water distribution pipe material
water distribution pipe material
(OP)
What pipe material is preferable to use for water transmission line Dia. range 10inch- 16 inch.
Ductile iron is costly,GRP(glass reinforced plastic) is less costly but I did not use before! Do you think GRP is acceptable .
Ductile iron is costly,GRP(glass reinforced plastic) is less costly but I did not use before! Do you think GRP is acceptable .





RE: water distribution pipe material
RE: water distribution pipe material
RE: water distribution pipe material
For GRP you need to consider the added cost of bedding and backfill material. Even so I am finding it less costly than DI and PVC.
Joint flexibility is less than DI (about one degree) so you may need to use more small angle bends than you would with DI or PVC.
I have concerns over fittings and am proposing to us DI for valve complexes.
RE: water distribution pipe material
RE: water distribution pipe material
The argument that iron pipes have been in service for 100 years is good but will not "hold water" with my client who is looking at the cost advantages of GRP. Even if I include for replacement costs of GRP at 50 years and discount back to a NPV (Net Present Value) GRP comes out cheaper.
A concern I do have is that the pipe is flexible and relies on the backfill for its strength. For pipes through open country this is not a problem. For pipe under roads with other services there is a possibility that future excavations adjacent to or above the GRP pipe will not be backfilled to the same specification as the design backfill leading to excessive deflection, joint leakage and perhaps pipe failure. The risk could be high in congested streets.
RE: water distribution pipe material
Do you need special adapters to go from GRP pipe to DI valves and fittings? How do you handle corrosion then, since you cannot bond the fitting to the pipe? Probably have to stick an anode on each DI fitting?
RE: water distribution pipe material
Sounds like you have been hypnotized by the salesman for flowtite...
Are you in Europe or Middle East? It seems that most of this type of pipe is installed overseas, not in the US.
it sounds like with the bedding and installation issues, you will have future maintenance costs - fixing the leaks caused by poor initial installation or by future excavation/backfill near the pipe. Also by trying to connect into this transmission line.
I'm not trying to convince you to use DIP, but have no experience with GRP. It is not widely used in the US for water applications. In fact, none of the agencies I have worked for even allow it. For example, the City of Phoenix standard allows asbestos-cement or ductile iron for all lines under 16". Over 16" it allows ductile iron or concrete pressure pipe. For any other type of pipe considered, designer would have to convince the city engineers to approve it.
RE: water distribution pipe material
GRP can be joined to DI via normal flanged joints or Dresser (Viking Johnson) type couplings.
If you need cathodic protection then you would provide it locally to the DI fittings. clearly you don't need to bond to the pipe. If corrosion is severe then I would tape wrap the fittings rather than apply cathodic protection. If very severe than stick to GRP fittings. Only the valves need be DI in which case stick on a sacrificial anode.
Brian
RE: water distribution pipe material
Petzatakis of Greece are probably your nearest manufacturer, don't know if they have a factory in North Africa.
Zambo
RE: water distribution pipe material
Brian
RE: water distribution pipe material
FRP has been used in many places for water distribution, primarily in the Middle east. In the US we have an unusual situation in that items carrying potable water must have NSF approval, and food must have FDA approval. NSF approval is for a poduct only is approved, not a generic resin system. Ironically the NSF has typically not approved polyester or vinyl ester resins due to the possibility of leaching out residual styrene. Epoxy is the standard resin used for potable water systems. Ironically however FDA approves epoxy, vinyl ester and polyesters for food service (even products that are mainly water).
Therefore it is imperative to know what is the approving body for the piping system. Is it a local standard, or do they also use the NSF / FDA system?
Joining of the piping can be adhesive bonded bell and spigot, butt and strap, flanged or elastomeric gasketed bell and spigot (with or without mechanical locking). In some services they will use a gasketed bell and spigot with an FRP overwrap.
RE: water distribution pipe material
are you working on The Great Man Made River. I was working at Sirte Oil Company, Marsa El Brega a few years ago - not far from one of the precast concrete pipe factories. We installed a GRP fire-fighting line in the oil terminal, at the time there was no GRP production so we imported from Ameron, The Netherlands. But I guess your project is so large they can (or have) set-up a manufacturing facility there.
Zambo
RE: water distribution pipe material
Some of the PCCP has suffered severe corrosion and hence there is also interest in alternative materials for the larger diameter pipes.
Brian
RE: water distribution pipe material
I have a problem with the 100 year DI performance history. I think it is a sales tactic, as the iron pipe produced 100 years ago was much thicker than what is being produced today. It's an apples to oranges comparison (yesteryears cast vs todays ductile). Besides, I doubt there are many 100 year old iron lines that have never had a corrosion failure.
Considering contemporary materials, my concerns are how to restrain fiberglass, and do they make fittings? I'm not certain if fiberglass is NSF approved for potable water either. From my experience, fiberglass has been used more for gravity sewer lines, and I would want to see a reference list of their waterline projects. On the other hand, plastics have been used for water for quite some time now (AWWA C900 for PVC was first printed in the 70's). Plastic fittings are also available and mechanical joint restraints are ready off-the-shelf.
I'm sure the pipe material debate will rage on, but I lean towards PVC.
RE: water distribution pipe material
RE: water distribution pipe material
I little or no mention of fusion welded heavy wall PE pipe.
I have become fascinated with this stuff.
Seems durable forever, flexible, easy to work with and tap into, many providers, etc.
Was on a project overseas where the stuff was being installed in solid coral rock to move all water on the site, salt water, potable, sewage, etc.
PUMPDESIGNER
RE: water distribution pipe material
for a small network it will be good, and for temporary network it is economical even.
RE: water distribution pipe material
10-12 bar seems to cover most of the water transmission stuff out there.
But why not for large networks?
Just curious because I know nothing about these systems.
Just to show how little I know: By my weak understanding at this point I would have to believe that HDPE is VASTLY superior to CI, C-900, and all others. Lower friction, pervious to corrosion,few or no fittings, any fittings are fusion welded anyway, less build up internally, and more.
There must be some weakness I am unaware of?
PUMPDESIGNER
RE: water distribution pipe material
The weakness of HDPE is you need the equipment to work on it.
Water systems have been burned in the past by HDPE when insert fittings were used. The fitting will break (most likely at 2 am Christmas morning) or the HPPE will break at the fitting. Repairs using the same type fitting become a hassle, sometimes the HDPE splits as the new fitting is inserted, or it is impossible to insert the fitting because the pipe is not round or maybe it shrank, preheating the HDPE with a torch requires skill, especially when in a ditch with water all around.
Sometimes that coil of Black pipe is not HDPE, poly butlelene? soft PVC?
To use the fusion Welded method requires the purchase or rental of the specialized cutting and heating equipment. The excavation to cut in a new tee is much larger to accommodate the equipment. The contractor has it easy, weld the pipe on top, then move into the ditch.
If you operate water system, you need to purchase the equipment because when a rock migrates next to the pipe (the contractor says he did not put that there) then wears a hole in it , the rental stores are not open, or have the equipment is rented to someone else.
Hydrae
RE: water distribution pipe material
In fact, HDPE will not hold roundness as well as others.
Lack of equipment is a problem too, although I find this less convincing because good equipment would be purchased if the customer perceived an advantage to switching to HDPE.
Poor quality of installation yes, good supervision by knowledgeable person is required. Installation error though is always there even with the others. I have seen operators out there with lead wool pounding the stuff into CI joints. C-900 I have seen not much but would suspect installation errors, hey, a fool can screw anything up.
PUMPDESIGNER