Compact Pressure Switch

Compact pressure switches are the simplest reliable way to signal that a pressure has crossed a threshold: oil pressure present, filter blocked, accumulator charged. There is no power supply and no electronics; a piston or diaphragm works against a spring and operates a snap-action contact.

The range covers 0.2 to 320 bar, with vacuum versions from −0.85 to −0.15 bar and a maximum working pressure of 350 bar. Contacts are normally open, normally closed or change-over (SPDT), with repeatability within 2 % of the setting range. The electrical connection is chosen to suit the machine: blade terminal, M12 × 1, Deutsch DT04-2P for mobile hydraulics, or a cable outlet. Wetted parts are galvanised steel or 303 stainless steel, and the temperature range is −20 to +100 °C depending on the seal material.

Accessories are mating connectors, protective caps and sealing rings for piston versions. The switches are used in hydraulics, pneumatics, mobile machinery, compressors and general machine building.

For process plant duty with higher temperatures, exotic materials or SIL requirements, see the diaphragm and Bourdon tube pressure switch; for adjustable set points with a display, the electronic pressure switch.