Plumbing 101: resources, links

[Mr P]

I'd like folks to use this topic to share their recommended resources/links regarding all things RV plumbing related.

I see faroutride.com has some info, but they don't do black water

 

[jbeech]

I don't plan to do blackwater, either. As for the rest, PEX is your friend.

 

[Mr P]

Why PEX? Or, why not PVC, ect?

 

[desrtdog]

I don’t see many houses that use PVC for potable water - at least not inside. The beauty of PEX is that is flexible, so if you design your system cleverly enough, you can have one continuous run of pipe with no (or at least very minimal) joints. With PVC, every bend will require a joint (cemented) which means another potential leak point.

When using PEX, there are different types (A, B, C) …. A is what I believe most plumbers use in homes - it has expansion collars that hold the pipe to the barbed fitting (requires a special tool, but useable after you complete your build), and I think has an ever so slightly larger cross section… I’d avoid using SharkBite fittings (the ones that are push to connect…seems to me that these could be more prone to disconnecting under vibration although I don’t have any data to back that…

 

[ewo1]

PLUMBING
So it been quite a while that I don't do much work on the bus and now the central TX heat is really ramping up, is when I decided to start working on the bus again. go figure...

I was able to pickup a brand new Dometic 320 toilet for $150 and just got today a 65 gallon fresh water tank for $100 bucks, both on marketplace.
I am ordering a second water tank, they are $175 bucks, new.

Amazon.com

I'm goin with pex vs pvc piping.

My question to you guys is, tooling.

From strictly a "best no leak" connections on the pex.

What is best, clamping, crimping, compression or push to connect?

I really don't care about cost for parts or tooling just want to know your thoughts on "best connection".

 

[jbeech]

I replumbed my home from copper to PEX 15 years ago. All connections crimped. Three years ago, I plumbed my shop air lines, once again using PEX. No leaks, ever. Note; the fittings and rings cost a LOT less costly than push-on Sharkbite type fitting, which a pal used for his shop installation, and guess what? His don't leak, either! Anyway, while I'm a crimp guy, what you decide is up to you. Also, I'm a buy the good tool type, but you won't break the bank with one of these.

 

[ewo1]

I replumbed my home from copper to PEX 15 years ago. All connections crimped. Three years ago, I plumbed my shop air lines, once again using PEX. No leaks, ever. Note; the fittings and rings cost a LOT less costly than push-on Sharkbite type fitting, which a pal used for his shop installation, and guess what? His don't leak, either! Anyway, while I'm a crimp guy, what you decide is up to you. Also, I'm a buy the good tool type, but you won't break the bank with one of these.

Hey, thanks...
A friend of mine has a toothpick stick rv with push on connectors and he said he has had leaks occur. i guess too much vibrations cause them to leak?

I was reading the faroutride page that has been mentioned here a few times, they recommend clamping over crimping primarily due to not needing a go/no go gauge.

guess i'll go the clamping route...

 

[desrtdog]

So that confirms my suspicion re the push to connect fittings (aka sharkbite)…they are good for a quick fix if you have a pipe bust in your house, but long term behind a wall - not a fan…

As far as other fittings go, there are crimp (metal collars) which I’m told can be a little finicky getting them to seat (no experience here), and the compression collars which are plastic that you need the tool to expand, but then contract back and seal tight. When I had my home water heater replaced, the guy that did it used these…as did the guy who replaced a section of pipe following the great freeze of winter storm Yuri in 2021…
So after some research of the different types of PEX, I bought a 100’ spool and the “tool” from HD and used that for my plumbing.

If you’re I need of supplies, I still have a great deal of the PEX and can loan you the tool….

 

[nikitis]

Why PEX? Or, why not PVC, ect?

PVC isn't even good to use in a home. They are far more prone to leak is the main reason. Sealant used doesn't stand the test of time with water.

This isn't to say that people don't use PVC for parts of their water plumbing, but when they do it's normally for drains and not sections of plumbing under pressure. When Water pressure is applied it can expand and contract slightly, enough to break sealant over time.

Considering extra vibrations in a BUS, I highly do not recommend using PVC in that application.

I do not recommend.

PEX - While jbeech has had decent results with PEX. It's no substitute for copper, and will only on average last 1/3 as long as copper.

Most bus conversions statistically don't seem to make it beyond 10-20 years as they get discarded, or sold and then renovated, this is kind of the life expectancy we should be shooting for unless you really want this thing in your life for 60 years.. So PEX is sufficint for a 10-20 year bus. Around that time though, you may begin to have issues with the installed PEX. it is the cheaper solution, but PEX replaced copper due to rising prices of copper piping. This is why plumbers don't use it any longer by default. Not because it is better, but because it's affordable compared to copper piping.

PEX Should absolutely NOT be used in an extreme cold climate in a BUS. They will burst if it is full of water and it ices over expanding. Copper can hold much better in such a climate, but it's not immune either.

A Pro for PEX though is ease of installation. Applying fittings/ends to PEX is easier to do than on copper which is another reason people like using it.

Another pro for copper is it's metal and it will absorb and transfer a lot of the cold along the pipe itself like a heatsink would do.

My conclusion. PEX is okay to use on a bus if you plan to only own the bus 10-20 years. I would never use PEX in my house because I want my piping to last 50+ years minimum. If going to extreme climate, get copper piping for the Bus.

 

[Mr P]

^ I used CPVC. I'm in a home built in 1985 ish, never had a problem with the plumbing.

PEX is supposed to tolerate freezing way better than copper. Here's a link. Best Pipe for Freezing Conditions -- What Are They Made Of?

 

[desrtdog]

^ I used CPVC. I'm in a home built in 1985 ish, never had a problem with the plumbing.

PEX is supposed to tolerate freezing way better than copper. Here's a link. Best Pipe for Freezing Conditions -- What Are They Made Of?

True statement.

Water at its most dense at 4 degrees C, less dense when frozen. So as water freezes it expands…pipes with it. Copper pipes fail when frozen because they split as the water freezes … not a problem until the water in them thaws and then the problems start. PEX is more flexible than copper, thus less prone to failure when expanded due to water freezing. The other issue with copper is you need joints at every corner or bend. You can buy PEX in a spool ranging from 25’ and up, so you can literally run a continuous piece from the water pump to the sink or water heater, bending that piece around corners it needed … means no joints in hard to reach places … Ali don’t have to worry about catching you bus on fire when connecting pieces…

PEX is what I used, and wouldn’t change if I was till do it again…

 

[Jolly Roger bus 223]

i do alot of commercial plumbing and use mainly copper for anything potable water and exposed to freezing even with insulation can freeze and bust.
the residential pro's swear by pex piping and i have used some of it more connecting my copper for testing and have not had any problems while under high pressure testing ( 150-180 psi).
the residential pro's i talk to at my almost daily supply house swear PEX A i think that is the expansion type and crimp rings.
the expansion type idea is with regular pex by using type b or c the fitting slides into the pipe and actually decreases the pipe inner diameter by an 1/8" for each fitting which with a bunch of fitttings elbows tees couplings etc, and a low flow capacity pump could/ will decrease the flow of 1/2" pipng to 3/8" piping and make you think your pump is undersized but it is actually the piping connections.
PEX A uses an expansion tool to allow for bigger fittings to maintain the inner diameter of the pipe for full flow through the fittings.
PEX will expand and contract better than copper that will help in freeezing temps.
i have used shark biter fittings in my adventures as well more for testing and or emergency repairs where we cant get the valve to shut off enough for soldering or brazing and if the piping no matter what kind does not have a square cut and deburred and the piping is not supported allowing weight on the fiiting or the piping in and out is not perfectly square and supported they will leak.

 

[Mr P]

But, if we could shift gears to add links/resources about the choices of pumps, heaters, accumulators, filters, ect. My head is spinning wondering about pump voltage; 12v DC for easiest on highway, non shore power stops, or 120v AC and depend on an inverter on the road? What flow rating for showering, ect?

 

[Cannabus]

I'd like folks to use this topic to share their recommended resources/links regarding all things RV plumbing related.

I see faroutride.com has some info, but they don't do black water

You want apex A with expansion rings. You can buy a hand expansion tool on EBay. I got mine for $25 there. It’s the easiest to work with.

Pex A is the best is best in case your bus accidently freezes as it can expand with the ice and will contract to its original size. use brass elbows and connectors and avoid plastic connectors. It has better water flow rates than B or C. Do not use toothed connectors ever. Assemble pipe sets before installing. Pipes can be bent somewhat in case you need to go under or over other items.

If properly installed you will have no leaks as mines hasn’t in 2 1/2 years going. It’s also tasteless and and passes tough CA purity laws.

Buy your pipes at a good plumber supply house. I bought 16’ lengths for under $5.

It is Cuck Cassidy’s and mine recommended. Check out Chuck’s vids on YouTube.

Best of luck!

 

[nikitis]

May be related to climate, I dunno, I live in the south east, and it does freeze but not terribly so. I going by experience here. I've personally known a couple of guys who's houses had to be redone 2 times each when they used Pex because they burst. They had pressure regulators at the front of their houses to ensure it wasn't over pressurized, and they didn't burst during cold season either. Was in the spring and summer.

As Jolly Roger pointed out, and many of you have pointed out, it is far easier to use PEX which is why I think Plumbers switch to it for their jobs. Plumbers hate having to solder connections when you can just snap it on with a quick tool. But other than here on this forum, I've never heard the opinion that Pex was better for the customer than copper. Metal can also expand and contract with cold temps.

And in my asking of plumbers why when doing jobs for me, they state they like copper but it's too pricey for most and it's easier to install Pex is what they say.

 

[Cannabus]

I recommend anyone using city water or even trailer parks connections to use a water pressure regulators. It’s recommended for all RV’s regardless of what piping they use including copper. Most Pex are rated for 180 degrees at 80 psi which for me is way too high for my water temperature. Pex is susceptible to clorine degradation but keep in mind most trailer parks and suburban water hook ups use well water. No matter, I wouldn’t recommend having water pressure above 80 psi on any RV system and temperature around 140 or less. Water pressure regulators are cheap and considered essential even for homes on city water.

 

[Cannabus]

But, if we could shift gears to add links/resources about the choices of pumps, heaters, accumulators, filters, ect. My head is spinning wondering about pump voltage; 12v DC for easiest on highway, non shore power stops, or 120v AC and depend on an inverter on the road? What flow rating for showering, ect?

12volt is preferred for RV’s and a good pump should be at least 3.5 gpm. Your faucets should be within that range