On-site lock re-coding for valve interlocks

Smith Flow Control has introduced a new series of valve interlocks made of stainless steel. These products have on-site lock re-coding, which lets plant managers quickly adapt interlocking sequences to changes in process logic The new QLS and GLS interlocks provide a mechanical process management system for potentially hazardous valve operations requiring strict sequential control.

A new feature is on-site lock re-coding. This lets plant managers quickly adapt interlocking sequences to changes in process logic. Interlock process control systems are typically used to support “Permit to Work” procedures during safety relief valve changeover, pig trap loading and retrieval, and filter changeover.

These new safety devices can be integrated with most quarter-turn and multi-turn valves, up to 3 inch diameter, in ball, plug, gate, butterfly and globe formats.

Retro-fitting on operational plant is possible without shut-down, since the interlocks simply replace original hand wheels or levers. Designed for long-term operation in the harshest of onshore and offshore conditions, these interlocks are made from 316 grade, Duplex and SuperDuplex stainless steels.

The standard finish is a bright yellow polyester powder coat (to RAL1021) which has high visibility for locating control valves in difficult conditions. Operation is by cast stainless steel “coded cardâ€? keys which simply push in and pull out of anti-ingress and weather sealed apertures in the lock body. Lock mechanisms are totally maintenance-free.