Relief Valve and Safety Membrane Arrangement in Lieu of Surge Tank

This paper describes the writers' experience in using an impulse relief valve and safety membranes to replace a surge tank in a small hydropower station. When the load on the generator is rapidly reduced, (load rejection), the impulse relief valve will automatically operate due to the increase in water pressure, thus, releasing a certain quantity of water to reduce the effect of water hammer and ensure safety of the unit and the penstock; this is the main principle behind this arrangement. Although it may be satisfactory to use the safety membranes alone, their use in the present project provides an additional measure of safety. Since this device acts in response to a pressure rise in the penstock, the manufacture, operation, and maintenance are simple and convenient. Use of this device in lieu of a surge tank can be economically beneficial.