AlexIgTec (Industrial) 28 Mar 07 9:51
I'm trying to find following material :
Ball valve - Class ANSI 150 - RF flanged ends - Full bore - 6"
Body : cast steel - ball : 316 - Seat : PTFE - Lever operated with car seal open & closed locking device

Do you know a manufacturer offers car seal open valve in his products range ?


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Montemayor (Chemical) 28 Mar 07 10:05

Alex:

As the term, "car seal open", is used in process plants, any valve can be catagorized under that description if it is sealed in the open position and kept that way.

Your statement seems to infer that there are valves that are specially made in the car seal open position. That, I believe, is not true.

Do you know what a car-sealed valve is?

AlexIgTec (Industrial) 28 Mar 07 10:35
I have seen thread about this valve type on this website..


""Posted by: djack77494 Sep 7 2005, 06:24 PM
MTV,
I think there is a misunderstanding of the situation. PSV's are often spared to allow testing of one PSV while a
second remains active. In this way, the safety of the system is not compromised by testing and/or
maintenance of the valves. However, it is imperative that both PSV's are never simultaneously out-of-service.
Since it is easy to defeat the PSV by closing a block valve on its inlet or outlet line, measures are required to
see that this is not inadvertently done. The most common safeguard is to car seal open all of the block valves
around all of the PSV's. When a particular valve is to be tested or maintained, it is necessary to cut the car
seal (normally a plastic close once/never open flat device) and this typically requires the permission of a
supervisor or someone aware of the consequences of this action. Immediately after the testing or
maintenance, the block valves are fully opened and car sealed in that position. Note: The car seals are on the
BLOCK valves and not on the PSV's. Sorry but I don't have any pictures of car seals.
Hope that helps,
Doug
Posted by: MTV Sep""

So, ""car seals means a seal that's placed on a device that's used to change position of a valve in such a way that the position of the valve cannot be changed without breaking the seal.""

I'm sure this type of valve exist, but I don't know where..

SeanB (Chemical) 28 Mar 07 10:54
Just for information, a car seal is typically just a thin metal band that prevents an operator from inadvertently opening or closing a valve. However, these bands are very easily broken and for that reason in our refinery we physically chain lock open or closed any valves that require it.