About Industrial Gaskets
Choosing the Right Gasket
Gaskets are materials that seal between two different surfaces, under compression to create a static seal. The sealing is a result of the compressive forces created by sufficient bold load, and also works to fill the imperfections on the mating surfaces to be sealed. At Industrial Gaskets we have a material to suit all your needs and a great sales team to assist you in choosing the best material for your application.
Key factors involved in choosing a suitable material for a given gasketing application include:
- Temperature – possibly the most important factor in choosing a gasket material. When higher temperatures at the gasketed joint need to be sealed, the potential choices are quickly eliminated. If the system operating temperatures approach a gasket materials max. continuous operating temperature threshold, the next best material should be chosen.
- Chemical compatibility to the media to be sealed against (including flushes and system cleanouts). There are many different fluids and gasses to seal against, and many different choices of gasket materials to seal against them.
- Pressure at the gasketed joint. The internal pressure of the fluid should be a determining factor in choosing a gasket sealing material. If severe cycling or pressures changes occur frequently, a more robust material may be required.
- Application – this includes all factors such as the number, grade and size of bolts to create compression and the surface areas of the sealed joint. For EMI gaskets, this includes the amount of emi and rfi shielding required.
Because pressure and temperature are so closely connected, it is often effective to consider them together by measuring Pressure x Temperature or PXT value. Review the specifications of the gasket material you are considering – if they are both near the max. continuous operating limits of the application, a more robust material should be used.
An important factor to consider in selecting materials for gaskets is that most testing for OEM products is conducted under laboratory conditions. Actual field environments must be considered before a recommendation for materials can be made.
Factors Affecting Gasket Performance
A gasket has one basic function: to create a positive seal between two relatively stationary parts. The gasket must do a number of different jobs well to function properly – first, create an initial seal; second, maintain the seal over a desired length of time; third, be easily removed and replaced. Varying degrees of success are dependent on how well the gasket does the following:
- Seals system fluid.
- Chemically resists the system fluid to prevent serious impairment of its physical properties.
- Deforms enough to flow into the imperfections on the gasket seating surfaces to provide intimate contact between the gasket and the sealing surfaces.
- Withstands system temperatures without serious impairments of its performance properties.
- Is resilient and creep resistant enough to maintain an adequate portion of the applied load.
- Has sufficient strength to resist crushing under the applied load, and maintain its integrity when being handled and installed.
- Does not contaminate the system fluid.
- Does not promote corrosion of the gasket seating surfaces.
- Is easily and cleanly removable at the time of replacement.
During the gasket product selection process that follows, we recommend that these nine (9) factors be used as a checklist from the viewpoint of the user’s degree of need for each factor and the manufacturer’s degree of compliance.
For more information, contact us today.