These differential pressure controls are for use as operating controls and/or indicating system functions through display lights or panels. They measure the difference in pressure exerted upon its two sensing elements.
The controls are available for applications sensing air, oil or liquid. Typical applications are proof of flow across a chiller or water cooled condenser, proof of flow in a heating or cooling coil and lube oil pressure sensing on refrigeration compressors. On a proof of flow application the control measures pressure drop across two different points in either a closed water circulating system or a city water supply system.
On a proof of flow application in a water chiller system the control activates a light or signal to indicate a loss of water.