The switching device SG-A is used as differential pressure
switch in dual-line centralized lubrication system. When
the differtial pressure is 50 bar and/or 100 bar, it releases a
pulse for the reversion of the directional control valve or for
the monitoring of the system.
Switching pressure difference 50 or 100 bar
Working pressure 400 bar
The switching device SG-A with ram, enclosed consists of a housing with a metallically sealing piston, which is held in its
mid-position by means of two compression springs. Furthermore, it consists of a limit switch, which is fixed in its position
by means of a safety plate, on which these parts are fixed.
With lubricating cycle 1, lubricant is supplied to main line A.
Main lineB is relieved.Due to the pressure build-up in main
line A, the piston is deísplaced downwards against the
springiness of the lower compression spring. When the
differential pressure between the two main lines is approx.
50 bar and/or 100 bar, the contacts 1 and 2 are closed via
the piston at the limit switch. Due to this pulse, the 4/2-way
valve is reversed via the electric control of the system.
The reversion of the 4/2-way valve causes lubricating cycle
no. 2 to start, and lubricant is supplied to main line B while
main lineA is relieved.Due to the pressure build-up in main
line B, the piston is displaced upwards against the springliness
of the upper compression spring. When the pressure
difference between the two main lines is approx. 50
bar and/or 100 bar, the contacts 3 and 4 are closed via the
piston at the limit switch, and a new reversion process