The Sensor of Switches utilize Diaphragm-Piston Conbination, 500/18D Switches use Diaphragm Sensor can be suitable for neutral gas, lubricating oil,light fuel ect. Fluid medium. 505/18D Switches use no-leak piston sensor,can be fit for lubricating oil, light fuel such neutral lube medium. the Set Point is adjustable, and its adjustable range is from 0.5Mpa to 40Mpa.
505/18D mini diaphragm pressure switch