Spiral wound gaskets are made from winding the strips of metal as well as filler material. The winding material and filler are changed according to the needs of chemical characteristics and compatibility. Spiral wound gaskets are mainly divided according to the materials used in them. There are different kinds of spiral wound gasket material that you may come across. Go through following details to explore what each one of those has got:
What are the Different Kinds of Spiral Wound Gaskets
Metallic gaskets
These are made from the different combinations of metal in specific size and shape. Lens rings gaskets and ring joints gaskets are the ones that usually fall under this type. These are more suitable for high temperature and extreme pressure applications. To seal them, they need high bolt load that facilitates sufficient deformation. Metallic gaskets have a tremendous ability to handle sudden fluctuations in pressure and temperature. It can withstand the pressure limit of up to 10,000 psi, but it also means that there will be hardly any compression. The bolt force creates an extreme pressure on seal interface that allows the gasket metal to flow into the flange material structure thereby producing a tight seal.
The common problem that metallic gaskets face is that they are highly susceptible to the galvanic corrosion. However, this issue can be overcome by keeping gasket material very close to the flange material.
Semi-metallic gaskets
These kinds of gaskets play an important role to curtail the gap between metallic gaskets and non-metallic gaskets. These are mainly manufactured from the metallic and non-metallic material as a result of that they possess features of both the materials. The metallic part gives sealability, while the non-metallic portion offers resilience and strength. Semi-metallic gaskets are manufactured to tolerate any form of the condition that involves extreme pressure and high temperature.
The winding material selection is made by fluid concentration, cost of the material, corrosive nature and operating temperature. Stainless steel 321, 316 and 304 is a frequently used material for winding. In some of the cases, alternative materials can be used. Graphite and asbestos are also used as general filler material, but in extreme temperature conditions, graphite is a most preferred choice. Gaskets feature outer ring manufactured from the carbon steel material to achieve precise positioning. In case of exceptional applications, they also come with the inner ring. To produce best results, the process fluid and ring material must be compatible with each other.
Non-metallic gaskets
These are manufactured from the materials which are easy to compress such as silicone, PTFE, graphite, NBR, etc. They can resist the corrosion but only up to the limited temperature. Non-metallic gaskets have many restrictions when it comes to the high-pressure conditions. Flat ring gasket form can be used with raised face flanges, while full face gasket is easy to go with flat face flanges.
The difference between the kinds of spiral wound gaskets mentioned above will definitely help you to pick a right type of gasket according to your requirement. So go ahead, make an informed decision and order your chosen gasket here.
