Pressure operated motor driven pump - is fed from main supply and has emergency supply in form of cistern with float valve

摘要

The pump is driven by a motor which is switched on when the air pressure falls in the closed tank (due to water being drawn off) and switched off again when the pressure returns to a prescribed level. The pump is fed from the main supply and has also an emergency supply in the form of a cistern with a float valve. (It is essential to maintain the flow of cooling water to a dentist's high speed drill). The closed tank and the pump and the necessary controls can be fitted into a cupboard, which could also, without difficulty, hold the emergency supply cistern.