Patent attributes
A tempering valve is connected to hot and cold water supplies. The tempering valve has first and second thermal valves, each of which mixes hot and cold water flows to produce a tempered flow at a selected temperature. the mixed flow from the first thermal valve bypasses through the second thermal valve. A small valve assembly is responsive to the flow rate therethrough. At low flow rates, direct hot and cold water flow paths to the second thermal valve are blocked. At or above a selected transition flow rate, the small valve assembly opens to permit direct hot and cold water flows from hot and cold water inlets to the second thermal valve. The tempering valve may include a failure protection valve which shuts off all flow in case of a cold water supply failure.