Plumbing pipe sizes?

[luvrbus]

Your higher end coaches manufactures like Newell and Marathon offer a up grade to copper the few I been around was never a problem.
Face it guys the cost is why people use Pex not that it better you don't see it used in your AC, fridges, the OEM heating systems or your radiator lol

good luck

[Dave5Cs]

Grant;

Remember in CA. that you need to use flex connectors on all gas appliances. Ours was all 1/2' Copper when we bought it. Gas door must be labeled LPG and unlocked while traveling the state

We use 1/2" Pex and shark barb connectors with the squeeze Rings. No returns to tank but want to install that feature.Tank shutoff to run direct from water regulated incoming pedestal supply.

You can use Pex and ball valves to make your own manifold for a lot less if you by on line. Put on a couple of extra valves for later use if needed and just cap them off.

Dave

[JohnEd]

Pip and Gus gave some excellent advice that should be followed.  Luvrbus, the one that contradicted both is also 100% correct.  There is no rub between them.  Copper, tube or pipe, are superb and long lasting.  NEVER EVER use compression fittings in a RV.  I recently repaired a rotted floor bigger than the footprint of my HW heater due to a seep from compressions that I had insulated and wrapped many years ago.  It only dripped a little back under my kit cabinets wayyyyy back in a hole and it was just as bad a place to be working on plumbing as it is replacing the floor.  ONLY use those spiffy solder fittings and I don't care what the big boys do if they use compressions.  Solder is more fun and I felt like an old world craftsman and that is surely a stretch.

Pex has the advantage of surviving a freeze, I am told.  It is easier and cheaper.  It does not go around corners as well as copper and you can't make an install look as neat and professional.  For my money.  Oh, yeah, and pex doesn't even compare to copper in terms of polishability.

Do it your way.  They both work if you follow the rules.

John

[dougyes]

One pump, 1/2 "pex for all, large diaphragm pressure tank, no pressure problems with two showers.

[belfert]

Why would I spend more money for copper to end up with a completely ridgid system that needs to be supported properly to avoid vibration?

I've seen some new million dollar houses plumbed with PEX and I wouldn't hesitate to buy a house with PEX properly installed in it. 

[Brassman]

In plastic, polybutylene was once the new and best thing. Look what happened there (though, I plumbed a house 25 years ago with it and it still works great; just have to tighten the fittings if you hard freeze the piping).

I'm doing pex because it is so easy, and is freeze tolerant. Copper tubing with flare fittings would work well in a bus, though expensive.

[luvrbus]

 Brian,I don't recall Grant buying a million dollar house read the post he said he had 3/8 pex or 1/2 inch copper and you need to do your home work on copper some of it will stand a lot of vibiration.
Fwiw here in AZ they install the Pex in the attic and they are having a few problems with the heat in the attic I have a few of the million dollar homes around me and I see what happens the stuff could be the poly pipe of years gone time will tell.

[Seayfam]

Not to argue copper are anything, but in my bus the main reason I went pex is, when I went and picked it up, it was froze and busted. I looked at everything and thought I could just fix the busted places. When I thought I had a good spot, the copper was swelled and wouldn't accept a fitting. I pressure tested main runs and there were leaks everyware. In my bus these runs were buried in between the tiled floor and the sheetmetal in the bays and was sprayfoamed in.

So I had to completely gut the inside of the bus where all the plumbing is. I didn't want to take the chance here in Alaska to have it freeze again. I figured with pex the only place I might have a problem is the fittings. Also the pex was real fast and inexpensive. I used red for hot and blue for cold, so no second guessing. You also don't have to worry about water hammer as bad.

But copper is good. These are just my reasoning's.

Gary

[luvrbus]

If I was doing a bus today I probably would use pex also but copper is not bad the trick to both is make it assessable for repair when needed I have had to rip out cabinets,floors and walls to repair pex and poly same with the copper 


good luck

[robertglines1]

One rule of thumb I make sure no matter how slight I make the runs down hill so in winter it drains to lowest point and winter drain.

[Seayfam]

One rule of thumb I make sure no matter how slight I make the runs down hill so in winter it drains to lowest point and winter drain.

This is also what I did. I also have low point drains like you would see in the new S&S models.

Gary

[Len Silva]

I have plumbed a couple of conversions in CPVC and as far as I know, they have been running around for many years without a problem.  Probably the cheapest and simplest way in a new conversion, might be hard to retrofit an existing one.

[gus]

The problem with polybutylene was only in the fittings, not the pipe. I have a bunch of underground PB pipe that has never leaked in 29 years, including fittings, plus all my feed pipes to faucets and toilets are PB with never a leak.

I don't know how its freeze resistance compares to Pex but it is pretty good.

[Tom Y]

Grant, I ran 3/8 od 1/4 id. Very happy with it. I ran the lines to the bath and teed off. No manifold, used 1/2 at the hot water then teed off with lines to K sink and bath. I do not flush when I shower or use the sink. The small line gets the hot water to you faster, Not wasting water.  Tom Y

[coloradorich]

On all of my fresh water pipes I used cvpc, 3/4in. comming in to tank and water heater. All other lines are 1/2in. cvpc. Have been full time for 8 years with no leaks or broken pipes. All sink and shower drains are 1 1/2in pvc. Comode is directly above tank so non problem there. Standard dump valves and hose connections. The only copper pipe is the tubbing used for propane lines.