Sealing Materials Selection
- Nitrile Rubber (NBR)
- Good oil resistance, suitable for most petroleum products, liquid and gas.
- However, it has poorer resistance to ozone, oxygen, and acids.
- Operating temperature: -20°C to +80°C.
- Ethylene Propylene Diene Monomer (EPDM)
- Good resistance to ozone and ultraviolet light, relatively better resistance to aging, and some resistance to weak acids and steam.
- Operating temperature: -20°C to +150°C.
- Silicone Rubber (SI)
- Excellent high temperature and low temperature performance, no odor and non-toxic, but not resistant to oil and acids.
- Suitable for food industry.
- Operating temperature: -60°C to +200°C.
- Fluorocarbon Rubber (FKM)
- Excellent high-temperature resistance, aging resistance, and good chemical resistance.
- Expensive, and typically used for high-quality seals.
- Operating temperature: -20°C to +150°C.
- Polytetrafluoroethylene (PTFE)
- Excellent chemical resistance, can be used in any type of fluid, high-temperature resistance.
- However, due to its lower hardness, its sealing effect in high-pressure environments is less effective.
- Operating temperature: commonly used in steam, high-temperature environments.
This is a summary of various types of rubber materials and their respective properties.
Valve Body and Seal Selection Table
Item | Brass | Cast Iron | Stainless Steel | Plastic | NBR | EPDM | VITON FKM |
PTFE |
---|---|---|---|---|---|---|---|---|
Air | √ | √ | √ | √ | √ | √ | √ | √ |
Natural Gas | √ | √ | √ | √ | √ | √ | √ | |
Oxygen | √ | √ | √ | √ | √ | √ | √ | √ |
Hydrogen | √ | √ | √ | √ | √ | |||
Coal Gas(City) | √ | √ | √ | √ | ||||
Coal Gas(Industrial) | √ | √ | √ | √ | ||||
Nitrogen | √ | √ | √ | √ | ||||
Delicacy oil | √ | √ | √ | √ | √ | |||
Water | √ | √ | √ | √ | √ | √ | √ | √ |
Warter steam | √ | √ | √ | × | √ | √ | √ | |
Drink Steam | √ | √ | √ | √ | √ | √ | ||
Sea Water | √ | √ | √ | √ | √ | √ | √ | |
Industrial Waste Water | √ | √ | √ | |||||
Bio-alcoholic oil | √ | √ | √ | |||||
Gaslolene | √ | √ | √ | × | √ | √ | ||
Coal oil | √ | √ | √ | √ | √ | × | √ | √ |
Diese oil | √ | √ | √ | √ | √ | × | √ | √ |
Milk | √ | √ | √ | √ | √ | √ | √ | √ |
Wine | √ | √ | √ | √ | √ | √ | √ | √ |
Alcohol | √ | √ | √ | √ | √ | × | √ | |
Methanol | √ | √ | √ | |||||
Acetylene | √ | √ | √ | √ | √ | × | √ | √ |
Ethanol | √ | √ | √ | √ | √ | × | √ | √ |
Acetone | √ | √ | √ | × | × | × | √ | |
Ammonia | √ | |||||||
Toluene | √ | √ | √ | √ | × | √ | √ | |
Dimethy Ibenzene | √ | √ | √ | √ | × | √ | √ | |
Dimethy Imethane | √ | √ | √ | √ | √ | × | √ | √ |
Methane | √ | √ | √ | √ | × | √ | √ | |
Sulfur Dioxide | √ | √ | √ | √ | √ | √ | √ | |
20%Sodium Hydroxide<20% | √ | √ | √ | × | √ | |||
<10%Nitric Acid<10% | √ | √ | √ | √ | ||||
<20%Sulfric Acid<20% | √ | √ | √ | |||||
Hydrochloric Acid10% | √ | √ | ||||||
Vinegar Acid | √ | √ | √ | √ | √ | × | √ | √ |
√ Satiafactory ×Unsatisfactory Blank:Test(May or May not be Used) |