Electrical heating apparatus

Electrical heating apparatus for automatically heating water passing therethrough from a cold water supply pipe to a hot water delivery pipe, comprising:

• a housing including an electrical heater therein;
• an electrical control device controlling said electrical heater;
• an inlet conduit connectable between the water supply pipe and the electrical heater for inletting cold water to the electrical heater;
• a heater coupling communicating with said inlet conduit for inletting water therefrom into said electrical heater;
• an outlet conduit connectable between the electrical heater and the water delivery pipe for outletting hot water thereto from the electrical heater;
• and a pressure-responsive device cooperable with said electrical control device to control the electrical heater and having an inlet communicating with said inlet conduit and heater coupling;
• characterized in that said pressure-responsive device senses the flow rate to or through the electrical heater to control the energization of said electrical heater in response to the sensed flow rate.

A regulating valve, comprising:

• a housing;
• a membrane within said housing;
• and a stem within said housing having a head of convex configuration facing said membrane but normally spaced therefrom to define a flow-control passageway;
• the convex configuration of said stem head producing, with said membrane, different cross-sectional areas and thereby different flow rates in said control passageway, creating differential pressures acting on said membrane tending to deform the membrane such as to maintain a relatively constant flow rate through the flow control passageway despite variations in water inlet pressure.