Answer & Solution
Answer: Option
D
Solution:
What is a Reciprocating Pump?
Imagine a pump that uses a piston (like in a car engine) to push fluid. That's basically a reciprocating pump. Because of this piston movement, the flow isn't constant; it goes in pulses.
What is an Air Vessel?
An air vessel is like a small tank filled with air, connected to the pipe near the pump.
Why do we need it?
Let's look at the options:
Option A: Smoothens the flow by avoiding pulsations
This is the correct answer.
Think of the air in the vessel as a cushion. When the pump pushes hard (during its stroke), some of the fluid goes into the air vessel, compressing the air. When the pump's push is weaker, the compressed air pushes the fluid *out* of the vessel. This helps to even out the flow, making it smoother and less jerky.
Option B: Increases the volumetric efficiency of the pump
Volumetric efficiency is about how much fluid the pump *actually* delivers compared to how much it *should* deliver theoretically. While smoother flow *can* indirectly help a little, it's not the main reason for the air vessel.
Option C: Saves the pump from the danger of cavitation
Cavitation is when bubbles form in the liquid due to low pressure and then collapse violently, damaging the pump. While air vessels can help *reduce* pressure fluctuations, they're not primarily designed to prevent cavitation. Other measures (like increasing the inlet pressure) are more important for that.
Option D: None of these
Since Option A is correct, this is wrong.
Therefore, the primary purpose of an air vessel in a reciprocating pump is to smooth out the flow and reduce pulsations.
