The Type 72 Relay features an adjustable bias pressure which enables users to obtain an output pressure which is the sum of a controlled input signal pressure plus the bias. Output pressure is accurately maintained under varying flow conditions by means of an aspirator tube, which adjusts the air supply valve opening in proportion to flow velocity. A balanced supply valve utilizing a rolling diaphragm makes the relay virtually immune to changes in supply pressure.
Simple design makes maintenance easy, and the relay virtually immune to changes in supply pressure.
Simple design makes maintenance easy, and the relay can be serviced without removing it from the line. Can be disassembled and serviced without removing from line. Operation Signal pressure in combination with the bias spring create a downward force on the upper diaphragm assembly. This force is balanced by the force of the output pressure acting on the lower control diaphragm. The output pressure then increases until force balance is achieved.