HPAC Magazine

Why PVC Pipes Sometimes Fail And How To Prevent It

December 1, 2014   By BRANDON PEACH

Over the years, flexible PVC pipes have become more stable and reliable, achieving a rather low failure rate. However, there are still several ways they can be misused, with the user or installer typically to blame. Here are some do’s and don’ts in terms of installing, maintaining and storing PVC piping.

IMPROPER INSTALLATION

Do’s: Cut the pipe squarely and use the appropriate amount of cement to completely cover the end of the pipe so that there is a gapless bond between the pipe and its fitting. Take special care to use the correct solvent and applicator when you’re joining the pipe with its fitting. A proper solvent weld requires softening of the pipe and fitting–otherwise, fusion may not occur.

Don’ts: Do not use excessive amounts of cement on your PVC, which can result in failure due to improper fusion. On the other hand, when you do not use enough cement to cover an end of a pipe, voids between the pipe and fitting may occur. Rushing what might seem like a simple and straightforward process will only result in failure down the road.

IMPROPER MAINTENANCE

Do’s: If your PVC piping system will be buried, take the time to calculate the allowable burial depth and ensure that your PVC pipes won’t fail under pressure. Furthermore, develop a plan for dealing with pressure surges that are sure to occur over time. It’s critical that you take into account the environment to which the pipe will be exposed, including rocks, roots and aboveground traffic.

Don’ts: Do not subscribe to the philosophy of “bought, buried, and forgotten.” Ignoring air relief and surge control maintenance systems will result in a PVC piping system that won’t meet its anticipated service life. As with anything, proper care is proactive, not reactive. Rigid PVC is strong enough to endure some “abuse;” nevertheless, the absence of certain plasticizers limits its flexibility considerably.

STORAGE ABUSE

Do’s: Store in a dry, cool place away from the sun in a place that allows for proper ventilation. Duct tape the ends of the PVC piping so as to prevent vapor or water infiltration, taking care to use only enough duct tape to cover the openings. Store upright or on a level surface in order to prevent bending, which will negatively affect future installation.

Don’ts: Be careful when handling the PVC, as you don’t want to transport it unsafely or handle in such a way that it cracks or breaks. Do not use excessive duct tape – the solvents used to remove tape residue are often not PVC-friendly and may damage the piping. Finally, make sure that you don’t store it in a manner that allows for bending over time. A hard, clean and stable surface is vital to maintain the material’s integrity.

REPUTABLE SUPPLIER

Often, PVC failure comes down to how the PVC pipes have been handled, stored or transported. Although the material is extremely durable and can withstand myriad environmental factors, if not dealt with properly, PVC piping can be damaged. PVC pipes that have been stored outside in the sun, for instance, may lose molecular stability over time. Make sure to use a reputable flexible PVC supplier to avoid these failures. Common sense goes a long way when working with PVC – use it, along with these tips, and your storage, installation and maintenance will enjoy a long service life. <>

Brandon Peach is writing on behalf of Sylvin Technologies, a leading manufacturer of flexible PVC vinyl compounds. He also writes for EZSolution, a design, IT and marketing agency in Lancaster, PA. www.sylvin.com

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