Safety shutoff system for steam cleaners and combination steam and water

Abstract

A safety shutoff system for steam and combination steam and water cleaners for permitting safe shutoff at the hand held spray gun thereof. The system includes a fluid reservoir connected to a first valve by a first conduit having a first pump for pumping fluid from the reservoir towards the first valve. A by-pass conduit connects the first valve to the fluid reservoir. An outlet conduit is connected to the first valve. The first valve controls fluid flow between the first conduit and the outlet conduit. The first valve blocks fluid flow from the first conduit into the outlet conduit upon detection of a pressure in the outlet conduit greater than a predetermined pressure such that fluid flowing from the first conduit passes into the by-pass conduit. The outlet conduit has a spray gun with a shutoff valve and a fluid heater between the first valve and the shutoff valve. A first switch detects the rate of fluid flow through the outlet conduit, and triggers deactivation of the heater when the rate of fluid flow through the outlet conduit between the first valve and the heater is less than a predetermined rate. A second switch detects the temperature of fluid in the outlet conduit between the heater and the shutoff valve, and triggers deactivation of the heater when the temperature of the fluid in the outlet conduit between the heater and the shutoff valve exceeds a predetermined temperature.