reservoir piping Material 2

[CheckMate]

I am to install new piping within an existing potable water reservoir.

1. Is there a recommended material to use? I am not concerned with pressure or flow.
2. I am considering using Ductile Iron pipe. Is Ductile Iron pipe acceptable?
3. Is there any problems with material coatings during manufacture?
5. Should Ductile Iron or other type have a special cleaning that must be done, and should it be painted?
4. Do you have a manufacturer source that can help with these technical questions?

So many questions, is there only one answer?

 

[RWF7437]

D.I. pipe is widely used for potable water. No special cleaning is required, just ordinary care. D.I comes with a cement mortar lining. US Pipe and Ameron are large maufacturers of DI pipe in the US.

Good luck

 

[yogibear1]

DIP for potable use should be disinfected per AWWA C651-92. Most local Health Departments follow this criteria too. Many users also have high velocity flushing and/or pig their line before disinfection.

DIP for direct burial should be exterior coated with bitumastic, or if really corrosive soils it should be poly-wrapped; if aerial it can have shop applied primer compatible with your preferred coating system.

If you have general questions about DIP contact either DIPRA.org or ACIPCO.com. DIPRA is the Ductile Iron Pipe Research Association - they have area engineers (see their web site) that are very helpful and can provide all sorts of free techncial guidance and pamphlets. They even perform soil corrosivity analyses for you. ACIPCO is the American Cast Iron Pipe company out of Birmingham, Alabama. They have a very responsive network of area engineers which you can find on their web site.

 

[stanier]

You may like to take on board that in Europe 90% of pipelines are installed using themroplastic pipe such as PE, uPVC, MPVC, OPVC or ABS. Legacy materials such as DI do have a proven history however there are problems.

To produce DI requires significant amounts of energy and thus the thermoplastics are considered to provide environmental benefits.

negatove pressures from waterhammer can result in the ingress of contaminated water if the rubber ring joint is damaged. Who knows how long the rubber will last? Systems using PE or ABS can be fully fusion or chemically welded and provide a high level of system integrity.

Ductile iron suffers corrosion damage in sulfate soils or from stray electrical currents near railways etc.

 

[johnd43]

Noone seems to have picked up the word I read in the original post: "...new piping WITHIN an existing potable water reservoir". BOTH SURFACES of the pipe are going to be exposed to the product and therefore the external treatment must be suitable for immersion in drinking water, just as the internal surface should be. The answer is to challenge your supplier to provide certification of fitness for purpose.

I don't know your location but, if you are in any doubt about the manufacturing standards, you could go to uncoated stainless steel, but I wouldn't use 304 - use thin wall 316 and you should be fine. But note also the caution above about negative pressures - plastics and thin-wall stainless can be pulled flat very easily and they don't recover.

Immersed pipework can be a problem if it is going to be voided in the flooded reservoir - buoyancy, alignment and sectional stability and, again, watch out for the collapse risk. You might feel that the general stability issue favours a massive type of pipe such as Ductile Iron rather than a flimsy that must be supported at close centres to keep it straight. This will bring you back to the coating issue and your suppliers certification. UK and US authorities have standards for testing to provide the necessary assurances, and reputable suppliers will be able to work to a suitable standard.

John.

If I haven't left it better than I found it, I haven't tried hard enough.

 

[yogibear1]

johnd43 is right, my error for not reading the question closely. CheckMate did not say the pipe will be carrying potable water. Either way, DIP can still be used with the proper coatings. We would adhere to NSF-61 certification for all materials that come in contact with the water.

 

[dicksewerrat]

Look at using HDPE. Weight it down if it will operate empty. This material can have standard pipe fittings (flanges)welded on to convert to other pipes one you are out of the reservior.

 

[cvg]

standard welded steel pipe is used within tanks for potable water all the time. Pipe can be lined and coated to prevent corrosion.

 

[Ag93]

Go to

http://WwW.performancepipe.com

for helpful design information on HDPE pipe. We were formerly Driscopipe and Plexco. The site is a little confusing right now but try back later if it is too difficult to navigate.

I agree with all statements here, I would recommend that who ever does the fusion of the pipe be either trained by a HDPE distributor or have them do it for you. The fusion process is actually very forgiving but like everything, training is required. Good luck.