Water Hammer Protection

WATER HAMMER PHYSICAL PHENOMENA

The physical water hammer phenomenon and how it occurs when a pump failure, causing and solving the problem generally

0 → 1 Normal operating status of the pump, stationary flow and normal operation of the plant.

1 → 2 Immediately after stopping the pump.

3 → 4’ In case of a pump shut-down or after a power failure, the pump will stop immediately, but the water column continues to move the same due to its inertia of physical mass. This creates a vacuum behind the pump discharge outlet.

4 → 4’ → After a while, the water column stops and starts the reverse flow (back flow) and creates high level of back pressure highly accelerated by the considerable force of vacuum.

With classical solutions for problems only with uncontrolled closing of check valves, which can result in high deceleration at pump shutdown and create violent and dangerous water hammer that can destroy the pump and/or the valves. Furthermore it can even cause dangerous pipe bursts.

Conventional solutions for this problem offer surge vessels, equilibrating tanks, relief valves and suction lines around the pump or similar solutions. These are good but highly priced and inflexible systems. All these solutions make sense, but they are very pricey, require considerable planning, execution time and need frequent maintenance.

HYDROMAT offers its solutions based on check and relief valve combinations:

Butterfly tilting check valve or butterfly double offset valve equipped with gravity to close and gravity to open actuators.

Axial check and axial surge relief valve.

Combination between butterfly valve as a check valve and axial surge relief valve.

PUMP PROTECTION – CHARACTERISTIC PHASE OF PRESSURE MOVEMENT WHEN THE PUMP STOPS SUDDENLY – CHECK VALVE AND SURGE RELIEF VALVE OPERATING AUTOMATICALLY BY PILOT VALVE