A heat exchanger only works when both sides are flowing. Lose the cooling side and process temperatures climb, sometimes quicker than operators expect.

Fitting an Ajax flow switch to the cooling water side gives a simple, reliable flow failure alarm. It is a mechanical sensing principle with an electrical output, so it does not rely on clever electronics to tell you the water has stopped. For exchangers in classified areas, the XP ATEX flameproof version applies. Built in the UK by a company that has been protecting cooling circuits since the 1940s.