Choose a valve lock that’s fit for purpose

For most of my working life, I’ve been involved in finding ways to lock valves.

It’s often left me wondering why valve manufacturers have never applied some basic thought to the design of the valve to incorporate some feature that facilitates the application of a simple padlock or a more elaborate interlock device.

Whether the valve is being guarded against inadvertent operation e.g. a sprinkler system, or a far more critical process event like the isolation of a safety relief valve, it’s common that valves need to be locked.

Without such functionality integral to the valve design, operators adopt many types of after-market or retrofit systems.

Valves which operate with a wheel are simple locking problems to solve. A chain or a cable wrapped around the wheel rim or spokes, and again around something fixed nearby, another valve, some pipework and secured in place with a padlock.

Valves which turn through 90° via a lever or wrench are more problematic because the chain or cable can slide off the end of the lever negating the locking function.

I advocate that there is no valve in existence, which is operated manually, which cannot be locked. Whether that be by an existing after-market device or a bespoke, custom designed solution.

During my travels in Florida I came to notice outside almost every building on every street, is a valve installation. It’s not clear exactly what these valves are controlling; probably something to do with the water control to/from the building. Due to my somewhat curious interest in all things to do with locking valves, I always smile at the chains and padlocks that are applied. Given the easy access, public location of these valves, one can only assume this is to deter mischievous operation by passers-by. And this proves the point about using something that is fit for purpose. A robust steel chain and padlock are perfectly adequate to prevent this tampering. But would you apply the same solution to a pressure critical process on an offshore platform? Absolutely not.

In conclusion, when valves need to be locked, don’t be oversold. Find a solution that meets your functional requirements; it’ll usually fall within the expected budget.