The sealing surface of the valve has soft sealing and hard sealing. Soft sealing common are Rubber, Fluoroplastics, Nylon Plastic, Enamel, Ceramics, etc. Generally used for normal temperature and atmospheric pressure pipelines. Hard sealing common Hard alloy, Copper alloy, Monel, Babbitt alloy, Boron steel, Nitrided steel, Lead lining, stainless steel, etc.
| Seat sealing surface | suitable for temperature | Seat sealing surface | suitable for temperature |
| Babbitt alloy | <100℃ | Nylon plastic | <100℃ |
| Enamel | <150℃ | Boron steel | 850~950℃ |
| Nitrided steel | <540℃ | Line with lead | <90℃ |
| Fluoroplastic | Theoretical temperature 180℃ and realistic temperature of 150℃ | Mo2Ti stainless steel | -196~600℃ |
| Pottery and porcelain | >150℃ | Plastic | Up to 50℃, below 50℃ is recommended |
| Cr13 series stainless steel | 200℃~300℃ | Copper alloy | 200℃~300℃ |
| Line with rubber | 80℃ | Rubber | 80℃ |
| Monel metal | -240~+482℃ | Carbide | 200℃~300℃ |
A wide range of valve sealing surfaces are:
- Fluoroplastics: high-temperature resistance, chemical corrosion resistance, low friction coefficient, but low mechanical strength, easy creep, small elasticity. It is suitable for corrosive medium with a temperature of less than 170 degrees.
- Cr13 series stainless steel: corrosion resistance is good, usually used in water, steam, and oil products, temperature not more than 300 degrees medium.
- Lining glue: with high strength, corrosion resistance is good.
- Plastic: can be used in almost all media, and wear resistance is very good.
- Copper alloy: copper alloy in water or steam corrosion resistance and wear resistance are good, suitable for PN ≤1.6 mpa and the temperature does not exceed 200 degrees medium.
- Rubber: excellent corrosion resistance, resistance to almost all chemicals, but low temperature performance is not good, poor radiation resistance.
- Carbide: corrosion resistance, erosion resistance and abrasion resistance, and other comprehensive performance is very good, suitable for a variety of different purposes of valves and a variety of different media, especially strong corrosive media.
Select the valve sealing surface to first consider the applicable temperature, and then consider the valve used in the scene, such as the valve for not more than 300 degrees of steam, whether or not corrosive steam, Cr13 series stainless steel can be used as valve sealing surface.
