Hammering is caused due to pressure fluctuations in the lines. These fluctuations are caused when the flow is suddenly decreased or interrupted. Hammering can cause vibrations in the lines. It can cause pipes to burst, damage the pipe supports. It can rupture seals and cause leakage. Hammering should be immediately investigated. Water Hammering is also known as Hydraulic Shock.
Some of the causes of Hammering in pump lines are
Faulty pulsation damper in positive displacement pumps.
Operating the pump at the critical speed
malfunctioning of the check valves in the line
Some methods of minimizing hammering are
Reducing the velocity of the fluid.
Adding pressure absorbing devices such as accumulators or surge tanks.
Use of Pressure Relief Valves.
Using softstarters in motors which gradually increase the speed of the pump and provide a smoother rise in pressure.