Technical Index - Mechanical pressure switches

What is a mechanical pressure switch?

Mechanical pressure switches from SUCO monitor the pressure of liquid or gaseous media, and close or open an electrical circuit on reaching a set threshold.

Diaphragm pressure switches

SUCO diaphragm pressure switches are used in pressure ranges from 0.1 bar to 100 bar, meaning over pressure safety of 35, 100, 300 and 600 bar, depending on the used diaphragm type.

Piston pressure switches

Pressure ranges from 10 bar to 400 bar can be monitored with SUCO piston pressure switches (dependent on size); an over pressure safety of up to 600 bar can be attained.

Sizes of pressure switches

Mechanical pressure switches from SUCO can be divided into sizes hex 24, hex 27 and 30 A/F. Each particular size has specific hydraulic, pneumatic and electric properties (specified on the relevant catalogue page in the technical details).

How does a pressure switch work?

Function description for normally open (NO): Pressure is applied to the diaphragm / pistons through the pressure connector. If the generated pressure force is greater than the pre-tensioned force of the pressure spring, the plunger moves towards the counter-contact, carrying along the contact disc, and closes the circuit. The switch opens again when the pressure is reduced by the hysteresis value. Function description for normally closed (NC): Engaging happens in the reverse order. The adjustment screw enables the switching point to be changed within the adjustment range.

The micro switch of a change-over contact system (snap-action) offers both, a NC and a NO contact. The swivel contact is activated by the plunger. The circuit is closed by the NC as long as no pressure is applied. When the applied pressure exceeds the set switching point, the swivel contact changes over and closes the circuit via the NO.