Introduction to Valves - What is a Valve Car Seal?

Car seals are a simple device used to lock or 'seal' a valve in the open or closed position to prevent unauthorized operation of the valve.

Valve operation can only take place by cutting the seal, thereby giving evidence of either tampering, or activity by an authorized worker.

Car Seals are available in a choice of colours to suit your operational needs.

Colour coding of seals and tags is recommended to identify the valve safe position, e.g green for open and red for closed.

Other seal colours can be designated to indicate the medium flowing through the valve.

Car seals are used as part of a car seal program to seal valves in the open and closed position. Used in conjunction with a car seal tag in red or green to indicate the status of the valve. Generally used on process critical valves to prevent inadvertent or accidental operation of the valve.

Car Seals (CSC) on lever operated ball valves,
isolating a safety relief valve.

Car Seals options


Cable Diameter:

Cable Length:

Car Seals Colors:

Marking & Identification:


What does Car Seal Open, Car Seal Closed mean?

If your job is in anyway connected with pipeline processes, piping design or valve equipment supply, you may well have come across the terms Car Seal Open, Car Seal Closed, CSO, or CSC written on P&ID's (Piping & Instrumentation Diagrams).

Very simply, the terms describe to need to lock (seal) a valve to prevent operation either in the open or closed position. The device to achieve this is a Car Seal.

The term derives from a device used to seal the cargo on railway cars. Much like the seals you sometimes see on the back of container lorries. They provide evidence of any tampering with the contents of the car or container.