Armstrong International Water Heater — Constantemp
The central component of the Constantemp steam-water heater is the feed forward blending valve activated by a differential pressure sensing head.
An impulse line to the top of the valve’s differential sensing head comes from a connection to the cold water supply line. Blended water is sensed under the diaphragm through ports in the blending valve.
The proportioning action of the blending valve occurs as changes in the sensed pressure differential across the diaphragm are created by flow demand.
As demand for blended hot water increases, a drop in blended water pressure is sensed under the diaphragm. This pressure drop causes the stem in the blending valves to move downward, lining up the hot and cold water ports of the valve plug with the ports in the body of the blending valve.
This action automatically proportions the hot and cold water blend ratio to maintain the set temperature for all flow demands. Water is blended instantly and automatically, with virtually no lag in response to demand.