The term pressure switch will almost always conjure up the idea of a device which senses a pressure and gives an electrical output of some kind.
Well, you can also get a pressure switch which gives a pneumatic output.
Pneumatic Pressure Switch
This is a piloted three port, 2 position valve (3/2) with an adjustable set point. Available normally open or normally closed.
Suitable for a wide range of applications including those where electrical signals are not permitted, atex, explosion proof or intrinsically safe applications. Can also be used for pneumatic systems where introduction of electric controls would not be required otherwise.