80% plumbed

For the most part I resisted the temptation to work on the Caravel over the weekend.  There were other things to do and the end of the plumbing project is within sight, so it seemed like a good idea to take a break for a little while.

Over the weekend the only major progress was on the last really tricky bit: the plumbing assembly for the water heater bypass and the connections heading off to the two sinks.  I built it in about an hour.  You can see an early draft of it in the picture below, not quite complete but showing all three of the ball valves and some of the major connections.

IMG_1832This piece will stand upright next to the side of the water heater (so the blue line will be at the bottom), and thus tuck in neatly to allow lots of free space under the bathroom sink where we formerly had wild plumbing lines going everywhere and blocking everything.  The draft in the photo doesn’t show two additional tees that I added later.  As with the Dreaded Closet Manifold, it was designed so that access to the three ball valves would be much easier than before, and of course it’s color-coded too.

This was definitely the hardest piece of the project but I wouldn’t call it hard, really.  The whole project has been fairly easy, although time-consuming, and despite the challenges I’ve really appreciated the chance to do this and learn some new skills.

I’ve since completed the assembly with tees for the sinks and swivel fittings for the water heater connections, and test-fitted it for the umpteenth time.  All that remains is to fix couple of under-sink mistakes I made earlier, and then crimp it into place.

The mistakes are going to hold up the project, though, because I need a de-crimping tool.  I had gotten this far without purchasing that tool, which is used to cut off crimps without sacrificing the brass fittings.  Then I made two serious mistakes: one bad crimp, and I rather stupidly put in two tees to connect the cold water side of the bathroom faucet.  Obviously I only need one.

I could correct these mistakes by cutting out and sacrificing a bunch of completed sections, but I decided to go ahead and purchase the de-crimping tool (about $20) so that I will be able to make other repairs or modifications later.  I added this to a final parts order on Friday and probably won’t get it until late this week, so in the meantime not much is going to get done.

Once the parts do arrive, the project list looks like this:

  1. Hook up sinks
  2. Finish connecting water heater bypass to heater and main lines
  3. Install new city water fill
  4. Add experimental water hammer arrestor (*)
  5. Add foam insulation and pipe clamps for sound dampening and security
  6. Pressurize system and check for leaks (first with water pump, then with city water pressure)
  7. Test for noise & add insulation as needed.

Notice I haven’t included the item “Fix leaks”.  There won’t be any.  Right?

The water hammer arrestor is a complete experiment. I’m wondering if it will have any effect on the pulsing that the water pump transmits through the entire system.  You can insulate and clamp down the pipes so they don’t move, but the vibration is still transmitted through the water, so the vibration can re-appear in the pipes downstream.

RV stores sell a device called a pressure accumulator which is supposed to smooth out the water flow, but I’ve tried one and found it ineffective.  The water hammer arrestor is designed to stop one heavy “slug” of water pressure rather than a constant series of pulses, but I’m hoping it will have some positive effect anyway.  I’m going to plumb it in on the main line from the water pump and see what happens.

With this project mostly under wraps, and the weather finally warming up here (I know, no pity from the northerners), it’s time to get serious about the Safari floor project.  That’s on my list for later this week.


  1. Doug Rowbottom says

    Rich, I find it much better to pressure test with air before using water. It’s much easier to clean up if there is a leak.

  2. Tom Turner says

    I used something like this and it is one of the best things I have done to my motorhome. It gets rid of the vibration but better than that it is an accumulator which means that the pump doesn’t short cycle at low flow and the water flow is constant. I wouldn’t have a system without one. It will also keep the pressure relief valve from weeping when the water heater cycles on. Also it should be less expensive from a box or hardware store than from a camper supply. Hope this helps.