I just finished replacing all the copper plumping in our 67 Safari 22'. The old plumbing had many blown up pipes and splits and repairs so I pulled it and started from scratch using a diagram I made, and the old pipes as a template.
I wanted to pass on what I think is an innovative solution to easy reinstalling and testing.
I divided the rear plumbing into 4 segments
1. Cold water portsidea(inlet, regulator,toilet,pump/tank,cold shwr)
2. cold water starboard (WHtr,kitch,bath sink)
3. hot water portside (only feeding one 3/8" to Hot shower)
4. hot water starboard(from WHtr to kitch, bath sink)
I built each qadrant independently and soldered a 1/2" threaded fitting on each of the four. All major soldering was done outside our bauxite bisquit.
This made it real easy to pressure test each quadrant independently using a 1/2"to3/4" adapter and a water hose.
It also made installing each quadrant real easy as I used a 12"x1/2"x1/2" stainless braided line in between quadrants in the rear. (actually one 12" and one 20") as this method gives a lot of leeway for precision errors.
Headaches encountered centered around the industry standard of rating various pipes by I.D. And O.D. (inner and outer diameter) interchangeably. I used type "L" as this is thicker and the 1/2" ID is 5/8' OD. This is true for all sizes so sending Marlo to get pipe without a sample generated another trip to the "big box" store.
I can easily unscrew any quadrant for modifications without pulling the whole system or heating up 5/8" pipe in confined spaces. The 3/8" and 1/4" fittings heat up easily with a dish to deflect flame from plastic areas.
I added two cut off valves to isolate the WHtr for easy removal etc.. I used braided stainless to the faucetts as well for easy replacement when needed. Oh yeah, I used a big makita side angle grinder to remove (destroy) the bath faucett. It was rusted so hard at the bottom that I thought I would break the plastic sink with more force, So I ground it (brass) down to the nub from the top after I discovered the plastic is protected by big honkin' 3"x1/8" washers below the faucett assembly. It dropped down easily after my relentless rednek assault!