Honeywell D146M1040 Differential Pressure Regulator

Honeywell D146M1040 Differential Pressure Regulator. The differential pressure regulator eliminates excessive pump head pressure, when most radiator valves are closed due to reduced demand, by controlling flow through a bypass line when the difference between supply/return exceeds the setpoint. Install between supply and return sides of a hydronic system to stabilize pressure differential and reduce the effects of demand changes. Control maintains a constant differential between the two sides by opening a bypass whenever the difference between supply and return reaches the setpoint. Provides silent, trouble-free service. Easy installation; requires no electrical hookup. Easy adjustment of pressure by turning regulating cap. Built-in differential pressure indicator. Brass valve body with thermoplastic and stainless steel parts. Diaphragm of EPDM.