Surge Anticipator Safety Check Unit For A Liquid System

A surge anticipator safety check unit for use in a liquid system including a liquid distribution system and having a pump and piping downstream of the pump for distributing pumped liquid to the liquid distribution system, wherein the pump intakes a liquid at an intake pressure and outputs the liquid to the liquid distribution system at an output pressure which is greater than the intake pressure, and wherein absent action of the pump, liquid in the system exerts a surge pressure at the pump which is greater than the intake pressure, the surge anticipator safety check unit arranged intermediate the liquid distribution system and the pump and in liquid communication therewith and comprising:

• a liquid checking portion for checking liquid when back-flowing from the liquid distribution system toward the pump and having an inlet port in liquid communication with the pump, an outlet port in liquid communication with the liquid distribution system, an internal chamber intermediate the inlet port and the outlet port, and a check valve member disposed in the internal chamber for preventing back-flowing of the liquid;
• a surge anticipator portion, communicating directly with the internal chamber, configured to anticipate at least the occurrence of surges in the liquid distribution system relative to the liquid checking portion and to relieve liquid and reduce liquid pressure in the liquid distribution system when the liquid pressure in the internal chamber is at a pre-selected pressure which is greater than the output pressure of the pump or at a pre-selected pressure which is less than the output pressure of the pump;
• an air input portion, communicating directly with the internal chamber, and configured to provide air to the internal chamber of the liquid checking portion when the internal chamber is at least partially void of liquid and the pressure in the void is below atmospheric pressure;
• and
• an air release portion, communicating directly with the internal chamber, and configured to release air from the internal chamber of the liquid checking portion when liquid is in the internal chamber and air in the internal chamber is at a pressure above atmospheric pressure.