Use of flanges in buried raw water pipeline
Use of flanges in buried raw water pipeline
(OP)
Hi
Does anyone have any experience in the use of flanged joints in a buried steel raw water pipeline? Is it a good idea? Has anyone done it? If so, what problems were found?
We are looking at 8km of 600NB pipe, with some above ground and some buried. The pipe has an internal epoxy coating, which would be easier to apply in 12m lengths, and quicker to install, as prefabrication is possible. This is a fast track project, hense the time concern. Cathodic protection and Denso wrap on outside. I'm not overly comfortable with the idea, due to maintenance concerns. Any thoughts?
Does anyone have any experience in the use of flanged joints in a buried steel raw water pipeline? Is it a good idea? Has anyone done it? If so, what problems were found?
We are looking at 8km of 600NB pipe, with some above ground and some buried. The pipe has an internal epoxy coating, which would be easier to apply in 12m lengths, and quicker to install, as prefabrication is possible. This is a fast track project, hense the time concern. Cathodic protection and Denso wrap on outside. I'm not overly comfortable with the idea, due to maintenance concerns. Any thoughts?





RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Use of flanges in buried raw water pipeline
On the other hand, a flange every 12 m will be the most expensive line ever laid. You didn't say what the design pressure of the line is, but I'll assume it is too high to use HDPE. It would be less expensive to weld the line and then pull a poly liner through it. They make those poly liners pretty long so you would only have a flange every couple of km or so (six flanges and a poly liner will be a small fraction of the cost of 700 flanges).
David
RE: Use of flanges in buried raw water pipeline
You can consider BigInch as one of the most authoritative members of Eng-tips and his advises are always valuable. Anyway, if I am not mistaken, you are still in a pre-project phase, and have to design a brand new pipeline. If so I wouldn't go for flanged connections.
http://books.google.it/books?
id=Ja28hvTxVpwC&pg=PA390&lpg=PA390&dq=water+and+wastewater+flange+buried&s
ource=bl&ots=wy0ios2tgW&sig=cRxVIYGftjGZjRLw1EptRTNOMpU&hl=it&ei=rPViS5S2C
s2gsQab2cnGAw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CA0Q6AEwAA#v=one
page&q=water%20and%20wastewater%20flange%20buried&f=true
RE: Use of flanges in buried raw water pipeline
**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Use of flanges in buried raw water pipeline
AWWA Manual M11, Steel Pipe – A Guide for Design and Installation, includes the guidance,
"The requirements of installation and operation of a pipeline may dictate the use of more than one type of field joint. The type of internal lining and pipe diameter will also determine factors in joint selection. Bell-and-spigot gasket joints cost the least on an installed-cost basis. Flanges are commonly used to join steel pipe to valves, meters, and other flanged accessories. Thermal stresses may be a consideration..." Under the headings of "Valve Connections" and " Flanged Connections" in this same manual, there are also some caveats for provision of flexible joints nearby, e.g. with the latter used at branch outlets, ""Outlet nozzles should be as short as possible to reduce the leverage of any bending force applied to the outlet. In general, every outlet should have a valve firmly attached to the mainline and a flexible connection to the pipe downstream from this valve."
RE: Use of flanges in buried raw water pipeline
Have you considered any of these ?
http://www.victaulic.com/content/default.htm
-MJC
RE: Use of flanges in buried raw water pipeline
If as I believe the original question was one of being able to join precoated pipe spools of approximately 12 m length, there are even better solutions out there that will actually allow you to buttweld the precoated spools without causing damage to the internal coating.
Check out the Tuboscope Thru-Kote system and their U.B. insert fittings and sleeve system. Both systems allow for butt welded joints while still providing for the integrity of the internal coating. Externally, you can easily coat the joints for external corrosion protection.
http://
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
Stephen Argles
Land & Marine
www.landandmarine.com
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
http://www.m-p.com/flange%20protector%20belts.htm
http://www.drakespec.com/flangeprotector.html
**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Use of flanges in buried raw water pipeline
As far as external coating for flanges, you are limited, they are all similar. I have been using Tapecoat H50 or H35 for a little added strength and mechanical resistance, I believe Denso makes a Densyl tape which is very similar you can use for added strangth over top, resists soil stresses better than just denso grease and wrap.
RE: Use of flanges in buried raw water pipeline
Have you ever seen overhead power lines induce a current on a pipe? I've heard of it forever, but with the regulator's resistance to new surface disturbance, I've run pipe in high-line right of way many times and have never seen a charge accumulation on the pipe (and I've looked). I've also never seen increased external corrosion on lines that do not have cathodic protection.
I'm thinking it is an Urban Legend unless someone has seen and measured it themselves.
David
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
David
RE: Use of flanges in buried raw water pipeline
RE: Use of flanges in buried raw water pipeline
http://ie
Here's another one for you. Don't store your pipe in the north-south direction.
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"The problem isn't working out the equation,
its finding the answer to the real question." BigInch
http://virtualpipeline.spaces.live.com/