The seals material for a solenoid valve is an important role to ensure long working life for solenoid valve. Selecting the correct sealing material for your solenoid valve requires to consider below factors.
2）Temperature of the medium
3）Working pressure and burst pressure
XHnotion will describe the most common 5 seal materials available for solenoid valve.
1. Nitrile Rubber（NBR /Buna-N）
Main used for diaphragm, O rings and seal material, Suitable for air, gas, liquid, water, light oil etc, Fluid temperature -18℃ to 80℃. NBR is the most common and standard solenoid valve seals material. Nitrile Rubber is weak in terms of oxidising media such as acids and poor to resist the sunshine. NBR seals have a good abrasion and tear resistance.
(1) NBR seals are most commonly used with the following media: Water, Air, Different Fuels, Oils, and Gases, vacuum.
(2) NBR has a good resistance to:
(3) NBR has a poor resistance to:
2. EPDM Rubber (Ethylene Propylene Diene Monomer rubber)
Main used the temperature range above NBR, (Such as hot water, low pressure steam) suitable for the most of gas, liquid water. Fluid temperature -20℃ to 139℃. EPDM also has a good resistance to acids, alkalis and salts. However, if you require a product with a good resistance to oils, petrochemicals and concentrated acids, EPDM will not be suitable.
（1）EPDM seals are most commonly used with the following media: Hot /Cold Water, Steam, Air
(2) EPDM has a good resistance to:
- Oxidizing Chemicals
- Up to Medium Concentration Acids
- Fireproof hydraulic fluids
- Many Ketones and Alcohols
- Abrasion and Tearing
(3) EPDM has a poor resistance to:
- Most Oils and Fuels
- Aromatic and Aliphatic Hydrocarbons
- Halogenated Solvents
- Concentrated Acidsand Alkali
3. VITON (FKM) Rubber
Main used the place where NBR, EPDM can not be applied. Suitable for most of the gas, liquid water, gasoline, solvent etc. It is well know for its excellent heat resistance and Chemical compatibility, Fluid temperature -20℃ to 169℃.
(1) Viton seals are most commonly used with the following medium:
- Hot Water
- Salts Solution
(2) Viton has a good resistance to:
- Many Aggressive Chemicals
- Diluted Acids
- Weak Alkalis
- Mineral Oils
- Aliphatic and Aromatic Hydrocarbons
- Chlorinated Hydrocarbons
(3) Viton has a poor resistance to:
Teflon is a brand name for PTFE . Almost it can be suitable for all fluid. PTFE is non elastic (not flexible), as dynamic seal material, it will be leakage especially the medium is gas. But it is usually used for high temperature and high pressure solenoid valve.
(1) PTFE seals are most commonly used with the following media:
- Food industry
(2) PTFE has a good resistance to:
- Load reformation
- Most chemicals
(3) PTFE has a poor resistance to:
- Hydrofluoric acids
- Hot caustic solutions
Silicone is a common material selection for solenoid valves, often used in general purpose applications and are used at a consumer level for common household products. Silicone seals have a good resistance to weathering, cold temperatures, chemicals, electrics, oils and acids, hence their ability to adapt. Silicone seals offers a wide working temperature range from -54°C through to +232°C, but Silicone is a very soft material and therefore is not very good with higher pressure applications typically above 40 bar (depending on orifice size and design). XHnotion usually use silicone seals for food, beverage application.
(1) Silicone seals are most commonly used with the following media:
drinking water, beverage, low pressure air.
(2) Silicone has a good resistance to:
- Heat and Steam
(3) Silicone has a poor resistance to:
- Tensile strength
- Diesel fuels