Diaphragm accumulators are used in low flow-rate hydraulic systems to store pressurized hydraulic fluid and release it as needed in order to maintain steady pump flow and pressure, dampen vibration and shock, and compensate for leaks or thermal expansion. Diaphragm-type accumulators can also be used as a source of power in an emergency. They are completely sealed and can be mounted in any position. Typically smaller than bladder or piston accumulators, diaphragm accumulators have 8:1 compression ratio and are not repairable. They are most often used for mobile hydraulic applications where high shock and vibration are encountered, such as forestry equipment, agricultural machinery, and machine tools.