Gaskets and seals are both an integral part to pumping processes. Though, like everything, gaskets and seals are not indestructible. Both gaskets and seals are designed to be very durable and appropriately applicable under the conditions they are intended for, yet they are still quite susceptible to deterioration over time. The two general reasons for deterioration of a gasket or seal fall into the following two categories: mechanical extremes and chemical extremes.
Although at times overlooked, gaskets can fail due to mechanical causes. For example, a typical mechanical cause of failure is due to friction: “It doesn’t matter which kind of seal your pump uses, there is usually contact (friction) between the shaft and seal. The materials from all shaft seals always start to wear down because of the friction. The seal wears slower and has a longer lifetime when the material has less friction on the shaft.”1 Friction can be reduced by selecting the proper seal on a pump, yet gaskets are more frequently susceptible to chemical causes of deterioration rather than mechanical causes.
EMC has already written an article on the chemical reasons why gaskets fail, though, to summarize briefly: “Gasket degradation can be the result of a combination of factors such as oxygen, ozone, light, heat, humidity, oils, water, solvents, acids and vapors.”2 Extremes in environments will at some point in time cause some form of damage to a gasket. The greatest threats to a gasket’s integrity in any application tends to be caused by causticity, extreme temperatures and excessive pressure on the gasket3. Even if considerations of both mechanical and chemical hazards are taken, gaskets and seals are still quite susceptible to deterioration.
There are no guaranteed methods of preventing deterioration of gaskets and seals. Due to the inherent designs and applications of seals and gaskets on pumps, there cannot be any way to totally prevent any degree of deterioration. This is because the gasket or seal on the pump will experience some form of extreme, mechanically or chemically, in the course of its operation. Likewise, the best and only means of preventing a seal or gasket from deteriorating would be to properly install the gasket or seal on the desired pump (mechanical consideration), as well as being mindful of the environmental conditions around the pump (chemical consideration). Otherwise, it is highly advised to consult a pump’s user manual for more information on the appropriate gasket or seal to use on a given pump.