WHAT IS A GASKET?
A Gasket in piping, is a sealing material placed between connecting flanges to create a static seal. The gasket prevents leakage betweek the flanges in all operating conditions. There are various types of gaskets used to create the leak proof sealing between the flange faces.
Tesco Steel & Engineering is a leading manufacturer, exporter and stockist of gaskets.
TYPES OF GASKETS
Gaskets used in piping are of three main types:
Metallic gaskets are manufactured from metals like stainless steel, carbon steel, soft iron, monel and inconel. These gaskets are also known as Ring Gaskets / RTJ Gaskets.
High pressure class flanges (generally more than 900 class). Also used for extreme temperatures.
These metallic gaskets require high tension bolting.
Metallic Gaskets are highly durable
They are most costly
These metallic gaskets are used with RTJ flanges. The gasket fits in the groove on the flange face of both joint flanges. Metallic flanges are of two types: Octagonal and Oval.
Non-Metallic gaskets are made from PFTE, Graphite, Teflon, Rubber and Compressed Non-Asbestos Fiber (CNAF).
Features of non-metallic gaskets:
Cheaper as compared to others
Used with low pressure class flanges such as 150 class/300 class. They are used in low temperature applications.
Non-Metallic gaskets easily compress with low tension bolting
Non-Metallic Gaskets can be of types:
Full Face (suitable for flat face flanges)
Inside Bolt Circle (suitable for raised face flanges)
COMPOSITE GASKET / SEMI-METALLIC GASKET
Composite gaskets are made by combining metal and non-metal materials. Most widely used composite gaskets are: Spiral wound gaskets, metal jacketed gaskets and kamprofile gasket. Different service requires different combination of materials. Composite gaskets are used on:
Raised face flanges
Tongue and groove flanges
SPIRAL WOUND GASKET
Spiral wound gaskets are the most popular type of composite gasket. Spiral wound gaskets are made of three main components:
Inner and Outer rings
Generally, filler material is made from graphite or PTFE. Winding material is made from stainless steel, carbon steel or other exotic materials.
KAMMPROFILE / CAMPROFILE GASKET
Kamm / Cam profile gasket have a solid metal core with concentric grooves. Filler material is layered on this grooved metal ring made of graphite or PTFE. Kammprofile gasket provides better blowout resistance and are easy to handle even in large diameters. Kammprofile gaskets are costlier than spiral wound gasket.
METAL JACKETED GASKET
Metal jacketed gasket has a soft filler material enclosed in a thin sheet of metal jacket. Jacketed gaskets can be easily fabricated in a variety of sizes and shapes. They are commonly used in heat exchangers and valves.