The internal metal check valves ensure that refrigerant flow is always directed through the desiccant regardless of the heating or cooling cycle

and that the blower is creating sufficient negative pressure to pull the valve diaphragm open

It matches all electrical and mechanical specifications

Does this part include the internal probes

including the popular S4A

Watts 0259705 Valve 320735-701 The internal metal check valvesThe Watts 0259705 is a high capacity 1 inch temperature and pressure relief valve engineered for commercial water heating systems and storage tanks. This Series 140X valve is designed to provide automatic protection against excessive thermal expansion and pressure spikes. Featuring a bronze body construction and an extension thermostat with a 6 inch probe, it ensures accurate sensing of tank temperatures up to 210F. The unit is ASME rated and CSA