy materials include 6-6-3 tin bronze and 58-2-2 manganese brass. Copper alloy wear resistance is good, suitable for temperature ≤ 200 °C, nominal pressure ≤ 16 kg of water and steam, often used in gate valves, globe valves, check valves, plug valves.
4 chrome stainless steel
Chrome stainless steel commonly used 2Cr13, 3Cr13, good corrosion resistance. It is commonly used in valves with medium temperature, ≤450°C, nominal pressure ≤32 kg, water, steam and oil.
5 Chrome nickel titanium stainless steel
Chromium nickel titanium stainless steel commonly used 1Cr18Ni9ti, this material has a good corrosion resistance, erosion resistance and heat resistance. It is suitable for steam, nitric acid and other mediums with temperature ≤600°C and nominal pressure ≤60kg. It is used in butterfly valves, globe valves and ball valves.