Product

Spring-Return Actuator

Product Features
SUNTORK S series spring return electric valve actuators and tunnel damper valve actuator utilizes spring driven pinion and rack mechanism to provide torque ranges from 50N‧m to 260N‧m mechanical fail-safe quarter turn electric actuators. When power is supplied, the spring mechanism is compressed to store energy for movement. Once the power is lost or removed, the controlled valve or damper will be driven to fail safe position (either Fail OPEN or fail Closed) in either clock wise (CW, standard) or counter clock-wise (CCW, optional) rotation. In addition to standard open/close (two-position) control, floating and modulating control are available for option per application requirements. The open/close control is equipped with a buffer to reduce damages caused by water hammer which is resulting from sudden starting or stopping of flow. A clutch-less manual override is available option to provide manual operation when power outage, no clutch or brake is required to change from electrical control to manual operation.

一般

Product Features
SUNTORK explosion-proof electric spring return fail-safe actuators, in addition to normal function (floating control, two-position control, modulating control) are designed to provide fail-safe positioning of valves and dampers upon loss of voltage supply. A mechanical spring set is utilized to position the controlled device to either the fully OPEN or fully CLOSED position, without any external power source. For two-position type actuator, a mechanical BUFFER is employed at the end of the spring stroke, in order to reduce the dynamic effects of the spring return system. A clutch-less and lever-less manual override is optional for standard units to provide full-time manual positioning of the controlled device. The SE series explosion-proof spring return fail-safe actuator is structured as flame-proof and combustible dust-proof. The directive and standards marking is II2GD Ex db IIB T4 Gb, Ex tb IIIC T130°C Db. where it is classified as Zone 1 or Zone 2, containing Group IIA and Group IIB gases, Zone 21 or Zone 22, containing the combustible dust atmosphere or a mixture of explosive gas atmospheres and combustible dust atmospheres. Temperature group T1 to T4.