How To Make Threaded Pipe Connections On Pool Equipment
Most swimming pool equipment has female threaded ports that you connect to with male adapter threaded fittings. These threaded connections are the most likely place to develop a leak in your equipment, by far, and depending on the brand of equipment that you are installing you may need to make up to seven threaded connections just to connect your pump, filter and heater.
In addition to the potential for leaks upon installation, over tightening of the threaded port or use of the wrong thread sealant can actually crack the plastic casings of your pump, filter head or heater. Such a simple thing in theory, making threaded pipe connections, however if you are going to have a problem installing your own pool equipment then this is a very likely place to have a problem.
What NOT To Do When Making Threaded Connections To Pool Equipment
Stay off the dope! - The first mistake that you can make with a threaded connection is to use the wrong thread sealant. There are a host of different products used in the plumbing industry as thread sealants however many of these are not suitable for pool equipment since most pool equipment is made of plastic (ABS, PVC, CPVC etc). Any petroleum based thread sealants, such as pipe dope, are not acceptable for use on pool equipment. The petroleum based thread sealants will deteriorate the PVC and CPVC material over time. Additionally petroleum based thread sealants can expand as they age often times causing a failure of the manifold receiving the thread.
Over-tightening - A threaded pipe connection with an approved sealant does not need to be incredibly tight to be leak proof. As an installer you would aim to install the male fitting hand tight plus 1/4 turn with a leverage tool such as channel locks or a pipe wrench. Using a tool for threaded connections to a plastic manifold needs to be done carefully to avoid cracking the plastic.
Do not put any sealant around an active leak - If you have a leaking threaded connection, no amount of silicone or glue will stop that leak unless you open the system and rethread the connection with new thread sealant. Often this will require cutting into the PVC unless there is a union fitting that would allow you to reset the threaded port connection without cutting in. Thread sealants that create a bead such as silicone must be removed completely and new sealant applied. Compression sealants like thread sealant tape (teflon tape, gas tape) do not always need to be removed as sometimes you can give them an additional 1/4 turn and regain a leak free connection.
Do not use epoxy - Epoxy is not suitable for use as a thread sealant. Epoxy is permanent and a failure of the connection could require replacement of the entire unit since there will be no way to remove the epoxied connection or make a new water-tight connection.
Wrap the thread sealant tape in the correct direction - Thread sealant tape is designed to work in one direction with the idea that as you thread the connection into place, the thread tape will be pulled tighter into place. If you apply thread sealant tape backwards then it will have the tendency to unwind as you thread the fittings together and result in a leaking connection. In order to make a water-tight threaded connection with sealant tape you need to wrap the tape in the opposite direction that the male adapter will be turning. This causes the sealant tape to grab the fitting as opposed to being pushed off the threads as you tighten it.
The Best Thread Sealants For Connecting Pool Equipment
The industry standard for making threaded pipe connections with PVC and CPVC is thread sealant tape, often called teflon tape, plumbers tape, PTFE tape or polytetrafluoroethylene film. Not to be confused with gas tape, which is much thicker and usually brightly colored, as gas tape is too thick for the delicate PVC threads. A skilled hand can make gas tape work however the thinner teflon tape is ideal for the application. In the event a leak develops, a thread sealant tape can be tightened slightly more to become a water-tight connection once again.
100% waterproof silicone is a good choice for many threaded connections. This is the easiest way to ensure a water-tight seal on pool equipment however it is also the easiest thread sealant to fail and develop a leak. Once the silicone bead has set in the threads, any further movement of the threaded connection will break the seal and allow for a leak to develop. If this happens, unlike with thread sealant tape, you can not simply tighten the connection further. You must remove the threaded connection, clean it, and reapply silicone. Note that silicone caulk is NOT the same thing as 100% silicone and will not work as a thread sealant for pool equipment installations.
Lexel is an alternative to silicone with better adhesion properties, ability to stretch and can be applied in damp conditions - something that silicone very much can not do. This poly based rubber sealant is a great choice for repairs on existing swimming pool equipment where it may not be possible to make the area completely dry.
The pipe choice is only one part of the total equation when it comes to installing your pool equipment. Be sure to read all of the sections on how to install pool equipment to make sure you are using the right products.