Plumbing notes

Threaded joints (NPT - national pipe thread)

(Wisdom from the ISM blog)

Dry fit (without any sealant) to finger tightness and mark the position. (I take a photo, can also mark the two parts with a sharpie line)
Remove and add thread sealant. Four turns of thin teflon, or some pipe dope
Retighten to dry fit positon
Wrench tighten 1.5 to 3 turns beyond.

Positioning elbows

Because of the range you have (1.5 to 3 wrench tighten turns) you have at least one full turn to adjust elbows. It mostly works. You can add thicker tape in cases where it doesn’t. Do not untighten. If you do, redo the whole thing with fresh tape.

PEX

(These are very brief notes. If you want to use PEX A or B in a project it is best to find current tutorials from manufacturer’s websites or YouTube)

There are two kinds of PEX: PEX A and PEX B. PEX A is connected using expansion and PEX B is connected using clamps. By-and-large they have similar characteristics once installed.

They are both UV sensitive and have to be stored and installed where they are not in the sun or other source of UV light.

PEX A

To connect PEX A you put a expansion ring over the end of the pipe and use an expansion tool to widen the end. You quickly slip the widened end over the PEX A fitting and wait for a bit. The pipe and the ring try to return to their original size and clamp tightly on to the fitting.

It’s not possible to dry fit the connections
(2025) A good quality powered expansion tool costs about $500
The contraction takes a little longer at colder temperatures.

PEX B

You slip a crimp or cinch ring over the cut end of the pipe and slip that on to the fitting. Then you use the tool to tighten the clamp over the pipe.

Crimping uses a solid copper ring. The tool compresses the copper into a smaller diameter.

Cinching uses an overlapping stainless steel band which is pulled tighter around the pipe using the tool.

The bands need to placed between 1/8” and 1/4” from the end of the pipe, which in turn must be cut square and placed flush against the fitting. The fittings have barbs on them and the compression ring must cover at least one of the barbs.

You can dry fit the pipe layout before finalizing the joints
(2025) A crimp tool costs about $100, a cinch tool about $30

Removing PEX B cinch clamps

Use a flathead screw driver to pry up the end of the strap. Then use pliers to peel off the strap from the three nubs that hold the ring together. The cinch clamp will spring open.

Removing PEX B from fittings

PEX B deforms after being clamped/cinched around a fitting. Even after removing a clamp the PEX B will remain in place. While it is possible to slit the PEX at the fitting with a utility knife and pull it off like that, it is a little dangerous and can damage the fitting. It is better to heat up the joint with a hair dryer or a heat gun for 30sec to 1min and then wriggle the PEX section off the fitting.