Sealing Materials Selection

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.

Diaphragm Solenoid Valves

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)