PVC Repair - Further Reading

Types of PVC

Sched 40 Sweep

Schedule 40 PVC

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.[1]

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.

Schedule 80 PVC

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

PVC DWV Sweep

DWV PVC

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

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.

CPVC

CPVC is sometimes used in pump unions. CPVC can withstand heat and can safely carry drinking water.

Cutting PVC

Hacksaw

You can cut PVC pipe with a hacksaw.

Sawzall

A Sawzall cuts 2' PVC 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.

Miter or Band Saw

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

Masking Tape as a Cutting Guide

A piece of masking tape wrapped around as a guide to make sure you are cutting straight.

Uncoupling Existing PVC Components

Using a Heat Gun

Rather than cutting out the exiting PVC plumbing and joining new pieces as the coupler ends for the SWG are glued on, a member devised a successful method of uncoupling the piece and just gluing on the new coupler:[2]

  1. Using a heat gun soften the PVC coupler in one spot and peal 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.

PVC Reamer

Use a PVC reamer and ream out the old fitting.[3] This can be found under generic name of Socket Saver as a 2" Ram Bit.

Gluing PVC

Tips

  • Dry fit your PVC pipes after making your cuts.
  • Use primer and quality pvc cement.
  • After joining the pipes you must hold them together for 30 seconds until the plastic hardens or they can slip apart. It takes another 15 minutes for the joint to harden to a point at which it can withstand water pressure and two hours to fully cure.
  • 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.[4] 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.[5]
  • While the Oaty website[6] 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.[7]

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.[8]

Glues

Painting PVC

Prolonged exposure to UV rays (the sun) can degrade PVC and make it prone to cracking. In sunny climates PVC is often painted to protect it from UV degradation.[10]

PVC Parts Sources

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

PVC Fittings Online

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.[11]

Repair Tips

Temporary Hole Repair

If you ever need an emergency fix buy a coupling then cut down the middle. Then using PVC cement glue it on top of the hole and use a hose clamp until it dries.

Use of 2" Sweeps

Most sweeps are DWV pipe which has a narrower glue area. The view is sweeps are a waste of money and "space". The amount of head loss change is not going to be that much and the extra space they take up could end up requiring more bends. A sweep or 45 basically cuts the head loss of a 90 in half but the head loss of a single 90 isn't all that bad to begin with. A 2" 90 is worth about 6' of straight pipe.[12]

CPVC to PVC bonding

For pool use, regular pvc glue or cpvc glue works just fine as long as you give it plenty of time to dry. If it's a critical, high pressure application, then you probably can't join pvc to cpvc.[13]