Graphite Gasket
Soft Gasket

1.Graphite Gasket

Graphite is generally used in high temperature and high pressure environments and commonly finds applications in steam cycling or exhaust applications. These gaskets provide a higher performance seal in these conditions than non-asbestos jointing. Graphite has a low friction surface. Thus, it transcend in extreme conditions, resisting high pressures and temperatures.

Graphite gaskets combine strong thermal resistivity with resistance to thermal shock, a type of damage that occurs when components are subjected to rapid changes in temperature. Typically, these industrial gaskets are fabricated from expanded sheets and foil-core materials. Unlike other types of gasket materials, graphite’s mechanical properties increase with temperature. In multi-layer components, graphite can be interpose together with other gasketing materials to create custom sealing and insulation solutions. Graphite is also flexible and can be produced without fillers or binders that can limit sealing performance in demanding applications.

  Graphite  gaskets are preferred due to the following advantages:

• Resistance to high and low temperatures across a wide temperature range
• Corrosion resistance at most temperatures and pressures
• Exceptional mechanical strength
• Excellent resiliency
• High compressibility
• Low creep under temperature or pressure
• Unlimited storage life
• Resistance towards pH changes

 Due to these properties, graphite gaskets are preferred in refineries, petrochemicals , high pressure pipe and heat exchanger.

2. Soft Gasket

A "Soft Gasket" is a term used when referring to a gasket that is easily compressed under a low bolt load. They are used in a wide range of applications for both general-service and corrosive applications. Mainly, these gaskets are suitable for low, medium and high temperature ranges depending on the materials from which they are manufactured. As a rule of thumb, soft gaskets should be used only in Class 150# and 300# applications. When selecting a gasket for your application, there are three main things to consider: pressure, temperature and media. Gasket manufacturers provide pressure-versus-temperature (PxT) charts for soft gasket materials. These charts allow one to determine if the material is suitable for a particular application and give a safe-to-use or not-safe-to-use criteria. With soft gasket materials, the material’s maximum working pressure decreases  as the temperature of the application increases.

Soft gaskets are mainly made of :

• Compressed Non Asbestos Fibre (CNAF) Grades.
• Graphite laminates – Stainless Steel Tanged and Reinforced Graphite.
• High Temperature gasket materials and laminates.
• PTFE & Filled PTFE. 
• All types of Rubber including Commercial, EPDM, Neoprene, Nitrile & Viton

Soft gaskets are used in a wide range of applications from pipe flange, heat exchanger, compressor and bonnet valve gaskets. Similar to regular gasket, it materials in used are different with the area of application.