Explain water hammer phenomenon and state the remedies measures to avoid it.

1 Answer

Answer :

Water hammer phenomenon: commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. Water hammer (or hydraulic shock) is the momentary increase in pressure inside a pipe caused by a sudden change of direction or velocity of the liquid in the pipe. Water hammer can be particularly dangerous because the increase in pressure can be severe enough to rupture a pipe or cause damage to equipment. 

Effects of water hammer are as follows

1) Due to rise in pressure the pipe may burst.

2) Erosion of inside surface of pipe.

3) Pressure drop in pipe

Remedies for water hammer:

1) Controlling Velocity of flow.

2) Use of appropriate length of pipe.

3) Elastic properties of pipes.

4) Provide surge tank before the valve on main pipe line.

5) Provide bypass pipe near the valve.

6).Provide Air traps or stand pipes (open at the top) to absorb the potentially damaging

forces. caused by the moving water.

7) Use high strength pipes.

8) Close the valve slowly.

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