Frequently Asked Questions
Q. "I purchased some 1/2" and 3/4" pipe, but I'm not sure how loose or tight they should be. How should I tighten the nuts on the couplings?"
A. Tighten until they squeak, and turn a 1/4 turn more. Don't over tighten, and you'll have a connection that will last trouble free for many years and can easily be taken apart and reused.
Q. "Can I use the above fittings to mix copper, PEX and Polybutylene pipe?"
A. The above Qest acetal fittings fit over copper, cpvc, PEX (crosslinked polyethylene) and Polybutylene pipe. They have a stainless crimp fitting and an acetal compression sleeve that fit over any of those pipes. You can have copper on one side and cpvc on the other side of the fitting, etc. They are very easy to use. They are more bulky than the old insert fittings and for tight places they might not fit or work.
Q. "I get confused about CPVC sizes. What type of CPVC pipe do these fittings fit?"
A. There are two "standard" sizes in CPVC, and this can be confusing. There is the size that matches the outside diameter of copper, which is called "CTS-sized". This is the type of CPVC that we offer, and that's the size that these QEST fittings will fit. With these fittings, you simply add 1/8" to the fitting size to determine the outside diameter of the pipe that will fit. (For instance, a 1/2" QEST fitting will fit CPVC pipe that has a 5/8" outside diameter.) PLEASE NOTE: The other type of CPVC pipe is the same size as steel pipe, which is known as "IPS-sized"; these QEST fittings will NOT compress onto IPS-sized pipe.
Q. "What does Nominal mean?"
A. "Nominal" refers to the inside diameter of the pipe, which varies by thickness of the pipe. The outside is a constant size and is always 1/8" larger than the nominal size. Example: 1/2" nominal is always 5/8" O.D. (Outside Diameter)
| Nominal Size To OD Size Conversion Table |
| O.D. Of Pipe |
Nominal Pipe Size |
| 1/4" |
1/8" |
| 3/8" |
1/4" |
| 1/2" |
3/8" |
| 5/8" |
1/2" |
| 7/8" |
3/4" |
| 1-1/8" |
1" |
| 1-3/8" |
1-1/4" |
| 1-5/8" |
1-1/2" |
| 2-1/8" |
2" |
Q. "How do crimp fittings work?"
A. Crimp fittings consist of two pieces: a male piece that fits inside the tubing and a crimp ring that fits over the tubing. A tool is used to crimp the ring onto the male fitting inside the tubing. This creates a permanent water/air tight seal with the tubing being captured between the two pieces.
Q. "Will your PEX crimp fittings work with my Polybutylene pipe?"
A. The crimp fittings we sell are made for use with plastic pipe that is Copper Tube Size (CTS), such as PEX. Since polybutylene has been discontinued since 1995, we cannot guarantee that these fittings will work on polybutylene pipe. If your pipe is CTS, these fittings may work, but we can only say for sure that these fittings will work on PEX and other CTS plastic pipe.
Q. "Can I use QickTite fittings to repair my hydronic heating piping?"
A. QickTite fittings are for use with basic residential plumbing. They are not designed for use with hydronic heating systems and they are not intended for use in recirculation systems of any kind.