I wanted to construct experimental setup using pressure pipe but be able to change/dismantle it as required.  Gluing the various fittings together is quite expensive and if you need to make a small change you have to either throw it away or spend hours with a hot air gun trying to separate the parts.  Once you've finished you can dismantle quickly and reuse the pressure pipe fittings for some other project.

I made simple clamps for 40mm and 50mm pressure pipe and also 100mm storm water pipe. You could easily adapt the concept for other sized pipes.  You press fit the standard pressure pipe fittings together, then clamp them together with this system.   The clamps are held on the pipe with cheap hose clamps and then 3/16" threaded bar cut to required size. You then put washers/nuts on either side of the threaded bar and tighten.  Note you put the plastic parts on such that the threaded bar compresses the layers of printed plastic which is much stronger than the opposite configuration.

For the 90 deg clamps for 50mm pressure pipe I originally made the outer part as one piece but this requires lots of supports and is not as strong in one direction (the direction that tends to pull the layers apart).  So there is also a split version.   You would print this in the orientation  that the threaded bar pulls parallel to the printed layers which is stronger.

This system worked quite well and I had 4 pool pumps running flat out and the system held together with no leaks.  It used 40mm, 50mm pressure pipe, DWC and stormwater pipe all held together with these parts.   If you want to see a video of it in action you can see it here (It was an attempt to make a flow tank with water velocities in the 60-80Km/hr range for the purpose of testing stuff for windsurfing (like fins)