GRE Pipeline (Integral vs Section) Hydostatic Test

[MohdYaseen2010]

Our case as follow;
GRE (API 15LR) pipeline with 41 Km length & difference of elevation (141 m @ source, 13m @ 32KM from source, 22m @ 41KM).
Pipeline Design Pressure (DP) is 2MPa for the first 32KM & 3MPa for the rest 9KM.
The Contractor has execute hydrostatic pressure in sections (4 sections) & now they want to join these section WITHOUT CARRY-OUT AN INTEGERAL HYDROSTATIC PRESSURE as they will make some lamination (or banding) on the intended joints.
Contractor excusing with that no regulation/standard/code enforcing doing the test for the whole pipeline as one section.
Our main concern is for the lowest point (@ 32KM from source) as it will be subjected to the highest pressure (it has lower DP compered to the subsequent part).
Please give me your idea, and share any reference if you have?

Mohd Yaseen

 

[LittleInch]

Mohd,

Can you provide a profile and also explain why the last section, I presume this is the bit at 32 to 41 km, is a different design pressure. Makes no sense to me.

What design code are you working to?

Tyoing togehter sections tested separately is a common thing, but usually needs more than one type of NDT. This is difficult for GRE.

This really should have been thought about in the design phase and included in your specification / construction SOW.

Ask the contractor how he will test and ensure the quality of the connection in lieu of a hydrotest.





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[MohdYaseen2010]

Dear LittleInch;

Profile as per attachment. @ 32KM is the lowest point of the 2MPa section (the testing pressure will be governed by this 2MPa as design pressure for the whole pipeline). (Contractor procured another section of 3MPa cause of availability of material (with the same cost offered to the Client).

Design Code is API 15LR.

Tying different sections tested together is common (also to me) but with steel pipe as another NDT can substitute the need of testing the whole line, but in GRE the situation is different and new for me.

Contractor said they will use some lamination materials and add banding on the concerned joint, & observe the situation during the commissioning period.


Mohd Yaseen

 

[SJones]

API Spec 15LR is the manufacturing specification for the pipe, not the design code of the pipeline. Really should have been using ISO 14692-4 to cover hydrotest arrangements.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[HTURKAK]

What is the joining system; ( bell and spigot, double bell,butt and wrap..?) API 15LR scope covers the manuf. standards and factory tests rather than design..

Regarding design code , if American codes are applicable, you should look AWWA MANUAL M45 Fiberglass Pipe Design .

AWWA Manual M45 and ASTM D3839 standard do not include a recommended allowable leakage rate for GRP .That is, properly installed fiberglass pipes and joints should have no leakage.

I will suggest , keep open the joints at tying points of different test zones , and check the situation for leakage during commissioning . Repairing of The leaking joint is contractor's responsibility.

 

[LittleInch]

See this for options on ndt of gre

https://www.eng-tips.com/viewthread.cfm?qid=467295

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Also: If you get a response it's polite to respond to it.

 

[LittleInch]

Mohd,

I'm just curious as to what your max inlet pressure is at the top of the hill and whether you're keeping any back pressure, assuming your flow is from 0km to 40km direction?

With 130m elevation difference, your 20 bar pipe only gives you 7 bar max inlet pressure....

For those without GE the profile looks like this

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[Dhurjati Sen]

This is more of a management issue. What are the terms of contract with the contractor? Which codes and standards does she need to follow while executing the project? The client ought to have her own specifications amply laid down in the work order.

DHURJATI SEN
Kolkata, India

 

[MohdYaseen2010]

Dear All;

Thanks for your valuable inputs;

Dear SJones;
Yes the ISO 14692-4 is covering the requirements of this pipeline.

Dear HTURKAK;
Tie-in is done by threading (male/female), adding special adhesive, tightening, allow for curing time.
Your suggestion is what offered by the Contractor; but we don't accept cause the transporting medium is Oily water and leakage can't be allowed (environmental regulations).

Dear LittleInch,
Thanks for the shared page;
Yes (only max 7bar at source is allowed) this big design mistake; since we found this pipeline is designed without proper simulation (neither static nor dynamic) & this make a procured delivery pumps on the source are meaningless.

Dear Dhurjati Sen;
Actually, this not available, this what put us in this dilemma.

Mohd Yaseen

 

[SJones]

So, if ISO 14692-4 is applicable, what's the problem? Everything is covered if the contractor adheres to the standard.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[MohdYaseen2010]

Dear S Jones;

The issue is regarding the hydrostatic testing whether its acceptable in Sections Only & no need for integral pipeline or not? if sectioning is acceptable, then how we can confirm the joints between the sections? ISO 14692-4 doesn't specify those things!

Mohd Yaseen

 

[LittleInch]

Part 4 does give guidance on the various options for joints, quality control and testing.

For a laminated joint connection Appendix C3 provides a good requirement for such joints.

Alternatively you could maybe consider a collar arrangement where it is slid over th epipe and then glued at both ends then overwrapped maybe?

Sectioning is something that is generally allowed for practical purposes or for reasons of elevation, especially for gas pipelines.

14692 is really about piping rather than pipelines, so you really should look at the pipeline code used - or wasn't there one??

Either way I can't see why your contractor can't do a service test as part of commissioing when they fill it with water and just leave thos 4 locations open for inspoection

Given your elevation are they / you going to fill it from the far end?

Going to use a foam pig?

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