Threaded PVC joints
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:
- Clean out any old Teflon tape or silicone and thread the element or fitting back into the bushing to slightly open the crack.
- Apply primer and glue and remove the fitting to allow the crack to close.
- Attach a pipe/gear clamp around the bushing to prevent the crack from reopening.
- 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:
- Cut a new, matching lock ring in half.
- Place the two pieces around the pipe and use the appropriate glue to re-attach the halves.
- 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.
