The V43/V243 Pressure Actuated Water  Regulating Valves are designed to regulate  water flow through the condenser of large  refrigerated cooling systems. These  pilot-operated valves open on an increase in  refrigerant head pressure and provide  modulating operation. The V43/V243 water regulating valves are  available for commercial and maritime  applications. V43 valves are available for non-corrosive  low- and medium-pressure refrigerants such  as R-134A, R-404A, R-502, and R-507.  Specially designed V43 valves are also  available for ammonia service (R-717). V243 valves are available for non-corrosive  high-pressure refrigerants such as R410A. Commercial V43/V243 valves are  constructed with a cast iron body, brass  internal parts, and bronze seat material. To resist the corrosive action of sea water, the  V43/V243 maritime and navy models are  constructed with a red brass body, bronze  and monel interior parts, and monel seat  material.