Due to some design and operational requirements there are valves in processes that must be locked in either a closed or open position to prevent a process incident from occurring.  Often these incidents have the potential to be catastrophic in nature with a high likelihood to cause fatalities or major equiopment damage.  The management of these valves to assure they are in the right placement is a critical operational process that must be managed with rigour and discipline.  These valves often have purpose built interlocks on them, but many others use chains, locks and car seals to ensure they stay in the right position and their actuation is closely controlled.

As part of a robust management process these valve installations should be logged and field verified on a regular basis to ensure that they are in the right position and that nothing has changed.  Additionally, when a valve must be placed in it’s non-typical position, the change should also be logged as part of a rigorous management of change process and risk assessment procedure.  Then, when the need is past, the return of the valve to it's “normal” position must be logged and verified as well.

Finally, as part of regular operational and maintenance rounds there may be times that a numbered car seal could be found on the ground.  Sometimes these seals losen, fail and fall off.  An immediate follow-up through the car seal log book should be made and a notation made with the new car seal number replacing the lost one once it is installed and the correct position of the valve determined.

Too often the necessity of a car seal log is overlooked as part of a disciplined operational process, but it is critical in maintaining and assuring safe operations.  Once established, a biweekly or monthly verification of the car seal log is a relatively easy task to maintain, but one that helps assure safe operations.