There are four principal types of accumulators, the weight loaded piston type, diaphragm (or bladder) type, spring type and the hydro pneumatic piston type. The weight loaded piston type was used first but is much larger and heavier for its capacity than modern piston and bladder types. Both the weighted type and mechanical spring type are very seldom used today. The hydro-pneumatic piston types use a gas form to act as a spring cushion in conjunction with hydraulic fluid, the gas and fluid being separated by a thin diaphragm or a piston. 

A hydraulic accumulator is a device in which potential energy is stored in the form of a compressed gas or spring, or by a raised weight to be used to exert a force against a relatively incompressible fluid. They are used in fluid power systems to accumulate energy and to smooth out pulsations. Much as an air dome is used on pulsating piston or rotary pumps. They will cushion hydraulic hammer, reducing shocks caused by rapid operation or sudden starting and stopping of power cylinders in a hydraulic circuit.

A hydraulic system utilizing an accumulator can use a smaller fluid pump since the accumulator stores energy from the pump during low demand periods. This energy is available for instantaneous use, released upon demand at a rate many times greater than could be supplied by the pump alone.

Accumulators can also act as surge or pulsation absorbers, Quadco specializes in performing functional tests, repairs and/or replaces 4-way valves, chokes, and relief valves, as well as bladder recharge/replacement.