review and summary

REVIEW AND SUMMARY

• An accumulator is basically a pressure storage reservoir in which a non- compressible hydraulic fluid is retained under pressure from an external source.

• Types of accumulators: The three basic types are:

1. Weight-loaded (or dead-weight) accumulators,

2. Spring-loaded accumulators, and

3. Gas-loaded accumulators.

(i) Non-separator type, and

(ii) Separator type.

(a) Piston type, (b) Diaphragm type, and (c) Bladder type.

• Applications of accumulators : The accumulator circuits are used as :

(i) Leakage compensator,

(ii) Auxiliary power source,

(iii) Emergency power source,

(iv) Hydraulic shock absorber,

(v) Fluid make-up device,

(vi) Holding device, and

(vii) Lubricant dispenser.

• In this chapter, the purpose, construction, and operation of various types of accumulators and accumulator circuits have been described in detail.

• Pressure intensifier, also known as presser booster, is a device which converts a large-volume, low-pressure fluid supply into a proportionately small-volume, high- pressure fluid outlet.

• Pressure intensifier finds its application at places where a liquid of very high pressure is to be developed from available low pressure. Typical applications include hydraulic presses, riveting machines, and spot-welders.

• At the end of the chapter, the purpose, construction, and operation of the pressure intensifier and intensifier circuits have been presented.

• Formulae Summary:

1. Sizing of accumulators :

For weight-loaded type accumulators:

Capacity = P × A  × L

For gas-loaded type accumulators:

2. For pressure intensifiers:

KEY TERMS ONE SHOULD REMEMBER

Accumulators

Weight-loaded type

Spring-loaded type

Gas-loaded type

Non-separator accumulators

Separator accumulators

Piston-type

Diaphragm type

Bladder type

Accumulator symbols

Accumulator circuits 

Sizing of accumulators 

Capacity of accumulators 

Intensifiers

Pressure boosters

Intensifier ratio

Intensifier circuits

Air-over-oil intensifier

circuits

Intensifier symbols