Many industrial processes require valves to be secured in a locked-open or locked-closed position. Netherlocks’ mechanical valve interlocks are designed to eliminate human error to ensure that critical valves are locked in the proper position. Standard interlocking products use a padlock and key, and provide no information about the current position of the valve. Netherlocks’ mechanical valve interlocks are operated with two colour-coded keys, which through a trapped key mechanism, control the open and closed position of a valve and communicate its current state. When the green key is released, the valve is locked in the “locked-open” position. For the red key to be released, the valve must be locked in the “locked-closed” position. If a valve is left in a midway position between open and closed, both keys are trapped in the device. Through this system, the current position of the valve is guaranteed. Netherlocks’ valve interlocks are fully mechanical with no need for electronic wiring. They are easily incorporated into new construction and are ideal for retrofitting older installations to mitigate potential safety issues, the company says.