US Patent 10156382 Heat trap

An improved heat trap disposed in at least one of an inlet pipe and an outlet pipe for delivery of cold water into and hot water out of a water tank. The improved heat trap includes a tubular body and a seal element comprising first and second axially spaced flapper members which are adjoined by a spine. The seal element extends through the tubular body whereby the first and second flapper members form a seal against an interior surface of the tubular body to prevent the delivery of water through the tubular body.