Butterfly valve life The normal failure mode of […]
Butterfly valve life
The normal failure mode of the butterfly valve is leakage. The leakage includes external leakage and internal leakage. The external leakage is mainly caused by erosion or corrosion. The internal leakage is mainly caused by the damage of the sealing pair. The commonly used life refers to the use time or the number of actions of the seal pair, which mainly depends on the type of medium, medium temperature, medium pressure, opening and closing frequency, opening and closing speed, etc., so that materials satisfying the working conditions are selected and necessary Heat treatment, for example: material scratch resistance, electrochemical corrosion resistance and fatigue strength. In addition, the life of the sealing pair is closely related to the rationality of the structural design and the manufacturing precision.
Media sensitivity of butterfly valves
The butterfly valve is suitable for use as a switch or regulating device for conveying various media such as water, oil, gas, water-solid two-phase and gas-solid two-phase flow. Therefore, the sensitivity of the butterfly valve sealing pair to the medium is also considered in the design. One of the important factors is that the design is mainly based on material selection and structural form. For example, for a cutting butterfly valve with a high dust content in the medium, a rubber material with good elasticity is used as a sealing ring, or a multi-layer metal hard sealing ring with a self-cleaning structure is used, and the sealing body is sealed while the sealing pair is relatively moving. It can remove dirt such as particles, or use the purging and cleaning functions to reduce the dust pollution to the sealing pair.