MEPCO Regulating Valve SWRF B combines the advantages of a spring-packed radiator valve with an adjustable regulating fitting. This valve is perfect for vacuum return line steam heating systems with pressures of 25″ Hg vacuum to 25 PSIG. It provides a positive “on” or “off” control with accurate proportioning of steam to a convector or radiator. When balancing steam distribution in a heating system, this valve eliminates the lengthy procedure of changing regulating plates (a process that requires the valve unions to be disconnected and then reconnected).