Purpose and placement of air vessels in reciprocating pumps Identify where air vessels are installed and why, in a typical single-cylinder reciprocating pump. Choose the correct statement.

Concept

• Reciprocating pumps produce pulsating flow, causing large acceleration/retardation of fluid in suction and delivery lines.

Function of air vesselsAir vessels act as hydraulic flywheels, absorbing and supplying flow to smooth the discharge, thereby reducing acceleration head, friction losses, and power fluctuation.Best effectiveness is achieved when fitted close to the cylinder on both suction and delivery lines.

BenefitsReduced risk of separation/cavitation on suction, smaller pipe sizes, and lower power requirement.

Final AnswerThey are fitted to both suction and delivery pipes near the cylinder to smooth flow and reduce acceleration head losses.