Pipe going underground 1

[Thomasjl]

Hi, I have to design 4 inch cold water pipe running above ground and going down under a bicycle path and then coming back up again. Can I just let it disappear into the ground or do I have to take special precautions? (apart from conservation) I appreciate your answer, Thomas.

 

[BobPE]

Thomas:

What part of the world will this main be in? Warm? Cold?

Also, is it a seasonal main or a full time main? What is the main used for?

BobPE

 

[pmover]

methods to prevent external pipe corrosion (some type of coating, FBE, tape wrap, etc.) may be highly recommended and applicable local, state, and federal design criteria for crossings MIGHT need to be addressed. depends upon location + other criteria.
-pmover

 

[pedarrin]

If you are using copper piping, usually (at least where I have seen it done) you would switch to type "K" tubing without any joints (Use the type that comes rolled.) This does not require any special fitting.

Keep the piping under the frost line.

Provide physical protection for the piping where it goes into the ground so any out of control bikes do not hit it.

 

[PVRV]

1. External Protection:

If applicable.

2. All joints to be tested. (i.e leave them exposed
during hydrostatic test)

3. Use of protective sleeve for road crossings. (i.e API-
1102.

4. Evaluation of external critical loads. (i.e RTRP AWWA
C950)

 

[murali2203]

provide at least 4" sand padding around the pipe in the under ground portion of the piping.

 

[BobPE]

sand?

 

[papatop]

Several of the suggestions were good but to answer question
about routing of a 4"cold water pipe is as follows:

1. Any exposed piping above ground should be insulated and shelled with an aluminized jacket to protect pipe and insulation from damage and deterioration. If piping is prone to freezing then heat tracing cable should be used.

2. Copper Type K piping is the best material to use for water distribution. Soft copper tubing sizes are up to 2" diameter. Hard copper comes in all sizes. All joints should be joined with silfos.

3. Provide a minimum 6" compacted sand bed in all directions of a buried pipe.

4. Last issue would be to make sure you provide proper pipe support intervals and stands as required by local codes.

4.Anytime a pipe is going to be suceptible to damage, protection should be provided such as using concrete filled steel pipes or long sections of angle iron partially buried into the ground and around the piping.

 

[BobPE]

Seriously, how can you say sand bedding and copper pipe? I would never put copper pipe exposed in an outside environment. I would never use sand bedding on a pipe I want to last more than a few months or years....

We need more information, so lets wait till we get it.....and not cunfuse people in the interim!!!

BobPE

 

[Hc168]

I am referring back to your reply to "Static Electric Discharge Hazards" - Piping & fluid mechanics engineering Forum, posted 04/07/04. In your reply, you indicated "Out the top my head the API 650 for storage tanks says that the entrance of vapour velocity should not exceed 7 m/s." I have a copy of API 650, and read the manual. I can't find the section or the page which refers to < 7 m/s. Could it be in some other API publication? I will be really appreciated if you can help me to locate the source of "entrance of vapour velocity should not exceed 7 m/s" Thank you in advance.

George H.C. Liang ---> e-mail: hc.liang@shawgrp.com

 

[OrangeDog70]

a bicycle path...above ground cold water line...doesn't sound all that complicated unless you left out some critical details....I'll make some assumptions...

Assuming bike path is non-motorized vehicles and is narrow and paved (or unpaved, doesn't matter), open cut the path and lay your coated steel or plastic pipe using 45 degree fittings. I will assume you don't need to go very deep with the line at this location...say about 3 feet from the crown of the bike path to the top of the water pipe. Cover the pipe with sand or smooth soil and cover and compact. Make the entry and exit locations in wide clearance of the bike path at least to the limits of the bike path easement. Recover the path to acceptable surface and you're done. If the path is in public property like a park or adjacent to a motorized roadway, you will need to check with the authority responsible for the maintenance of the path to get permitted for the crossing. I am assuming you have the right-of-way and easement to lay the line across the path.

You didn't mention much about having to protect the "cold" water line from freezing or maybe "sweating" in a humid climate. If you do, insulate. If you don't, don't worry about it.

Good luck.
Bob Lyons (OrangedDog70)

 

[dicksewerrat]

Don't use copper if it is exposed. It will grow legs and walk to the nearest scrap metal recycler.