PVC plumbing repair

by Sally Bouorm | June 1, 2010 12:26 pm

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By John Duval

Hot tubs with multiple jets, limited access and numerous connections can make plumbing repair a major undertaking. Once the leak has been located, using the following tips will make hot tub (and even swimming pool) polyvinyl chloride (PVC) plumbing repairs much easier.

Keep in mind the more fittings, hose and pipe sizes technicians have on their trucks, the more options they will have in performing the repair.

Flex pipe repairs

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Before cutting the PVC flex hose, the first step is to determine which parts are involved in the repair and how they will be accessed. When a glued flex pipe joint leaks, the pipe should be removed rather than repaired, as this type of piping moves, making it difficult to glue in a new fitting. If there is room to cut it out, a drill bit for reaming plastic pipe can be used to bore out the existing fitting, leaving it clean and ready for solvent welding, allowing it to be reused while remaining in place.

The other option is to ‘dig’ out the old piece by using these steps:

1. Cut the flex pipe flush with the socket. Using a hacksaw blade, make four cuts inside the remaining piece of pipe at 12, three, six and nine o’clock positions.
2. Using a heat gun, apply heat to the inside of the pipe while holding a cool, damp cloth on the outside of the PVC fitting to prevent heat transfer.
3. Using needle-nose pliers, wedge the tip between the hose and fitting and twist the pieces out. Rather than gluing in another piece of flex pipe and adding a coupler, glue in a pipe extender or a 38-mm (1.5-in.) PVC pool adapter (spigot & barbed). The remaining end of the hose will now insert over the fitting. Apply glue and clamp.

Rigid pipe repair

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When a glued PVC joint has failed, simply reapply primer and glue instead of cutting out the pipe. Follow these steps to complete this repair:

1. With the hot tub and plumbing empty, tape over the jets and any other opening in the system.
2. Insert the suction hose of a vacuum into the other end of the plumbing—usually the union connection at the equipment pack.
3. Turn on the vacuum to create a partial vacuum in the plumbing.
4. Apply primer at the faulty joint and allow the vacuum to draw it in.
5. Apply PVC glue in the same area and simultaneously turn off the vacuum to prevent drawing the glue through the joint.

Caution: fumes from the glue and primer are flammable and explosive! Use this technique with extreme caution. Use an extended vacuum hose and do not place the vacuum indoors.

Threaded PVC joints

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Care must be taken when working with threaded PVC joints. These joints are tapered and over-tightening or using too much Teflon tape can crack the fitting. If there is time to let it set, try silicone, which will lubricate the fitting when it is being inserted and fill in any imperfections.

To avoid pushing the silicone into the plumbing and clogging the pumps and jets, always apply silicone to the male threads. To repair cracked PVC bushing, follow these steps:

1. Clean out any old Teflon tape or silicone and thread the element or fitting back into the bushing to slightly open the crack.
2. Apply primer and glue and remove the fitting to allow the crack to close.
3. Attach a pipe/gear clamp around the bushing to prevent the crack from reopening.
4. Reinstall the element or fitting with silicone and allow 24 hours to cure.

Note: Attaching a pipe/gear clamp before threading a fitting into a PVC bushing will prevent cracking.

Replacing and repairing broken union lock rings

Unlike a pipefitting, union lock rings are not tapered; they hold a union end to a pump or another union end. Over-tightening and shifting plumbing can cause the ring to crack.

To attach another ring, usually the plumbing needs to be cut to allow it to fit. However, two-piece lock rings can be used to replace standard 38 and 51 mm (1.5 and 2 in.) pump unions. These are similar to the two-piece manifold rings used on heaters, but are a different diameter to fit around PVC pipe.

In some cases, other union lock ring styles can be replaced by creating a custom two-piece ring. To create a custom two-piece ring, follow these steps:

1. Cut a new, matching lock ring in half.
2. Place the two pieces around the pipe and use the appropriate glue to re-attach the halves.
3. Tighten a gear clamp around the ring to secure.

Specialty PVC fittings

With a wide variety of fittings available, service technicians should be aware of the number of repair options now possible. These options include:

• Special PVC fittings: These include slip and spigot 45s, spigot elbows and tees and combination adapters and manifolds
• Pipe extenders: These glue inside a Schedule 40 pipe and leave a new spigot for reconnecting new fittings
• Inside pipe couplers: These are used to join two pieces of pipe if there is no space to glue a coupler over the pipe
• Fitting extenders: These can be glued over a Schedule 40 fitting, leaving a spigot end, and are ideal for PVC heater manifold repairs where all the fittings butt up to each other. To use, cut away the bad section, add the fitting and rebuild. There is no need to replace it.

Slide repair joiners

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These fittings use tapered sleeves, which slide onto the pipe and allow service technicians to perform a repair without the need to bend or flex any existing pipes. These joiners are available in sizes from 13 to 102 mm (0.5 to 4 in.) for proper fit to the existing pipe and fittings. They are ideal for repairing underground leaks in rigid pipe where there is no room to glue in a standard PVC coupler.

To use slide repair joiners, simply cut out the leaking section of pipe, then add glue to the joiner and extend the ends to ensure a permanent seal.

Repair glues and materials

There are many PVC, acrylonitrile-butadiene-styrene (ABS) and transitional glues available for making plumbing repairs; select the proper glue for the application. In addition to glue and primer, various repair materials are available. Some of the more popular materials include:
• Ground-up PVC: This material, when mixed with primer, forms a PVC paste for building up damaged fittings and other products.
• Liquid repair products: When poured into a hot tub, these blended concentrated materials sink to the lowest point to seek and seal minor leaks in a variety of materials. This product is good for sealing hairline cracks and holes up to 3.17 mm (0.125 in.) in diameter.

• Two-part compounds: These repair products comprise a liquid and powder compound. When combined they form a castable plastic that chemically fuses to PVC and ABS and cures in approximately 15 minutes.
• Two-part epoxy adhesives: These epoxies can be used to bond/repair a variety of materials. When using an adhesive dispensing system, the two-part epoxy can be easily applied to hard-to-reach areas.

 

John Duval is a technical service consultant with Central Spa & Pool Supply in Midland, Ont. He has been in the hot tub repair and technical service industry for more than eight years and is responsible for providing technical service for the company’s dealers. Duval can be reached via e-mail at jduval@centralspasupply.com[6].

Source URL: https://www.poolspamarketing.com/trade/pvc-plumbing-repair/

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