R15 ‘Slow Open/Quick Close’ Valve Speed Control Unit The 515 Speed Controller is designed as an accessory to be specified for the use on all sizes of ESME R40 and R850 on-off valves, where there is a requirement for slow opening and quick closing of the valve, e.g. on oil fired boiler systems.
Opening speed for the on-off valve is adjustable by turning the unit’s air signal screw to vary the air inlet orifice size. The longest opening time of approx. 30 seconds occur when this screw is almost closed and the shortest time, approx 3 seconds, when it is fully open. On valves with larger actuators this shorter opening time may not be attained if the solenoid valve orifice is less than 0.125 inches, or if there are any similar air pipeline restrictions.
The very rapid main valve closing time of less than one second (with “close-on-air-failure” valves) is achieved by the quick exhausting of actuator air. As soon as the 3-way solenoid valve controlling the air signal is operated, pressure is removed from the top of the rubber diaphragm, which lifts to exhaust air through the annulus and ports shown. This closing speed is not adjustable and applies to all E.S.M.E. on-off valves fitted with 9″12″ or 15″ diameter actuators, regardless of solenoid orifice size. If required, an E.S.M.E. R188 ‘Failfix’ locking valve can also be specified to hold the main valve plug position in the event of air failure. Fitting this valve does not affect the slow open-quick close operation, and it is piped up so that even after air failure occurs, the solenoid can still be operated once to close the valve. On-off valves supplied with an R15 Speed Controller are fitted with a linear type valve plug, thus ensuring a smooth increase of flow throughout the main valve stroke.
VALVE OPENING TIME
Approx. 3 to 30 seconds (adjustable)
VALVE CLOSING TIME
Less than one second
30 p.s.I.g. (2.07 bars) normal
BODY AND CAP
Neoprene, Nylon Reinforced.