Definitions for "Pressure switch"
A switch that is activated at a specific pressure.
(Also called Pressure Cycling Switch) A pressure activated contact switch used to engage or disengage the compressor clutch. Usually they operate within a range where preset low and high pressures cause the clutch to disengage; mid range pressures allow the clutch to engage.
a device that connects between the pump and a storage or captive air tank
Keywords:  unsafe, psi, boiler, preset, coil
An adjustable safety device which prevents boiler operation when the system pressure falls below the preset level, usually 5 PSI. It helps prevent boiler coil and heat exchanger damage by preventing the boiler from firing during an unsafe low water pressure condition.
Keywords:  hobbs, adjustable, unit
an adjustable Hobbs unit
a device that senses changes in pressure and responds, according to its set point, with pressure fluctuations
A device used to indicate the flow of air or water through changes in pressure.