Car seal open valve manufacturer ? 1

[AlexIgTec]

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 ?

 

[Montemayor]

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]

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]

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.

 

[BigInch]

Its just a couple of lugs with holes that a seal or lock will pass through and fix the valves position. A chain and a lock on a handwheel or around both the lever and the pipe can also be used.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[gerhardl]

There was earlier on the European market relatively complex stainless steel constructed mechanical interlocking devices for the offshore industry. Typical application: service valves beneath PSVs. (see above)

The construction was adapted to the ball valves (valve 1 and 2 (or more)) in such a way that the keysystem that fitted two or more valves was irremovable from the lock in certain positions, enforcing you to use the right sequence. I doubt you would find theese systems today, because of the small demand, weight and very high cost.

If you search for 'interlocking devices ball valves' you will indeed find the more simpel devices, which in my mind is equally safe,- as all devices will have a human factor involved - things could go wrong if yo do not know what you do.

 

[Ashereng]

"Car Seal" is a procedure. To operate a "Car Seal" valve entails some paperwork and procedure, per your company's policies.

A valve used in "Car Seal" service can be almost any valve. For most valves, you can add a locking mechanism onto the stem through which you can put the "Car Seal" (I think it is lead or tin or some other softish metal?), a lock, a chain, etc.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[JLSeagull]

Although real "rail car seals" are more secure, plastic wire wraps are sometimes used during startup where valves are tagged.

 

[bingopin]

Almost any valve can be carsealed open or closed. Where I work, a carseal proper is a plastic device usually threaded through the handwheel and yoke such that changing the state of the valve destroys the seal. We use two levels of carseals distinguished by different colors. A blue seal is typically referred to as an "operations" seal and is intended to prompt the process operator to understand that changing the state of the valve could have process or production impacts. Blue carseal valves can be operated at the discretion of the operator. Red carsealed valves are intended to require much more rigor in changing the valve position. It entails (as previously mentioned) strict procedures and paperwork and is used where changing the valve postion can create an overpressure situation or other "safety" issue. All block valves on either side of a process relief valve are red carsealed for obvious reasons. Red carsealed valves are indicated on the P&ID's and are audited on a frequent basis.

 

[pipehead]

Most new valves have a system whereby the valve can be locked or tie wraps. The manufacturers added these features in respoce to PSM and Lock, Tag, & Try rules.

 

[unclesyd]

As stated above CSO/CSC valves are sealed in either position with a seal that can be easily removed to operate the valve.

A LO/LC valve is a valve with a much more secure, cable and lock, that will require a key to operate the valve.

http://www.americancasting.com/cart/Scripts/visual_guide.asp

None of our relief valves on site have a block valve in the line. Where the valves have installed spares the switching from one to the other is accomplished with a bumpless 3 way valve.