CA1N4455E 09.2000 Siemens Building Technologies Landis & Staefa Division 4455 MXG461... MXF461... Modulating control valves PN16 with magnetic actuators MXG461... MXF461... with positioning control and position feedback for control of hot and chilled water systems Mixing or straight-through valves with magnetic actuators for modulating control of hot and chilled water systems in closed circuits. ?