2.5" ABS, DO FITTINGS STILL EXIST?

Help Support Plumbing Forums:

karl olsen

New Member
Joined
Mar 16, 2019
Messages
3
Reaction score
0
Location
Freeland, WA
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.
 

karl olsen

New Member
Joined
Mar 16, 2019
Messages
3
Reaction score
0
Location
Freeland, WA
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.
 

frodo

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,139
Reaction score
2,583
Location
right here right now, over there later on.
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


[ATTACHabs__pipe_deminsion_.png =full]20245[/ATTACH]
 
Last edited:

Diehard

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
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

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,139
Reaction score
2,583
Location
right here right now, over there later on.
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

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
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?
PVC Dimensions.jpg
 

frodo

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,139
Reaction score
2,583
Location
right here right now, over there later on.
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

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
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

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,139
Reaction score
2,583
Location
right here right now, over there later on.
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

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
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.:D
 

Mikey

Well-Known Member
Supporting Member
Joined
Jul 15, 2018
Messages
289
Reaction score
49
Location
Northwest Washington
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
 
Last edited:

frodo

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,139
Reaction score
2,583
Location
right here right now, over there later on.

Diehard

Well-Known Member
Joined
Aug 19, 2017
Messages
2,640
Reaction score
469
Location
North Reading, Mass.
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.
thanks.jpg
 
Top