2.5" ABS, DO FITTINGS STILL EXIST?

[karl olsen]

Howdy, I've come upon a missing link. I'm remodeling a bathroom, and the toilet vent is 2.5" ABS. Did companies stop making these fittings? Just too odd of a size? I'm only replacing the pipe through floor and hooking back up to old "Y", don't want to have to run new 2" all the way through roof.

 

[Mikey]

The OD of 2" ABS is actually 2 3/8", so it might look like 2 1/2" to the untrained eye.

 

[karl olsen]

See thats the issue, i am a well trained eye. 17 years pipefitting in shipyards and refineries. OD is 2 7/8", 2 1/2" pipe. I've looked at my local hardware stores, even online. Find nothing out in the world for this size. goes from 2 to 3 with the half missing. So I'm just wondering if it was eliminated for some reason? was thinking of using a rubber coupling, it's in a wall but shouldn't ever get water that high up.

 

[ExtraMilePlumbing]

Go with the rubber coupling, i never had to work with 21/2”abs

 

[karl olsen]

Thanks mister. Just find it weird that a whole size seems to be gone. Improvise adapt overcome.

 

[Diehard]

Transition to 2-1/2" PVC

 

[frodo]

Measure the od and id of your 2 1/2'' pipe and see if it fits into a 3'' or a 2'' fits into it


[ATTACH =full]20245[/ATTACH]

 

[Diehard]

Not sure what you are saying with these pipe sizes, etc.
ABS dimension's are the same as PVC.
Those ID's you show are incorrect.(I believe you subtracted only one wall thickness.)
The only way you could get close to matching an OD of one size to the ID of another (or vice-versa) would be with different schedule pipe. And even then may not match properly to allow gluing it.

 

[frodo]

The only way you could get close to matching an OD of one size to the ID of another (or vice-versa) would be with different schedule pipe. And even then may not match properly to allow gluing it.

I disagree, a 3'' fitting fits inside a 4'' pipe
4'' inside 6
etc etc
there are many combinations, that you are only aware of if you are hands on

 

[Diehard]

Too vague!
Are you talking OD of a bell/socket end of a fitting?
Are you talking specific pipe schedules?
Are you talking a fit that can be glued?

 

[frodo]

A sch 40 pvc -3'' fitting, will fit into a 4'' sch 40 pipe
A 3/4 fitting will fit inside a 1 1/4 pipe

and is tight enough to glue

there are other combinations also

 

[Diehard]

Okay...now you're being specific enough so I know what you're talking about. Wasn't able to get that from your first post where you were comparing pipe ID's & OD's.

But I still don't understand why try to make transition with OD's of ftgs when 2 1/2" PVC (sch's) appears to be available.

 

[frodo]

Okay...now you're being specific enough so I know what you're talking about. Wasn't able to get that from your first post where you were comparing pipe ID's & OD's.

But I still don't understand why try to make transition with OD's of ftgs when 2 1/2" PVC (sch's) appears to be available.

if they are available then post a 2 1/2'' x 2'' reducer abs/sch 40

 

[Diehard]

if they are available then post a 2 1/2'' x 2'' reducer abs/sch 40

Lost me again. Why a reducer to 2".
He said he had 2 1/2" and didn't want to have to run 2".
We're just talking new 2-1/2" PVC connecting to existing 2-1/2"ABS.

He may have already done it by now.

 

[frodo]

But I still don't understand why try to make transition with OD's of ftgs when 2 1/2" PVC (sch's) appears to be available.

the answer is simple. they are not available

 

[Diehard]

the answer is simple. they are not available

I wasn't aware of that. I was just going by what I saw on the web.
I think you should have brought that up sooner. Well whatever.

https://www.usplastic.com/catalog/item.aspx?itemid=38258

https://www.lowes.com/pd/Charlotte-Pipe-2-1-2-in-x-20-ft-300-Schedule-40-PVC-Pipe/50192273

https://www.grainger.com/category/plumbing/pipe-tubing-and-fittings/pipe-fittings/pvc-pipe-fittings?attrs=Pipe+Size+-+Pipe+Fitting|2-1/2"&filters=attrs

https://pvcpipesupplies.com/2-1-2-s...-yWzdO_L4wcKhaUOo72Ww6mm2rGtFhNYaAqhgEALw_wcB

ETC.

 

[Mikey]

Here you go:
https://www.fernco.com/dimensional-drawings/1056-25022

Not shielded, so I think it must be accessible, but your local AHJ can tell you for sure.

From the Web, italics mine: "Fernco (Rubber) fittings are not approved in wall framing unless they have a metal sheathed hose clamp assembly covering the entire fitting as part of the design, Which limit them to straight couplings or reducing couplings. The reason is that vermin can chew through the rubber."

I haven't found a shielded 2" - 2 1/2" coupling yet, but you might be allowed to add a stainless steel shear ring to the unshielded coupling, which would not result in an an as-designed assembly, but I'd bet most inspectors would approve it:

https://www.fernco.com/plumbing/shielded-couplings/stainless-steel-shear-rings

 

[frodo]

I wasn't aware of that. I was just going by what I saw on the web.
I think you should have brought that up sooner. Well whatever.

https://www.usplastic.com/catalog/item.aspx?itemid=38258

https://www.lowes.com/pd/Charlotte-Pipe-2-1-2-in-x-20-ft-300-Schedule-40-PVC-Pipe/50192273

https://www.grainger.com/category/plumbing/pipe-tubing-and-fittings/pipe-fittings/pvc-pipe-fittings?attrs=Pipe+Size+-+Pipe+Fitting|2-1/2"&filters=attrs

https://pvcpipesupplies.com/2-1-2-s...-yWzdO_L4wcKhaUOo72Ww6mm2rGtFhNYaAqhgEALw_wcB

ETC.

DWV !!!!!!!!!!!!! pressure fittings are not allowed in a dwv system
they are for hooking up the well

We have to install by code.

 

[frodo]

Here you go:
https://www.fernco.com/dimensional-drawings/1056-25022

surprised you found one

your google foo must be strong

 

[Diehard]

Go with the rubber coupling, i never had to work with 21/2”abs

A sch 40 pvc -3'' fitting, will fit into a 4'' sch 40 pipe
A 3/4 fitting will fit inside a 1 1/4 pipe

and is tight enough to glue

there are other combinations also

DWV !!!!!!!!!!!!! pressure fittings are not allowed in a dwv system
they are for hooking up the well

We have to install by code.

I'm getting a bit dizzy. I think I'll call it a day.