Two types of expansion joints can be found in mission critical applications: rubber and stainless steel. In general, expansion joints can be used in piping systems to provide stress relief, flexibility, movement in all directions, vibration control, and sound dampening. Expansion joints are commonly found on the suction and discharge side of pumps, at tank connections, in the middle of pipe runs to assist with thermal movement, and near building separations for seismic activity. Regarding mission critical applications specifically, rubber expansion joints are used in mechanical rooms mated to pumps and tanks, and stainless steel expansion joints are used in long runs of pipe to assist with thermal and seismic movement.
In general, the average life span of rubber expansion joints for most applications is seven to 10 years, while the life span of stainless-steel expansion joints is longer. Even with such long life spans, it's recommended by most manufacturers that consistent inspection, every six months to one year, be conducted on all expansion joints to ensure they are in proper working condition. Many manufacturers offer on-site support in the form of expansion joint surveys.