5 replies to this topic

[Mohamed_Mamdouh]

Dear All,

I am looking into methodology to size pressure equalizing line (Pressurizing Line) across shutdown valve ?

 

Any hints or rule of thumbs that I could use ?

 

Also if there is an international standard I could use that would be helpful ?

 

I am thinking I might find a rule of thumb or a common practice table based on the valve size and the delta P ranges across the valve.

 

Thanks in advance for your help.

 

 

Regards,

M.A.

[christopherchoa]

I'm not sure about a standard out there that prescribes pressurisation line (but keen to know if there is one).

 

Usually DN200 or above, you want a DN50 pressurisation valve to prevent the huge valve from damaging its seal.

 

Cheers,

Chris

[Mohamed_Mamdouh]

I'm not sure about a standard out there that prescribes pressurisation line (but keen to know if there is one).

 

Usually DN200 or above, you want a DN50 pressurisation valve to prevent the huge valve from damaging its seal.

 

Cheers,

Chris

 

Do you have any specific criteria for sizing that line ? 

[latexman]

I would use Crane’s Technical Paper No. 410.

[Pilesar]

Determine the target time to equalize pressure then size the line to meet that time while keeping the line at least large enough so that it won't break if someone climbs on it. Unless the line is so small that it causes annoying delay, then no one will probably care what size you install. If a 2-inch line works, then just spec that and begin on the next task on your list.

[christopherchoa]

And watchout for JT effect.