Medium compatibility description for vacuum pressure switches

The medium compatibility of vacuum pressure switches mainly depends on the materials of the components inside that come into direct contact with the medium, such as diaphragms and seals. Different materials have different tolerances to the medium.

Diaphragm material

Rubber-based diaphragms: Common ones include fluorosilicone rubber, nitrile rubber, silicone rubber, etc. Fluorosilicone rubber diaphragms have excellent oil resistance, solvent resistance and chemical corrosion resistance, and are compatible with a variety of liquids, including some corrosive media. Nitrile rubber diaphragms have good resistance to mineral oil, grease, etc., but they may age or be damaged in some strong oxidizing media. Silicone rubber diaphragms have good temperature resistance and chemical stability, but their resistance to certain organic solvents is relatively poor.

Metal diaphragms, such as stainless steel diaphragms, feature high strength and corrosion resistance. They are suitable for applications where material strength is highly demanded and the medium has certain corrosiveness. For instance, in some chemical production processes, they may come into contact with various corrosive media like acids and alkalis. Stainless steel diaphragms can effectively resist the erosion of these media.

Sealing material

EPDM (Ethylene Propylene Diene Monomer rubber) seals: They have excellent resistance to aging, ozone, heat and chemical corrosion. They have good resistance to various polar solvents and chemicals and are suitable for environments with high sealing requirements and corrosive media.

FPM (fluororubber) seals: They feature excellent oil resistance, high-temperature resistance and chemical corrosion resistance, and can maintain good sealing performance in high-temperature and highly corrosive medium environments. They are often used in industrial Settings with strict sealing requirements.

Influence of medium characteristics

Corrosiveness: If the medium is highly corrosive, such as strong acids or strong alkalis, it will corrode the metal parts and seals inside the switch, leading to leakage, damage or even failure of the switch. Therefore, when choosing a vacuum pressure switch, it is necessary to select materials with corresponding corrosion resistance based on the corrosiveness of the medium.

Viscosity: Highly viscous media may remain inside the switch, affecting the switch's action sensitivity and repeatability accuracy. For instance, some gel-like or paste-like media may adhere to the diaphragm or transmission components, causing the switch to fail to operate normally.

Temperature: The temperature of the medium also affects the performance of the vacuum pressure switch. High temperatures may cause changes in the performance of materials such as diaphragms and seals, such as softening and aging, thereby reducing the reliability and service life of the switch. Low temperatures may cause the medium to solidify or thicken, affecting the normal operation of the switch.