Spiral wound gasket is one of the widely used gaskets. Spiral wound gasket provides a low-cost seal that can be used under operating temperature and pressure fluctuations. The sealing spacer formed by the winding of multi-layer metal and filler effectively reduces the possible leakage.
The spiral wound gasket is made of formed metal tape and soft filler material alternately. A very effective seal is formed when it is compressed between two flanges.
The V-shaped protrusion of the middle part of the metal belt acts like a spring, giving the gasket good resilience when the working condition changes. Different materials can be selected for filler materials and metal strip materials to adapt to different chemical media.
Flexible graphite can be selected as the filling material if fire safety is required. If the effective compression load of the gasket is limited, the structure and size of the gasket can be modified to achieve effective sealing.
A spiral wound gasket can include an outer ring, an inner ring or both. The outer ring aligns the gasket with the flange as the limit of gasket compression. The inner ring can not only provide additional radial strength, but also reduce the erosion of the flange and protect the sealing elements.
The good resilience and high strength make the spiral wound gasket an ideal choice under various service conditions and working conditions. It is widely used in oil refineries and chemical plants.
Factors affecting gasket sealing performance
Sealing is achieved by compressing the gasket material and making it fill the uneven sealing surface. The sealing can effectively prevent the leakage of medium. In order to maintain this working condition, sufficient load must be applied to the connection part to resist the hydrostatic pressure on the end face caused by the internal pressure of the system.
The use of gaskets depends on many factors, including:
1. Metal materials and filler materials must be able to withstand the influence of the following factors:
a. Temperature: temperature has adverse effects on the mechanical and chemical properties of the gasket, as well as the physical properties of the gasket, such as oxidation and resilience.
b. Pressure: the medium or internal pressure of the pipe may blow the gasket out of the flange surface
c. Medium: gasket material must be resistant to medium corrosion
2. Connection design: the force of two flange connections must be sufficient to prevent flange separation caused by the hydrostatic pressure of the end face generated by the internal pressure of the system.
3. Suitable bolt load: if the bolt load is not large enough, the deformation of the gasket cannot meet the requirements, or the load is too large and the gasket is crushed, leakage will occur.
4. Surface processing: if the surface processing does not meet the gasket requirements, it will not have a good sealing effect.