thread378-447769 I need a method t

[A.I.H]

thread378-447769
I need a method to bulk dewatering for non pigable pipeline with length 3km

 

[1503-44]

Drain all water and push dry air or nitrogen through it until exiting humidity reading (ppm) is acceptable.

 

[LittleInch]

what can you get down the pipeline?

foam pig?

sphere?

How come someone didn't think of this BEFORE filling it with water?

Can you drain it at tall the low points??

you're going to need to give people a LOT more information to get anything other than flippant comments

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[A.I.H]

The pipeline length 3000m 8" and will branch to 4" and 6 " pipeline so it's not bigable.and the operating pressure is 30 bar.so the test medium must be water.
The question who I can remove the water after test.

 

[1503-44]

Since you can't run pigs, or "squeeges", it will be more difficult.

But maybe the same way you put the water in might work.
You will need some connections to pump the water in and to get it out.
Normally these is done via temporary headers connected to each end of the pipeline, which are removed just before welding the new pipe to the old. See here,

https://www.youtube.com/watch?v=lRFWeTRAcCU

Or you might be able to use some other kind of taps.
One connection to pump water in, located at the lowest point if possible.
You will need another connection, preferably at the high point, to vent air out.
Convention is to run pigs pushed by a dry gas, air or nitrogen, through the pipe and push out all the water, then continue doing that until the content is as dry as you need.
If that is not possible, you may be able to drain water out at the low point after finishing the test and then just blow dry gas through until pipe content is dry. How well or easy it will be to do that depends on how many high and low points there are and the pipe's drainage profile. Obviously having one uniform slope will be easier to drain than a profile with lots of ups and downs.

Has the pipe to be tested been welded to the other pipe yet, or can you still connect ends to test headers?
Can you post the elevation profile of the pipe to be tested?

 

[LittleInch]

AIH,

you're giving us about 10% f the information here.

What might be possible on flat or gently sloping pipeline won't work on pipeline with elevation changes so an profile would be very useful as well as a sketch of the system with any branches or changes in diameter.

Do you mean the pipeline starts at 8" then goes down to 6" and 4"?

Gravity can be your friend here but might need some taps in the pipeline

Or you can pressure test this in sections of the same size then weld together using "golden welds".

Have you looked up "gel pigs"? They basically squeeze down to different sizes and are commonly use don "unpiggbale" systems, e.g.

https://blog.aubingroup.com/evo-pig

As my friend mr 44 says, how are you filling this pipe? You need to eliminate 99% or more air from the system so how is this being done?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IFRs]

Why empty it? Can you drain-dry, fill it with product and seaparate out any remaining water at the other end?

 

[LittleInch]

/good point - For some reason I had assumed it was a gas pipeline but this is a valid way. /you just want to run at more than 1m/sec in any of the pipes and it's amazing how fast you will clear out the water

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

One reason might be that compressors don't like water slugs, but yes, we have a definite lack of information here. No service details, just 30Bar, no product name, no profile details. Gravity might be our friend, but could be the enemy. We can only take this as far as his/her words go and we already passed that point some time ago.

 

[1503-44]

LI, In your defense, it is somewhat reasonable to assume it is a gas pipeline simply because s/he thinks it needs to be dried. With no info, who can know for sure.

 

[LittleInch]

All he or she said was "bulk de-water"....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

OK, you are right. I was the one that said "dry". Consider yourself un-defended. So why then did you assume gas? This is where too many assumptions always take us.