Can’t couple sch 40 to sch 80 - sand it? Heat it?

[ballardFan]

I have a line repair 7 ft down in a vault. The outgoing pipe is what appears to be gray sch 80 2”. I need to couple it to a 2” schedule 40 pipe that is the incoming line.

Previously there was some galvanized pipe and valves between the two types of pvc pipe. The sch40 to galv used a bronze dressler style compression coupling and the galv to sch80 used a convoluted double female coupler that accepted a sch80 male adapter.

anyway I cannot for the life of me with just primer and cement get a sch 40 coupler onto this sch 80 pipe stub. It’s very close but too tight. I tried several fittings to make sure it wasn't a casting issue.

I tried a mallet. I tried sanding but could sand more. I do not want to use heat unless that is what I hear.

Would you sand it more? I used 220.

It’s under 7 ft down near the edge of a concrete vault and I can’t see any marking on the stubbed piece of gray pipe.

I am without water so would like to get it fixed ASAP.

 

[Valveman]

Sch 40 and Sch 80 should be the same OD?

 

[Sponsor]

 

[Tuttles Revenge]

I assume this must be water pressure.. Sanding compromises the integrity of the pipe.. but maybe no less than the sch40. Seems like a gamble. Perhaps a Ford style or Romac coupler? I've used romac to transition from steel to wirsbo in an 1.5" water service.

 

[Taylorjm]

the od of sch 40 and 80 are the same and can be glued together without any kind of mallets or sanding. The inside diameter is different because sch 80 has a thicker wall. If you can't get the pipes together, then you either have the wrong size, or a different type of pipe.

 

[Reach4]

What does the OD of your grey pipe measure with your digital caliper?

 

[ballardFan]

I did measure OD on the sch 80 pipe just as a sanity check. It is definitely sch 80 and normal OD.

The fit issue stemmed from 2 things:

1) I had cut it with a set of PVC cutters and that seemed to make too sharp of an edge. I chamfered it lightly at the edge.
2) The remainder of the stub had some abrasions from rocks/soil after being underground 30 years. I sanded that a bit more with 220 grit till it felt nicer.

With with some primer, glue and a small block of wood to persuade it the coupler finally got on.

It was hard to really troubleshoot originally as it was dark and muddy after the leak. Today it was dried out and daylight so easier to work on.

Thanks all!

 

[Tuttles Revenge]

Give that glued joint LOTS of time to cure before pressurizing.