Compression is the key to making gaskets work. The stronger the compression, the better the gasket works. Not having enough pressure on the seal makes it slide around or open up for contaminants to pass through. This is because gaskets are designed primarily to fit between mated parts of the machine – it is compressed between two objects, filling the minute spaces in between and creating a seal that stops liquid, gases and dirt from entering the machine components.
Materials often used in gasket making are the following: paper, silicone, fiber glass, metal, rubber, plastic polymer and felt. Some gaskets even contain asbestos should their specific application calls for it. Because different kinds of gaskets can be made of different materials, the manufacturing process for each type also differs. Primarily, the processes involve making a cut out of the material in its proper shape (the cutting procedure varies depending on the material, of course).
Manufacturers use a hot compression test to determine if a particular gasket can withstand tremendous pressure. This type of test applies both to the constant temperature and temperature on the gasket. How does it work? The compression set of the seal is measured. This determines the stress or creep relaxation resistance and reserve of the gasket. The manufacturer will then know if the gasket can withstand the tremendous pressure applied to it.
Gaskets have many industrial applications, including compression pressure of up to 2,000 pounds per square inch (and even higher). It is generally believed that the stronger the compressive load applied to a gasket, the longer the gasket will last.
When shopping around for a gasket, your first consideration should be its application. You may check the manufacturers’ websites and even product packaging for results of testing, such as the hot compression test.
