Steel Pipe Cement Mortar Vs Epoxy Lining
Steel Pipe Cement Mortar Vs Epoxy Lining
(OP)
Large diameter steel water pipe to convey raw water is specified to have cement mortar lining. Contractor wants to Use Solvent Free Epoxy lining instead. Client requires assurance that solvent free epoxy will give 50 year design life.
I am looking for a source of comparisons advantages, disadvantages etc.?
I am looking for a source of comparisons advantages, disadvantages etc.?





RE: Steel Pipe Cement Mortar Vs Epoxy Lining
Steve Wagner
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
There is not 50 years of service history to back up the use of epoxy coatings. A couple of rubber lined and epoxy lined installations have been problematic with reminders of the need for proven bonding and curing processes to ensure good adhesion. Otherwise there will soon or eventually be problems from outgassing and de-lamination. Good results and performance of epoxy fiberglass pipe does not translate to epoxy lining performance in steel pipe.
You probably have used or seen large diameter pipe products of Northwest Pipe Company. Almost all of their production receives lining and coating. Their website describes some of the options for linings and coatings. They probably could provide additional data for consideration of lining materials. The cement lining appears to be most commonly used for raw or potable waters, as mentioned by SteveWag. The epoxy or other linings seem to have benefits for corrosive / aggressive service. I would consider the epoxy linings to be useful for re-hab and protection of sewer pipe, like the products of the Insituform Co.
http://www.nwpipe.com/
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http://www.insituform.com/
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
In addition to what others have already said, I would only add that AWWA M11 notes that cement mortar lining provides some dependable extra ring stiffness to some otherwise quite flexible thicknesses sometimes used for steel pipes, whereas epoxy would not. If you decide to go with epoxy and a final service of the water is potable, you might want to check also (further to robsalv's post) that the material is certified for that use at the temperatures that will be involved in the project [I believe plastics and polymeric materials in general could be more subject to leaching behaviors at higher than normal/room testing temperatures].
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
My general conclusions are that epoxy lining will give a service life of 40 to 50 years before the onset of corrosion. Cement Mortar Lining in hard non aggressive water will give 70 years. In the UK where a lot of the conveyed water is soft epoxy lining has been used extensively but preference is now given to polyurethane linings which are more flexible and easier to apply.
Manufacturers are working at improving the flexibility and ease of application of 100 solids (solvent free) epoxy. Polyurethane may however be a better choice?
In the US epoxy is being used extensively and successfully to reline existing pipes to extend their service life by up to 40-50 years.
I still have not reached firm conclusions.
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
The life of cement mortar linings or epoxy linings could be impacted by changes taking place in the chemistry for purifying potable water. There was a recent article in the Flow Control magazine that described some testing of elastomers for effects of chloramination - the use of reduced levels of chlorine with addition of ammonia for longer residual effects.
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There might be liittle effect on the cement lining, or the epoxy lining might result in longer life, if the cement lining is deteriorated by chloramination. There certainly appears to be be definite effect on the elastomers in typical water piping system.
This would not effect a raw water system, if that is what you have to consider.
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
As far as cement-lining and chloramines for disinfection, I believe one of the very earliest utilities to use chloramines was reportedly Boston, MA in 1932. I believe Boston also is a quite prolific contemporary user of cement mortar linings, and incidentally just a very few years ago chose that very technology to rehabilitate with minimal disruption and for even longer life substantial sections of some major, unlined iron mains that were at the time in excess of 100 years old. As far as concerns of chloramination, I have incidentally also noticed that there have apparently been some concerns of chloramination that may be sort of opposite what you expressed (see effects on at least some sort of epoxy linings for at least small plumbing materials at http://waternet.com/article.asp?IndexID=6636816 ). I do not know if that “epoxy-lined” pipe tested is anything like what Bris is looking at.
While some rubber and other polymeric items have indeed likely been affected by disinfection practices (examples are thin plumbing items with which we are all likely some familiar, or have even “put our hands on”), it has been reported e.g. in Bonds R.W. (2004), Effect of Chloramines on Ductile-Iron Pipe Gaskets of Various Elastomer Compounds, Journal AWWA, vol. 96, 4, 153-160 that the configuration and quality of standardized, modern pipe gaskets per ANSI/AWWA Standard C111/A21.11 used with at least ductile iron pipe in the USA are reportedly quite unlike those items.
RE: Steel Pipe Cement Mortar Vs Epoxy Lining
I work for a polyurethane manufacturer who specializes in lining pipe spools. Our urethanes have been submerged for over 25 years with no chemical or bond break down. Our materials are ment for abrasive materials, not just water, so there may be a cheaper solution than ours. You will be looking for a MDI-PTMG (diisocyanate system) polyether polyurethane. DuPont/BASF/Dow may be good places to start.
check out our website if you have a chance:
www.irproducts.com
thanks Pete