water leak

[dave reitman]

My pressurized hot/cold water system is made of pvc. When I put the threaded lines together in the spring, i notice a slight leak at some of the connections. Other than using teflon tape, what else can I use to stop the leaks. Remember I need to discconet the lines in the fall.

 

[Gord May]

Polybutylene (PB) Pipe?

DAVE:Does the leak seem to be originating from the joint threads, or perhaps the connection between the threaded fitting and the PVC pipe? There are several types of “Plastic Pipe”, and I suspect you may have “Polybutylene" (PB)- not PVC. PB has a history of failures (particularly /w “fittings”).Some plastic pipe materials:Polyvinyl Chloride (PVC)Crylonitrile-Butadiene-Styrene (ABS)Chlorinated Polyvinyl Chloride (CPVC)Polyethylene (PE)High Density Polyethylene (HDPE)Cross-Linked Polyethylene (PEX)Polybutylene (PB)Over time Polybutylene pipe will give leak and give trouble. There have been class action law suits against the manufacturers (ie: Cox vs Shell @ http://www.pbpipe.com/long_notice.pdf ).Remedies for repairing leaking Polybutylene (PB) piping systems have ranged from replacement of Acetal plastic with metal fittings or replacing damaged piping.Failure of the Acetal plastic insert fittings that were historically used as polybutylene pipe connectors, elbows, T-fittings, etc. The Acetal plastic insert fittings are usually gray and occasionally white in colour and are known to have leaked due to deterioration from chlorine exposure and from hairline cracking (due to over-tightening of fasteners) during installation. Given the problems with Acetal fittings, brass and copper fittings are commonly used today. Systems with metal fittings fail as well. However, it is true that systems with plastic fittings have more components that fail, and our experience tells us that they do indeed fail at a greater rate than systems with metal fittings or manifold-type systems. That said, both metal fitting systems and manifold systems contain polybutylene piping as well as plastic valves, and both of these components are subject to failure.In some cases, leaks are caused by improper installation of Polybutylene pipe in high temperature locations, such as locations too close to water heater or furnace flues, where it is not recommended for use. In addition, improper twisting/bending of Polybutylene pipe during installation can create stress on the Polybutylene pipe and connections, causing cracks and leakage.Inherent properties of Polybutylene pipe systems have also been identified as a potential source for leakage. Some published literature indicates that high levels of chlorine in the water supply may contribute to deterioration and potential leakage of Polybutylene pipe systems.Goto: http://161.58.169.127/articles/tecspk07.pdf for more information on PB Pipe: Hope this helps.Regards,Gord

 

[Gord May]

What I did /w my PB

I had PB pipe on my ‘84 C&C29, and experienced leaks @ two locations (HWT inlet & water pump connection).I inserted a galvanized nipple (4") between the PB pipe and the hot water tank, replacing the threaded fitting on PB pipe (/w crimp type). I replaced the Acetal threaded fitting on the water pump, with a crimp-on fitting. This required a special crimping tool, which I borrowed from a plumber friend.The “best” (though expensive) fix is to replace the entire plumbing system with “PEX” pipe & fittings. I didn’t bother on mine.Oh ya - I also installed a “TEE” Valve at the pressure water pump discharge. Normal position is straight through, /w “T” closed. Open “T” position and pump water, allowing water to drain into bilge. This removes vacuum lock, from pumping a “dry” tank. When you get “solid” water (no air), you close the “T” and continue pumping till you get solid water at a Lav. faucet.Regards,Gord

 

[Gord May]

What I did /w my PB

I had PB pipe on my ‘84 C&C29, and experienced leaks @ two locations (HWT inlet & water pump connection).I inserted a galvanized nipple (4") between the PB pipe and the hot water tank, replacing the threaded fitting on PB pipe (/w crimp type). I replaced the Acetal threaded fitting on the water pump, with a crimp-on fitting. This required a special crimping tool, which I borrowed from a plumber friend.The “best” (though expensive) fix is to replace the entire plumbing system with “PEX” pipe & fittings. I didn’t bother on mine.Oh ya - I also installed a “TEE” Valve at the pressure water pump discharge. Normal position is straight through, /w “T” closed. Open “T” position and pump water, allowing water to drain into bilge. This removes vacuum lock, from pumping a “dry” tank. When you get “solid” water (no air), you close the “T” and continue pumping till you get solid water at a Lav. faucet.Regards,Gord