HWE Concussion Relief Valves are designed to meet the reqirements of water undertakings for relieving the water hammer which is the main cause of bursts in pipe lines particularly in risng mains. Both the fixed and the variable pressure control type of valves are available. In the latter type the pressure is adjusted manualy. With the installation of these valves, the problemm of bursting of water mains is reduced to minimum as the Water Hammer is the main cause of it.