IML – Intermediate Lock
Actuated valves in process operations are normally maintained in an energized state and may otherwise be part of a Distributed Control (DCS) managed system. During normal operations, valves will respond to process commands in a prescribed manner. However, during periods of planned maintenance, the command system managing the valves may need to be suspended to facilitate work tasks. In these circumstances, it is important to ensure that valves are set to their fail-safe position, and are disabled both remotely and locally, so that work may proceed safely.
SFC’s ‘IML’ lock is a mechanical device that interfaces between the actuator and it’s host valve. It uses an operating key facility to lock the actuator in the desired open or closed position so that the valve is prevented from turning. This key may be a part of an additional designed-in feature whereby the power source that energizes the valve can be interlocked with the IML unit itself to provide a total fail-safe solution by ensuring the power source and the actuator are mechanically interlocked and all functions are disabled.