Question for Plumbers...

[TerryMiller]

RV's are all PEX.
I'm not sure if they still use cast iron for drains in homes with a crawl space as those aren't built much anymore?

I don't know about ALL RV's, but our supply lines are all PEX and the drains are some kind of black plastic "plumbing." I don't know if the black stuff is like PVC or not, but it isn't ever under pressure.

And the comment made about PEX being better with regards to freezing, I have some evidence of that. Our RV is well insulated, but if it gets down to zero degrees or below, the hot water line from the water manifold to the kitchen sink will freeze up. It has done that about 3 times in the last 12 years, but has never broken or split.

 

[Raido Free America]

I saw this on YouTube and wondered if what they say about CPVC is true. While we don't have any of it in our RV, I have seen it used in a number of homes.

I'm no plumber but have done some of my own plumbing. I don't think glued PVC meets plumbing codes for homes? It used to be rigid copper, with sweated joints, and I think it's the newer type PVC with heat welded joints, what ever that is called, now? I have used PVC sch 40, with gluded joints in out buildings for water, and 150 psi air, for over 40 years, with no problem!

 

[okcBob]

pex a is supposed to be better then pex b.
Different connectors too

 

[Shinneryfarmer]

Replumbed three homes with PVC and CPVC to this day I know two have never had leaks in either. The first one I replaced galvanized and copper that was deteriorating after 30 yrs. The second one replaced PEX after multiple leaks, some due to freezes but biggest culprit was connection's. My current home I replaced galvanized and copper that was deteriorating again due to age 16 yrs ago. The first home I still own and is going on 35 yrs..
Use the proper glue for CPVC, any piping running through walls gets replaced with sweated copper till it exits wall also insulate efficiently. I have had many years of worry free plumbing. Sure the occasional dripping faucet or toilet float but have never had to make a repair to CPVC or PVC that I have installed.
The new PEX I hear is pretty good stuff but still hear of leaks from freezing. Was it installed properly I don't know. But till PVC and CPVC fail me I'm sticking with it.

 

[SoonerP226]

I don’t think cast iron is used much anymore for drains

From what I understand, iron pipe hasn't been common in Oklahoma (at least in soil-contacting applications) in a long time because the soil is corrosive to ferrous metals--after all, the red Oklahoma clay gets its color from oxidized iron.