15 replies to this topic

[Arsal]

Any Codes/API will allow to provide isolation valve between flare KOD and flare stack?Kindly give your Technical suggestion with references.

 

Thankyou

Edited by rao arsalan, 07 January 2015 - 05:40 PM.

[Bobby Strain]

Have you checked?

 

Bobby

[fallah]

rao arsalan,

 

No relevant code/standard will allow to do so...

[ColinR33]

Don't do it.

[Arsal]

Hi 

Thanks to all

Mr fallah,kindly explain why isolating valve not provided here if no codes describe or deny this isolation.

[Bobby Strain]

There is no reason to have a valve. So the discussion is really unnecessary.

 

Bobby

[fallah]

rao arsalan,

 

Please note to attached as a page from a valid reference (pressure safety design practices for refinery and chemical operations) in which even putting a check valve in process pressure relieving path is conditional and in PSV inlet/outlet lines and flare header as safety pressure relieving paths is prohibited. 

 

 

Attached Files

•  Check valve in process pressure relieving path.pdf   63.32KB   94 downloads

[Arsal]

Mr Bobby

I am describing you a Scenario that is,

We have two refinery no one is Fuel+ Lube refinery and second is only Fuel refinery of approx 54000 BPSD .So we have Two Flare KODs the outlet line of both KODs is connected with the flare stack and flare is common of both refineries.so once we made turnaround(Shuutdown) for one refinery then we should shutdown other refinery as well for blinding/deblinding of flare KOD to segregate the KOD with flare Stack.

I think you should clear now and you should said that discussion is necessary.

Edited by rao arsalan, 09 January 2015 - 04:41 AM.

[Bobby Strain]

Now, this makes a bit more sense. It is confusing when you post this as a student. So, what do you do when flare maintenance is necessary?

With proper care, isolation valves might be acceptable. It depends on your government regulations whether this is acceptable.

 

Bobby

[ColinR33]

Normally by code isolation valves are not allowed in relief systems, but if you absolutely have to do it to allow isolation of different facilities, make sure the valve is chain locked open and you have isolation procedures written with appropriate sign-offs to ensure that it is not inadvertently closed, and that it is properly locked closed when you do need to isolate the header, and re-opened and locked open prior top coming back on line. Also critical is to ensure that operations and maintenance personnel are aware of these procedures and trained to follow them. One facility I worked at did have the same situation you are describing and that is the way it was dealt with, but the preferred method is to avoid it altogether.

[bmsharad]

I think water seal is acceptable, if it serves your purpose you can install

[bmsharad]

I think water seal is acceptable, if it serves your purpose you can install

Sorry, since you have a KOD water seal is irrelevant, I take back my post

[Arsal]

Thanks to all.

[balatpl]

If valves are inevitable and if gate valves are planned, ensure they are not installed in vertical orientation.

This is because, possible corrosion of stem could cause gate to fall down and block the path while in operation.

 

Keep the gate valve in horizontal position

[Mach21]

i am having same encounter. an additional new facility is tied in to existing flare header. An isolation valve is needed for shut down and hook up job.  The isolation valve has to be ensure always chain locked and captured this procedure in operating manual.

[Karlos]

There are special blinds being used in flares headers, worldwide, with or without block valves, that one operator open or close, in less than 3 minutes for a 40",