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Why ABS instead of PVC?

STBRetired
Explorer
Explorer
I have noticed that all the DWV plumbing in my MH is ABS plastic. Is there a technical reason why ABS is used exclusively? Is it just that ABS costs about 1/2 of what PVC costs? If I redo a goodly portion of my drain system can I use PVC, which is much more readily available where I live. I understand there are specific methods that must be used where the ABS and PVC meet, but is there any reason other than cost that I cannot use PVC?
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56 REPLIES 56

drsteve
Explorer
Explorer
Cement comes in a bag that says CEMENT. Cement mixed with water and gravel/sand is concrete. After it hardens it is still called concrete.
2006 Silverado 1500HD Crew Cab 2WD 6.0L 3.73 8600 GVWR
2018 Coachmen Catalina Legacy Edition 223RBS
1991 Palomino Filly PUP

msmith1_wa
Explorer
Explorer
free radical wrote:
Ralph Cramden wrote:
Cummins12V98 wrote:
Ralph Cramden wrote:
Cummins12V98 wrote:
BobsYourUncle wrote:
Stick to ABS for all your drain stuff.
That's what it's made for.
I've never measured it but the wall on ABS is at least twice as thick as PVC.
2 different plastics here, and each designed for different purposes.
You can throw a chunk of ABS off a building and won't hurt it much.
Forget the PVC for the purpose you describe.

Drain fittings and more are all designed to fit with ABS, not PVC


Are you a plumber?


Just because someone slings some s**t does not automatically make them a plumber.


You acknowledge SH!T runs downhill and payday is on Fridays, you are a Plumber!


Along with hot's on the left and cold's on the right, and don't chew your finger nails.
Plenty of concrete pros on these RV boards also. They know it usually comes in a truck LOL.

Fwiw I have never ever seen concrete coming in a truck..

Cement mix comes in a truck,it becomes concrete later when it hardens
Details gentlemen plz
😛



ce·ment

noun
1.
a powdery substance made with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete.
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2016 Evergreen Amped 28FS

SpeakEasy
Explorer
Explorer
STBRetired wrote:
I will have to try that freezing experiment. I don't have any extra ABS laying around but I can probably come up with some. It gets pretty cold in the winter (can you say Polar Vortex?) and I would not want to have a drain line snap somewhere in the MH while bringing it back from storage.


Actually, you probably do have some ABS lying around. At least, if you have kids or grandkids, you probably do. Legos are made of ABS.

(And another little bit of trivia: you can "melt" Legos in MEK to make a slurry that can be used as ABS "glue" or "filler" if you ever need to. Not that you'd ever need to.)

-Speak
It's just Mrs. SpeakEasy and me now (empty-nesters). But we can choose from among 7 grandchildren to drag along with us!



2014 F-150 Super Crew Short Bed 3.5L Ecoboost
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Westcoasting
Explorer
Explorer
free radical wrote:
Ralph Cramden wrote:
Cummins12V98 wrote:
Ralph Cramden wrote:
Cummins12V98 wrote:
BobsYourUncle wrote:
Stick to ABS for all your drain stuff.
That's what it's made for.
I've never measured it but the wall on ABS is at least twice as thick as PVC.
2 different plastics here, and each designed for different purposes.
You can throw a chunk of ABS off a building and won't hurt it much.
Forget the PVC for the purpose you describe.

Drain fittings and more are all designed to fit with ABS, not PVC


Are you a plumber?


Just because someone slings some s**t does not automatically make them a plumber.


You acknowledge SH!T runs downhill and payday is on Fridays, you are a Plumber!


Along with hot's on the left and cold's on the right, and don't chew your finger nails.
Plenty of concrete pros on these RV boards also. They know it usually comes in a truck LOL.

Fwiw I have never ever seen concrete coming in a truck..

Cement mix comes in a truck,it becomes concrete later when it hardens
Details gentlemen plz
😛

Turn the truck off and it is so concrete in a few hours!

free_radical
Explorer
Explorer
Ralph Cramden wrote:
Cummins12V98 wrote:
Ralph Cramden wrote:
Cummins12V98 wrote:
BobsYourUncle wrote:
Stick to ABS for all your drain stuff.
That's what it's made for.
I've never measured it but the wall on ABS is at least twice as thick as PVC.
2 different plastics here, and each designed for different purposes.
You can throw a chunk of ABS off a building and won't hurt it much.
Forget the PVC for the purpose you describe.

Drain fittings and more are all designed to fit with ABS, not PVC


Are you a plumber?


Just because someone slings some s**t does not automatically make them a plumber.


You acknowledge SH!T runs downhill and payday is on Fridays, you are a Plumber!


Along with hot's on the left and cold's on the right, and don't chew your finger nails.
Plenty of concrete pros on these RV boards also. They know it usually comes in a truck LOL.

Fwiw I have never ever seen concrete coming in a truck..

Cement mix comes in a truck,it becomes concrete later when it hardens
Details gentlemen plz
😛

Bobbo
Explorer II
Explorer II
profdant139 wrote:
What in the world has happened to the civility that used to be the hallmark of this whole forum?

I have been on this forum for well over 10 years, and I have never noticed it to be the least little bit civil. As a matter of fact, I thought this particular thread had done a good job of not going over the top with insults and attacks.
Bobbo and Lin
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2017 Airstream Flying Cloud 23FB

Lantley
Nomad
Nomad
profdant139 wrote:
What in the world has happened to the civility that used to be the hallmark of this whole forum? The mods are doing their best, but they can't police everything.

Can't we disagree with each other politely?

Sorry for the rant, but I am confused by the overall tone. The sharp elbows are, without doubt, discouraging questions by newbies and others who really would like the benefit of the members' collective wisdom, which is considerable.

Thanks for considering this request!!

While I do respect your request. I didn't think this thread was so bad.
The conversation concerning "stuff flows downhill and payday is on Friday" is an old plumbers joke known by everyone in the trades.

I think the biggest point of this thread that Chum Lee shed some light on is PVC use vs. ABS is a very regional. Local Codes determine which product is used. The composition and additives used in ABS and PVC are regulated by local codes as well
If ABS is generally cheaper to manufacture as implied ealier in this post, than I'm sure the RV manufactures main reason for using it is price.
For the record I would have no problem using PVC in my RV. PVC is used exclusively in my area. ABS is not stocked at the big box stores or plumbing wholesalers in my area.
If I were concerned about the integrity of the pipe I may step up to schedule 40 PVC, otherwise I would just stick with foam or cellular core PVC pipe
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profdant139
Explorer II
Explorer II
What in the world has happened to the civility that used to be the hallmark of this whole forum? The mods are doing their best, but they can't police everything.

Can't we disagree with each other politely?

Sorry for the rant, but I am confused by the overall tone. The sharp elbows are, without doubt, discouraging questions by newbies and others who really would like the benefit of the members' collective wisdom, which is considerable.

Thanks for considering this request!!
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
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About our trailer
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Chum_lee
Explorer
Explorer
ken56 wrote:
My understanding is ABS is more UV resistant, PVC is not.


The truth is that ALL plastic (pipe) is subject to UV damage given enough time and substantial UV exposure. Pipe manufacturers add UV protectants to the plastic design mix (binding agents) before the extrusion process. Those additives can range from simple carbon black, (soot) to Calcium Carbonate, to colored pigments, to in some cases, fine grained sand (silt) as well as regrind (recycled) plastic from failed previous manufacturing runs. The purpose of the additive(s), which are usually solid at room temperature, is to provide a physical barrier that blocks the UV rays from penetrating into the wall of the pipe and limits the UV damage to the surface.

In plastic pipe, the additives are usually cheaper than the binders so the tendency is to add as much additive as possible and minimize the binder content. That's why some plastic pipe seems very durable and some pipe easily fractures like glass.

So, Why ABS instead of PVC? Because in the location where the plastic is used, of all a available approved products for a particular application, ABS is currently the cheapest.

Chum lee

drsteve
Explorer
Explorer
SparkDr wrote:
I didn’t really see any reason to post any “how to” info when I originally joined the convo as nobody had asked.


The discussion of methods of connecting PVC to ABS actually began on page 1...
2006 Silverado 1500HD Crew Cab 2WD 6.0L 3.73 8600 GVWR
2018 Coachmen Catalina Legacy Edition 223RBS
1991 Palomino Filly PUP

Cummins12V98
Explorer III
Explorer III
"Having said that, a mechanical connection is required by most codes. Fernco, male / female adapters, etc. But of course, codes don’t matter in RV’s so pick your own poison."

Thank you for your comments.
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myredracer
Explorer II
Explorer II
Here in Canada, our plumbing code requires ABS indoors (except for cast iron in some applications) and out to 6' beyond a building where it can then be run as PVC. ABS and PVC are readily available everywhere here. In the US, PVC is the standard in buildings. Not sure why the difference. It's annoying for us Canadians trying to by a few pieces of ABS in stores in the US. 'Course, you can always go to an RV dealer and pay like 10 times what it should be.

The reason ABS is used in RVs could be because of the applicable plumbing standard for RVs ((NFPA 1192?). Or it could be because exposed PVC becomes more brittle when exposed to cold temps and it's easier and better to run everything in ABS rather than having to deal with transition cement or Fernco fittings which could be problematic. Gluing PVC joints using primer requires some patience and skill and I can just imagine all the failed joints that could occur at the factories by the typical workforce they use. Cutting PVC is harder on tools. It could be, all things considered overall, using ABS is cheaper.

Unless you go with sched 40 PVC, ABS is strong as heck. ABS would be a better choice under an RV due to the potential for it being damaged. Glued joints in ABS last longer and are stronger. Unless primer is used first on PVC joints they can easily fail over time.

SparkDr
Explorer
Explorer
I guess I should’ve subscribed to the thread so as not to offend Cummins apparently. Quite honestly, these are the types of people and comments that I try not to engage with here. Regardless, I didn’t really see any reason to post any “how to” info when I originally joined the convo as nobody had asked. It was just assorted advice and opinion being passed around. Having said that, a mechanical connection is required by most codes. Fernco, male / female adapters, etc. But of course, codes don’t matter in RV’s so pick your own poison. I don’t see any reason to venture back to this thread so I’ll move on. Feel feel to continue to treat one another poorly in my absence.
May the Mods grant me the serenity to accept the opinions of those I cannot change,
the courage to offer input to those who are open to another way of thinking,
and the wisdom to shut up whenever I get too caught up in my own misconceived brilliance.

Ralph_Cramden
Explorer II
Explorer II
Cummins12V98 wrote:
Ralph Cramden wrote:
Cummins12V98 wrote:
BobsYourUncle wrote:
Stick to ABS for all your drain stuff.
That's what it's made for.
I've never measured it but the wall on ABS is at least twice as thick as PVC.
2 different plastics here, and each designed for different purposes.
You can throw a chunk of ABS off a building and won't hurt it much.
Forget the PVC for the purpose you describe.

Drain fittings and more are all designed to fit with ABS, not PVC


Are you a plumber?


Just because someone slings some s**t does not automatically make them a plumber.


You acknowledge SH!T runs downhill and payday is on Fridays, you are a Plumber!


Along with hot's on the left and cold's on the right, and don't chew your finger nails. Plenty of concrete pros on these RV boards also. They know it usually comes in a truck LOL.
Too many geezers, self appointed moderators, experts, and disappearing posts for me. Enjoy. How many times can the same thing be rehashed over and over?