Carseal Origins 1

[KenAlmon]

Does anyone know where the origin of the term "carseal" (whether it is one or two words is unknown) comes from? As in carsealing a valve open.

Thanks

Ken Almon

 

[Guidoo]

An explanation was given in thread378-8440

"Car seal comes from the rail car and freight industry. Once rail cars were filled, an inspector placed a metal wire on the loading valves. If the wire seal was broken, then the shipment could be refused. Each seal had a serial number or an imprint of the inspectors company. In the chemical industry it is an administrative control system to assure valves are not used inappropriately. For example, valves under relief valves are sealed open. This is better than chains and locks that used to be used in plants. If the valve is accessable by the public, like pipelines, then chains and locks are still used."

 

[donf]

This is only a guess. I suspect that "car" originally referred to a rail car - and "seal" describes a means to verify that the contents were not tampered with. (Just like the wax seals on letters). The difference between a carseal and a padlock is that the lock can be opened (picked) and relocked without any indication of such, whereas a carseal is "destroyed" the first time it's opened. Of course it would be dependent upon the seal not being able to be duplicated.

In the valve world, a carseal (or tamper tag) can indicate if the valve has been changed from it's required/normal/preferred position - but does not prevent (like a lock with no key) the valve from being switched in a legitimate situation.

Donf

 

[KenAlmon]

Thanks for the informative posts

 

[firstnerd]

Thanks for the above info on car seals. How is car-seal open different from car-seal closed? When is car seal closed used?

Thanks

 

[Montemayor]

firstnerd:

If you are a practicing Chemical Engineer, this is information you should have already absorbed or asked about in your plant environment.

This is basic-basic information about identifying and restricting those valves within a process that you must either mainain in the open position or in the closed position until otherwise approved to do the opposite - all in the interest of safety (99% of the time) and sometimes in the interest of product purity or operability (1% of the time). Out of curiousity, how is it that you have not been exposed to this operating principle? Just curious, for my education. This is a safety issue and I would like to know how we in industry can make it as well-known as is possible.

Art Montemayor
Spring, TX