Trapped-key interlocks offer enhanced safety and efficiency for the most difficult process management challenges. Mounted directly to valves, interlocks ensure a process only happens in the correct operational sequence.
Interlocks on handwheel-operated valves, usually require several full revolutions between the locked open and locked closed positions. After a period of use, the closed position on gate and globe valves may have altered. This can mean that when the valve is shut tight, the interlock (closed) key will not release as the valve has travelled past the original set key release position. Smith Flow Control’s (SFC) GL Interlocks can be adjusted in-situ in a matter of minutes simply by operating the valve back to the original key release position in two easy steps. Using the special tamperproof tool provided with the interlock, the interlock cover is removed and the setscrews are adjusted. Then the valve is operated again to its shut tight (closed) position and the screws are retightened (reset) in the new position.
This simple in-situ adjustment feature is unique to SFC’s GL interlock and provides a fast and efficient method of maintaining valve interlocks on site.