Design Code for High Pressure Water Pipeline

[CDNPIPE75]

Hey folks, I know this topic has been brought up before in different contexts, but I have a project that is a 50 mile (80km) high pressure, fresh water pipeline that requires a minimum 600# flange rating, perhaps 900# due to transients. It's NPS30, carbon steel. We are using B31.4 as the Code of choice for the pipeline and B31.3 for the pump station. I am just wondering opinions on AWWA guidelines.....I come from a hydrocarbon background and am very comfortable with the ASME Codes and think B31.4 is appropriate, and the AWWA are general guidelines, but not really codes per se. It seems that a lot of municipalities would use AWWA guidelines for domestic water consumption and build their own standards around the guidelines, but not sure it is robust enough for a larger, higher pressure, cross country pipeline with a design life of >25 years. At the same time, looking for potential savings if alternate codes would work and yet be technically defendable for this type of service. Thanks for your opinions.

 

[robyengIT]

also : PCCP prestressed concrete cylinder pipe (Lined and/or Embedded) as per AWWA (ASTM) C301-304

 

[1503-44]

AWWA design covers PE, PVC, Concrete, Steel Pipe.

https://duckduckgo.com/?q=awwa+pipeline+design&t=brave&ia=web

Changing the world can be very difficult. I don't think you have thought this issue through entirely. It's going to be all upstream. Re-educating all involved won't be easy. Try to imagine the reverse situation. Someone coming up with, hey, let's build this oil/gas pipeline to AWWA specs. No problem, its a steel pipeline, right?

I would think that you will
Have material procurement and specification, cost and delivery time issues.
You will be overloaded constantly with material substitution requests, which you will be forced, one way or another , to approve, revise dwgs, material list, spec docs, etc. Excessive Revisions work with high probability for mistakes.
You will not find any contractors that want to build a water line to B31.4 except for oil and gas pipeline contractors.
Waterworks contractors will object to almost every requirements of ASME codes and you will wind up recinding most all B31.4 requirements anyway.
You will pay 4 to 6 times as much, or more, than for a typical AWWA pipeline.
You will get very tired of explaining why you are doing this. Make a YouTube video for easy referral to all that ask. (Earnings potential there.)

Each time you have a maintenance issue, you will go through the same issues above.

Theoretically, no reason you couldn't do it and, maybe it's just me, but I have the same feeling I always get when the police car has just flashed his lights and is waving me over to the side of the road.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

Interesting...

To be honest you've probably asked your question in the wrong forum as this one tends to be like you and mainly Oil and Gas people.

Try looking in the water treatment and distribution forum as they tend to be "water people".

Key issue for me is what is this that you're moving and why such a high pressure for only 50 miles.
"Fresh water" could be anything. If this is potable water then you're in world of pain trying to use B31.4, but if it's just "water" for non drinking use then B31.4 is probably as good as you're going to get for a long distance high pressure steel pipeline. It's amongst the lowest of the codes in terms of wall thickness. I've used it for high pressure water injection lines and simialr, but I come back to the issue of whether this is treated water for drinking or some other kind of water. Either which way, you can't really use bare Carbon steel so what are you using or lining the pipe with?

I've never used AWWA stuff, but the water guys seem to love them so I would take a good look at what they have to offier and most importantly talk to your client.

This doesn't look to me like a typical water pipeline due to the pressure, but they run v large diameter mains all over the world, but often concrete lined Ductile Iron or PE or similar.



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

 

[CDNPIPE75]

Thanks for the comments. The supply is for a mine site with a significant elevation gain, which is what's driving up the pressure. The service is basically well water with an LSI ~0.5 so slightly scaling, not very corrosive. The water is for industrial use, not potable.

 

[LittleInch]

Then I think you're not bad with B31.4 to be honest. Not sure how you deal with the corrosion issues, but that's up to you.

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

 

[CDNPIPE75]

Indeed.....I don't have a good, working knowledge of the AWWA standards, but for such a high pressure I have confidence in B31.4 for sure......maybe B31.4 with some Code relaxations where it makes sense. Probably makes sense to go that way rather than using AWWA and having to bump things up in areas where AWWA may not provide guidance, or is insufficient. Thanks.

 

[1503-44]

You got me. 50 miles in a mine? I was sure (?) it was a municipal water supply line.
Yes, for a mine, use B31.4 We do the same for well injection water supplies.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."