TorkDrive – a torque limiting device which prevents valve damage
Published: 7 August 2014 - Marianne Evans
Smith Flow Control’s TorkDrive is a device which prevents manual valves from being damaged due to excessive torque application during valve operation. It can be customised to suit most manufacturer’s handwheel operated valves (Ball, Gear, Gate & Globe, etc) where valves require a torque monitoring of over 80Nm.
The device is set to a predetermined maximum torque and if, during the operation of the valve, the operating torque increases above the pre-set limit, the TorkDrive will slip, indicating an irregular valve condition. Following over-torque, the TorkDrive unit will automatically reset to the predetermined torque.
TorkDrive is a customisable add-on tool which minimises the risk associated with unavoidable plant/process shutdown and unnecessary repair costs through valve over-torque. It can be specified as a simple, standalone unit mounted on either the valve input handwheel or directly to the valve input shaft; or it can be used in conjunction with SFC’s EasiDrive portable valve actuator, a non-impacting, air driven power tool designed to simplify valve operations.
In most circumstances, manual adjustment of the power source (air or electric) restricts or limits the output torque and speed (RPM) of the EasiDrive. However, if the use of the portable actuator is not restricted to larger valves and is used on a wide range of valves with differing sizes and operating torques, the TorkDrive would be the ideal solution. TorkDrive limits or restricts the operator from applying excessive force and protects the valve and valve seat from the over-torque that could be generated via the tool.
Features of the TorkDrive include clutch plates that are controlled by a series of calibrated compression springs. Two spring set configurations are available: a low range TorkDrive unit offering a maximum torque output range between 80Nm – 280Nm and a high range unit offering 250Nm – 420Nm. Each unit is factory set before installation and the unit can be adjusted to suit the host equipment’s torque requirements using a calibrated setting scale within the body of the device. Each spring set is colour coded, ensuring that the correct torque range is always used.