Car Seal
What is the function of Car seal?
In a process plant, some of block valves shall be put in a fix position for specific reason. For example, a drain block valve is Car seal Closed (CSC) to avoid loss of inventory in the event of inadvertently opening of this valve. This CSC valves can assist operator easily identify those valves position can only be altered with specific permission via stringent control procedure. Similarly, pressure relief valve inlet and outlet isolation valves are Car Sealed Open (CSO) to avoid operator inadvertently close.
How Car seal is implemented in a valve?
Nowadays, most (if not all) valve manufactures will have hole cut in valve handles and tabs on the valve bodies. Some valve manufactures will treat this as additional feature by providing a "add-on" adapter with in-built hole. These holes can be lined up and cable seal, plastic / metal strips, etc. Following are some images for different seal type.
Heavy Duty Bolt Lock
Can only be cut by special cutting tools...
Cable Seal
Plastic Seal
Car seal enhance safe operational of a plant. For safeguarding purpose, higher safety devices e.g. locked open; key interlocked, etc shall be used.
The important, function and implementation of Car Seal Open and Car Seal Close block valves has been briefly discussed in "How CSO and CSC helps ?". Nevertheless, as the car seal strip
• can be easily cut by any cutting tools except the heavy duty type which need special cutting tools
• may deteriorates after exposure to sunlight and severe whether condition
• needs to be replaced once it is cut and incurs additional cost it still invites question on the reliability & integrity of the security & safety and cost effectiveness of car seal strip. A key locked system increases the security & safety and cost effectiveness on long term basis as compare to car seal option.
The key will be kept in a cabinet in the control room. A strict procedure will be
In a process plant, some of block valves shall be put in a fix position for specific reason. For example, a drain block valve is Car seal Closed (CSC) to avoid loss of inventory in the event of inadvertently opening of this valve. This CSC valves can assist operator easily identify those valves position can only be altered with specific permission via stringent control procedure. Similarly, pressure relief valve inlet and outlet isolation valves are Car Sealed Open (CSO) to avoid operator inadvertently close.
How Car seal is implemented in a valve?
Nowadays, most (if not all) valve manufactures will have hole cut in valve handles and tabs on the valve bodies. Some valve manufactures will treat this as additional feature by providing a "add-on" adapter with in-built hole. These holes can be lined up and cable seal, plastic / metal strips, etc. Following are some images for different seal type.
Heavy Duty Bolt Lock
Can only be cut by special cutting tools...
Cable Seal
Plastic Seal
Car seal enhance safe operational of a plant. For safeguarding purpose, higher safety devices e.g. locked open; key interlocked, etc shall be used.
The important, function and implementation of Car Seal Open and Car Seal Close block valves has been briefly discussed in "How CSO and CSC helps ?". Nevertheless, as the car seal strip
• can be easily cut by any cutting tools except the heavy duty type which need special cutting tools
• may deteriorates after exposure to sunlight and severe whether condition
• needs to be replaced once it is cut and incurs additional cost it still invites question on the reliability & integrity of the security & safety and cost effectiveness of car seal strip. A key locked system increases the security & safety and cost effectiveness on long term basis as compare to car seal option.
The key will be kept in a cabinet in the control room. A strict procedure will be