9 replies to this topic

[A mukherjee]

What is the difference between car seal open & lock open valve?
Regards,
Arpan

[A mukherjee]

How does CSO application vary from LO from process & mechanical point of view?

[breizh]

HI ,
Hope this resource can support you query :
http://www.google.co...ved=0CCIQ9QEwAg


Breizh

[A mukherjee]

Thnx Breizh for ur reply..
A more detailed answer will be appreciated.

[sheiko]

Another explanation is given there: http://webwormcpt.bl...-csc-helps.html
http://webwormcpt.bl...s-security.html

Edited by sheiko, 21 November 2010 - 10:24 AM.

[breizh]

Arpan
To me ,
No difference except that the carseal is a more sophisticated device but the function is the same :
lock the equipment in a position to ensure no wrong operation .

Breizh

[totallockout]

It's very simple. Both are methods to lock valves in the open position, but achieved with different devices.

The name 'car seal' derives from a device originally used on railway cars to seal the car shut (if it was carrying cargo) to give evidence of tampering with the contents and these are still used on road going cargo trucks and shipping containers today, especially when they pass through customs.

End of history lesson....

The car seal is a cable with a head on it. Usually a block of aluminum or steel. Where valves are concerned, the cable wraps around the handle or wheel, then around some other part of the valve or adjacent steel/pipe work. The cable is passed into the seal head. A screw with a break-off head tightens on the cable until the head shears off. This is now sealed. (There are other types on the market that don't use a shear of screw).

In the case of lock open, this can be achieved with a lockout device or valve interlock. The lockout device can be used in isolation on a single valve, secured in place with a padlock. The interlock will probably be used within a system of additional valves to not only lock the valve, but facilitate sequential operation of several valves.

Check out car seals here.

By the way, stating the obvious, you can also car-seal closed...

totallockout

[note]This is how you advertise your business in the forums without getting your posts deleted. Provide an extremely valuable and clear answer on the subject you know.[/note]

Edited by Chris Haslego, 23 January 2012 - 03:08 PM.

[shan]

It's very simple. Both are methods to lock valves in the open position, but achieved with different devices.

The name 'car seal' derives from a device originally used on railway cars to seal the car shut (if it was carrying cargo) to give evidence of tampering with the contents and these are still used on road going cargo trucks and shipping containers today, especially when they pass through customs.

End of history lesson....

The car seal is a cable with a head on it. Usually a block of aluminum or steel. Where valves are concerned, the cable wraps around the handle or wheel, then around some other part of the valve or adjacent steel/pipe work. The cable is passed into the seal head. A screw with a break-off head tightens on the cable until the head shears off. This is now sealed. (There are other types on the market that don't use a shear of screw).

In the case of lock open, this can be achieved with a lockout device or valve interlock. The lockout device can be used in isolation on a single valve, secured in place with a padlock. The interlock will probably be used within a system of additional valves to not only lock the valve, but facilitate sequential operation of several valves.

Check out car seals here.

By the way, stating the obvious, you can also car-seal closed...

totallockout

Hi Totallockout,

I like your explanation on LC/CSC. Could you explain how to interlock a control valve, which has no hand wheel, and a manual by-pass valve that has hand wheel?

Shan

Edited by shan, 24 August 2011 - 08:40 AM.

[totallockout]

Shan, sorry that you never received a reply before now....

If you have a control valve (with no manual operating device, i.e. wheel or lever) this means that the valve is probably 'controlled' by the plc (progammable logic control). I expect the valve is operated by a pneumatic or electrical actuator on demand of the control system.

If there is a manual bypass valve, this is usually to enable the flow process to be maintained, if the control valve is taken off-line for maintenance.

The bypass valve could be fitted with a mechanical interlock on wheel, but this should not be done without thorough review of the process to ensure that the process integrity is not compromised.

[Himanshu Sharma]

Adding my two cents !

mechanical interlocks are also applied in Flare PSV Isolation valve (equipment side) while using a 1 operating + 1 standby configuration of PSV.Here the intent is 'working' PSV shall be LO while the other one shall be closed.

Mechanical interlocks ensures that by any means both the valves are not Open or close,the interlock work in the fashion that if you close one isolation valve ,the other shall stay open and vice-versa.