It is fully compliant with over-water conditions and is a type of soft-seal butterfly valve. It has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical properties, oil filling and room temperature fluidity. It can be used in ozone, weather and UV resistant applications. However, based on its own structural characteristics, the flame retardancy, oil resistance and cohesiveness of the EPDM butterfly valve will be poor. Now let's take a look at the specific characteristics of the EPDM butterfly valve:
1. Low density and high filling:
The seat material in the EPDM butterfly valve is a lower density rubber. The oil can be filled in a large amount and the filler is added, so that the cost of the rubber product can be reduced, which makes up for the disadvantage that the price of the EPDM rubber is high. And the physical and mechanical properties of the valve seat sealing surface are not greatly reduced after high filling.
2. Ageing resistance:
The common feature of EPDM butterfly valves is that they are not resistant to high temperatures. It can be used at 120 °C for a long time, and can be used temporarily or intermittently at 150-200 °C. However, manufacturers will now try to add suitable anti-aging agents to improve the valve temperature. The EPDM cross-linked EPDM butterfly valve can be used under more severe conditions.
3. Corrosion resistance:
EPDM butterfly valves have excellent resistance to various polar chemicals such as alcohols, acids, bases, oxidants, refrigerants, detergents, animal and vegetable oils, ketones and fats. However, it is less stable in some media such as gasoline, benzene and mineral oil. Therefore, it is not suitable for oil, and its performance is also reduced under the long-term action of concentrated acid.
4. Water vapor resistance:
The EPDM butterfly valve is far superior to the performance of fluorine rubber, silicone rubber, fluorosilicone rubber, butyl rubber, nitrile rubber and natural rubber under the same conditions.
5. Resistance to overheating:
The EPDM butterfly valve is no problem when it is overheated. Its mechanical properties change little and the volume expansion rate is low. However, it is closely related to the vulcanization system used.
6. Electrical performance:
The electrical properties of EPDM butterfly valves are very close to or even better than those of styrene-butadiene rubber, polyethylene and cross-linked polyethylene. It is very good for electrical insulation and corona resistance.
In terms of elasticity, the EPDM butterfly valve is second only to natural rubber and butadiene rubber and can be maintained at low temperatures.
EPDM rubber has low cohesive energy due to lack of active groups in the molecular structure, and the rubber compound is easy to bloom, and its self-adhesiveness and mutual adhesion are very poor.