5 replies to this topic

[fallah]

Dear all

I have a question: Must the line route between transferring pump(s) and burn pit have any specific conditions such as HPT(high point) , slope,....? and why?

Regards

[rxnarang]

My two cents worth....

It depends,

A high point in a liquid line is normally avoidable as it can cause a vapor lock. Sometimes, you want to break a liquid column, to prevent gravity flow emptying out the upstream vessel.

I would think that in your case as the pumps and the burn pit would be at grade, and the line would be routed over a pipe rack. So, avoiding a high point would be very difficult. And it should not be a worry, as the liquid column would overcome any vapor lock when the pump starts.

A common use of slope is for draining liquids in a vapor line, whcih should not be applicable in your case.

Does this help?

Rajiv

[fallah]

Dear Rajiv

Thanks a lot for your reply, but i am faced with min. two cases that the line toward Burn Pit has high point other than which due to routed over pipe rack,and i dont know its reason.Any help ?

Regards

[rxnarang]

Is one near the pump and the other near the burn pit?

My guess is that these are provided to avoid draining down the liquid either way; or to isolate the liquid in the pipe.

Do you have a sketch or something we can visualise? It is very difficult to look for a plausible cause for this design else.

My e-mail is rxnarang@gmail.com. Please feel free to write to me if you have anything interesting.

Regards
Rajiv

[JoeWong]

Is one near the pump and the other near the burn pit?

My guess is that these are provided to avoid draining down the liquid either way; or to isolate the liquid in the pipe.

Do you have a sketch or something we can visualise? It is very difficult to look for a plausible cause for this design else.

My e-mail is rxnarang@gmail.com. Please feel free to write to me if you have anything interesting.

Regards
Rajiv

Fallah,
I guess your question is not difficult. But i believe your question with insufficient neccesary information e.g. sketch, which high point you are referring to, etc. has resulted weak response.

rxnarang has made guesses and questions on his/her response. Please provide the necessary details for further advice.

[rxnarang]

Fallah,

Thank you for the additional information. It looks like the pump is at grade, while the burn pit is at +100 m elevation!! Is it on a top of a hill?

Anyway, with this configuration it is obvious why we have high points. As the line rises to 100 m the topography will not allow a smooth rise. The line will have high points simply because of the physical routing it needs.

Regards
Rajiv