Question

In a reciprocating pump, air vessels are used to

1. smoothen the flow
2. reduce suction head
3. increase delivery head
4. reduce acceleration head

Answer 1

Correct Answer - Option 4 : reduce acceleration head

Explanation:

• The air vessel, in a reciprocating pump, is a cast iron closed chamber having an opening at its base.
• These are fitted to the suction pipe and delivery pipe close to the cylinder of the pump.

The vessels are used for the following purposes,

• To get continuous supply of liquid at a uniform rate.
• To save the power required to drive the pump. This is due to the fact that by using air vessels, the acceleration and friction heads are reduced. Thus, the work is also reduced.

Note:
It may be noted that by fitting an air vessel to the reciprocating pump, the saving of work and subsequently the power is about 84.8 % in case of a single acting reciprocating pump and 39.2 % in case of double acting reciprocating pump.