Providing Safety
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Sofis, previously known as Smith Flow Control, is an English producer of mechanical interlock systems for valves. These locks make sure that valves can only be opened or closed in a predetermined order.

Interlocking is a tested and trusted method for safe work based on exchanging coded keys.

Sofis is the first producer of the coded open-end wrench, which today is a much-used product in the industry. |

Our range of Sofis products consists of valve interlocks systems

Interlock for locking valves

Mechanical valve interlocks reduce the likelihood of accidents and regulate the behaviour of workers and contractors by eliminating the “human factor”.

Ritual and hazardous activities can only take place in a predetermined sequence, requiring compliance and prohibiting shortcuts that could endanger a plant, process, people and the environment.

Typical examples of applications include all types of valves (including engine and instrument valves), switches, vessel closures, access protection, pressure and temperature measurement systems, loading systems for rail, road and sea tankers, and any other application requiring process control.