PVC Repair - Further Reading

This Wiki page is a supplement to Swimming Pool Plumbing Repair in TFP Pool School. The Wiki provides additional detail on tools, products and methods for PVC Repair. All links to products and vendors are provided for the convenience of TFP Members and TFP receives no compensation from them.

Types of PVC

Sched 40 Sweep

Shopping for pool PVC parts can be confusing. Especially at the "big box' stores where they have PVC suitable for house plumbing mixed in with PVC suitable for pools. It is important to check the markings and select the correct PVC pipes and fittings for use in a pool.

Pool PVC (polyvinyl chloride) should be marked "Schedule 40". Schedule 40 PVC is made for water under pressure. If the pipe has ASTM D 1785 on the pipe, it's suitable for pressure applications. A rating of ASTM D 2665 means non pressure applications and should not be used for pools.

A pipe can be dual rated ASTM D 1785 and ASTM D 2665, but it has to say ASTM D 1785 if it's going to be used for pressure.

The pipe should also be labeled NSF-PW (National Sanitation Foundation - Potable Water) and Schedule 40 PVC.

You may also find Schedule 80 PVC in stores. Schedule 80 PVC is designed for higher pressure applications and can be used in place of Schedule 40 PVC.

PVC DWV Sweep

You will find PVC pipe and fittings marked DWV (Drain, Waste, Vent) in the plumbing areas of big box stores. DWV is for non-pressurized plumbing and should not be used for a pool. DWV PVC has thinner walls then Schedule 40 PVC.

You can visually tell the difference between pool rated Schedule 40 PVC and DWV PVC parts. Schedule 40 PVC parts have deeper hubs (ends) then DWV PVC parts. The shallower ends on DWV parts is the way to identify their incorrect use in pool plumbing.

You may also see CPVC products. Chlorinated polyvinyl chloride (CPVC) is a thermoplastic produced by chlorination of polyvinyl chloride (PVC) resin, which is significantly more flexible and can withstand higher temperatures than standard PVC. CPVC is sometimes used in pump unions. CPVC can withstand heat and can safely carry drinking water.

Cutting PVC

Cutting PVC is basically described in the Pool School article.

If you are working with 2" or larger PVC a Sawzall cuts it easily. They really do not sell a PVC cutter that works for larger PVC unless you pay a LOT of money for it. The $20 ones don't work at all.

A power miter saw or band saw is handy for cutting the new pieces to length if you have one.

Uncoupling Existing PVC Components

Using a Heat Gun if working with couplers

Rather than cutting out the exiting PVC plumbing a member devised a successful method of uncoupling the piece and just gluing on the new coupler:

1. Using a heat gun soften the PVC coupler in one spot and peel up and expose the male PVC pipe the coupler is glued to.
2. Then work the heat gun around while prying up the softened coupler all the way around until all coupler material is removed.
3. Using 80, 150, and 300 grit sandpaper sand the surface clean and ensure a proper fit for the new coupler.
4. Primer and glue the new coupler to the existing male PVC pipe.
5. Check for leaks.

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  Unpeeling union using heat gun

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  PVC after union peeled off

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  PVC after sanding

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  PVC with new union

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  PVC SWG connected

Stripped Screwholes in Valves

Sometimes this works, and sometimes it does not.

Take off the lid and set it aside. Then using two-part slow-setting epoxy, fill all the screws holes, and then before the epoxy sets up, dip the screw threads into Vaseline and screw them into the holes. Let dry overnight.

In theory, the screws should back right out. Clean up the lid area and make sure to replace the o-ring or seal.

Install the lid and make sure not to torque the screws to 100 foot lbs.

Gluing PVC

Follow the basic gluing instructions in the Pool School article.

Tips

• Use unions to connect to pumps, filters and SWG.
• Gluing PVC to CPVC you can use regular PVC glue if you give it 12 hours to set. Or you can use the Oatys red can All Purpose Cement.
• All brands have fast set glue types. There's nothing special about any brand. Faster setting glue is harder to work with. As long as you use good quality glue and give it plenty of time to dry, it's fine.
• While the Oaty website says “Can I use All Purpose Cement to join PVC to CPVC? No. It is not recommended because it takes longer for CPVC to finish the curing process necessary to complete a strong bond after the cement is applied. CPVC is also rated for hot water use which will affect cure times. PVC is not rated for hot water temperatures.” We feel that for pool uses it is acceptable.

Primers

Purple PVC primer chemically cleans the surface of the pipes. Primer also softens the pipe surface so they bond together tightly. Primer should be used before PVC cement.

Purple primer is only colored so inspectors or any one else can tell primer was used. If you are not very careful it can be messy looking. You can use clear primer.

Glues

Links for products the TFP members have used are provided for Members convenience.

• Red Hot PVC Cement has been used without primer.
• 10159 White 719 Extra Heavy-Bodied PVC Professional Industrial-Grade Cement Slow-Setting Low-Voc
• Oatey Cements & Primers
• Oatey® All Purpose Cement is a medium-bodied, milky-clear cement for use on all schedules and classes of ABS, PVC and CPVC pipe and fittings up to 6 diameter with interference fit.

PVC Parts Sources

Schedule 40 parts are hard to find in the home improvement stores. Below is a source members have found useful.

PVC Fittings Online has a TON of PVC parts you can't find at HD or Lowes and shipping is affordable. They have a lot of the hard to find stuff like a 2" 90 with a 1" tee.

Use of 90 Degree Sweeps

There is no real difference between a 90 degree elbow and a sweep 90 degrees. As long as you keep the water velocity below 6 ft/sec on the suction and below 8 ft/sec on the pressure side of the pump, the difference between a sweep 90 and sharp 90 is minimal.

• Size.......6 ft/sec......8 ft/sec.
• 1.5"...........38...............51 gpm
• 2"..............63...............84 gpm
• 2.5............90.............119 gpm
• 3.0".........138.............184 gpm

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