FLUID POWER EQUIPMENT
TUTORIAL – ACCUMULATORS
This work covers part of outcome 2 of the Edexcel standard module:
APPLIED PNEUMATICS AND HYDRAULICS - H
The material needed for outcome 2 is very extensive so the tutorial is presented as a
• Identify and describe the features of given items of
pneumatic and hydraulic equipment.
Analyse the construction and
operation of pneumatic and
equipment and plant.
• Analyse the performance characteristics of given
items of pneumatic and hydraulic equipment.
The series of tutorials provides an extensive overview of fluid power for students at
all levels seeking a good knowledge of fluid power equipment.
On completion of this tutorial you should be able to do the following.
Explain the principles and symbols of accumulators.
Explain reasons for using accumulators.
Explain the purpose of back up gas bottles.
Explain the safety aspects involved with accumulators.
Describe the construction of different types of accumulators.
A hydraulic accumulator is a pressure vessel used for storing fluid. Accumulators are incorporated
into a hydraulic system for one or more of the following reasons:
to meet peak demands of power
to smooth out pressure surges
to provide emergency power sources.
To meet peak demands of power
In some systems a pump may be required to deliver a supply of fluid to affect a certain cycle.
However during this cycle the maximum demand might be required for 20% of the time so if a
pump is a fixed-displacement type the relief valve will be discharging most of the fluid for 80% of
the time. This represents a considerable loss of power if the pump is working continuously.
A smaller pump is used, so that during the slack period some of the fluid is used to charge an
accumulator. The charge is then used to meet the peak demands and substanti