wait time for cpvc


Old 11-30-04, 01:22 PM
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wait time for cpvc

How long should you wait before turning on the water after installing some new cpvc pipe? I've seen figures from 15 minutes to 24 hours. Assuming normal temperature and low humidity.
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Old 11-30-04, 01:28 PM
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I try to go with the 15 minutes, but if I can wait longer I do. I have also turned it back on quicker but I know I am taking a chance on a leak. Good luck.
Old 11-30-04, 02:37 PM
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Over the years, a range of materials have been used to deliver potable water for industrial and residential uses. Early on, galvanized steel pipe was used for water distribution. This suffered from high cost of installation and internal corrosion, which after 30-40 years of use eventually constricts the water flow to the point of being ineffective.

For several decades now, copper tubing has been the mainstay and preferred method of water distribution inside residential structures, accounting for approximately 85% market share in new construction. When installed properly and when the water supply is non-acidic, copper plumbing has proven the test of time as a reliable and safe delivery vehicle for potable water.

However, in recent years, new materials have entered the market to challenge copper's dominance. PB, or Polybutylene tubing was popular for its low cost of installation compared to copper. However, excessive failures in the field led to class action lawsuits and the ultimate banning of PB in 1995. Over the years, a better substitute has emerged called CPVC, or chlorinated polyvinyl chloride. B.F. Goodrich (now called just "Goodrich") holds multiple patents on the resins, which it licenses to pipe manufacturers under the name FlowGuard GoldŽ. (As of June 2001, FlowGuard GoldŽ is now marketed under the Noveon name). CPVC is typically beige or light grey in color and is now approved by virtually every model building code for use in residential water distribution systems.

Compared to copper, CPVC appeals to some homebuilders due to its lightweight nature, ease of installation and lower overall installed cost. Often, these savings can be passed on to the consumer in terms of overall lower prices for homes.

However, as with any new material that challenges the proven performance of its predecessors, CPVC is not without its critics. Many professional plumbers avoid installing CPVC for fear of callbacks or lawsuits. With the PB scare still in recent memory, many do not understand the pros and cons of CPVC vs. copper plumbing, and therefore stay away for fear of the unknown.

This Tech Note is designed to demystify CPVC and help to educate consumers and professional under what conditions CPVC should be used, while pointing out the important considerations of both materials.

Benefits and Considerations of CPVC Plumbing Benefits of CPVC pipe include:

Resistance to corrosion and abrasion
Smooth bore for improved flow and reduces water noise
High impact strength
Easy, cost-effective installation
Competitively priced vs. copper
Lightweight reduces heavy lifting
Less subject to jobsite theft
Self-insulating to minimize thermal loss
Integral flame retardancy and low smoke density
Pressure rating of 100 PSI @ 180° F, 400 PSI at 73° F
Short-term pressure rating > 200 PSI
Flexibility virtually eliminates water hammer (no water hammer arrestors required under normal conditions)
Inert to acidic soils and corrosive water supplies
Can be buried directly under slabs with no chemical interaction with concrete
Eliminates pressure leaks at solder joints
Easy for DIY'ers
Virtually no sweating or condensation
Relative price stability over time
Can be pressure tested in 10 minutes
Considerations of CPVC pipe include:

Generally limited to 1/2" to 2" Copper Pipe Size
Some complaints of "plastic taste" in water
Fittings and pipe subject to cracking or damage on job site if dropped or stepped on
Solvents used to join fittings and pipe contain volatile organic compounds (VOCs) which are known pollutants and require proper ventilation during installation
Subject to melting during a fire (becomes viscous at 395° F)
High coefficient of expansivity (1 inch in 50 feet over 50-degree temperature change) (3.4x10-5 in/in/°F)
Inner CPVC pipe surface can support the growth of bacteria including legionellae pneumophilia (ref. A Comparison of the Colonization by Bacteria of Copper and Other Materials Commonly Used in Plumbing Systems with Special Reference to Legionella Pneumophila)
Due to ease of installation, CPVC is sometimes installed by less skilled labor, potentially resulting in more frequent incidence of improper workmanship.
Subject to cracking during earthquakes
Generally requires a 24-hour cure period before pressurizing with water
Old 12-01-04, 06:16 AM
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So a cure time of 24 hours... do they expect someone repairing a broken pipe to wait 24 hours before they turn their water back on?

Let me ask this then: what is the harm in turning on the water before 24 hours? Is it the water that will affect the joints or is it the pressure? In other words, maybe I could turn on the water after an hour to see if there are any leaks. Then if all is ok.. I'll turn off the water and release some pressure from the new lines. So I'm curious if it is the water or pressure that makes the difference. If it is the water... maybe I could wait 12 hours max... if it is pressure then I'll do what I stated above.
Old 12-01-04, 06:49 AM
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Water AND pressure would both play a part in a failing joint. Going back to my original post, if you followed directions when you installed the joints (used cleaner and glue properly) I do not believe the joint would leak after an hour. My opinion but based on what I have done myself. Good luck.
Old 12-01-04, 07:07 AM
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Warranty, Warranty, Warranty, thats what it's all about, failure to follow manufacture installation instructions will cause any warranty to become void.

If you had a leak in a wall do to a failed joint, i.e. pipe pulled from the socket, not crack, not broken and they was able to prove set time needed for the glued joint was the cause, well guess what, you got it, you foot the bill.

It's in black and white, clear as daylight.

I'm not saying you have to let it set that long, even I don't wait full cure time, but for a warranty to say valid, one must follow installation instructions.
Old 12-02-04, 03:00 PM
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Don't know about CPVC. But with PVC it depends on the glue you use. Regular clear cement with primer must be cured generally overnight. The so-called RedHot Blue glue specifies that it can be pressurized to 70 PSI in 1 hour; higher pressure requires longer cure.
Old 12-02-04, 05:15 PM
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Redhot glue has never been approved for code use where I'm at.

With CPVC if you use flowguard gold pipe you have to use there own glue called flowguard gold, if you don't this to can void there warranty.

I do know flow guard gold glue is a one step glue, meaning no primer needed.
Old 12-02-04, 06:22 PM
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Been working with PVC and CPVC for years, using your standard purple primer and pvc/cpvc glue, never waited 24 hours, often I don't even wait 10 minutes.. Never had a leak. If you can't twist the pipe off, chances are water pressure won't either. The best advice is to clean the pipe and get the burs off, prime fully and allow the primer to dry (usually 10-15 seconds) and then apply the glue, but don't glob it on. Once you've twisted the pipes together (twisting helps ensure the glue is spread evenly), wipe off any excess.

If you are at all concerned about water pressure, install a whole house pressure regulator and set it for around 40-50 psi.

And remember, PVC for cold water ONLY, CPVC for cold or hot water.
Old 12-02-04, 08:28 PM
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Dunbar Plumber ; that was an excellent technote, I learned a lot from it . I hardly ever use cpvc as I prefer Pex, however that technote is going to get pasted in my workbook in case I have to deal with it sometime.
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