Heat exchanger connection fitting complete with three-way valve uses differential pressure overflow valve between exchanger connections in fitting-parallel pipe permitting adjustable pressure setting

摘要

A differential pressure overflow relief valve integral to the fitting is arranged between the heat exchanger (25) connections (A,D), or alternatively a differential pressure indicator. The valve is set to a fixed or variable pressure, using valve seal spring loaded onto a seat in a connecting piece running parallel to the fitting outlet. Otherwise the seat on the parallel pipe valve is closed by a seal at adjustable spring force. The pressure indicator if used sits parallel to the fitting outlet and comprises a sightglass enclosing a spring-opposed piston. Valve and indicator can be combined and a regulating valve is sited in the path of the return connections (C,D) between exchanger and heat source (21).