4" gasketed SDR 35 after sewage grinder

Zman

I am working on a project where an existing home is having a sewage backup issue on the service line between the house and the main. It turns out the utility contractor that installed the stub to the lot prior to the house being built ran the line dead flat. Because of the existing elevations between the house and the main, there is no way to fix the problem. A contractor is now suggesting adding a grinder station just outside the house but says that the existing 4" SDR 35 gasketed pipe running to the main needs to be replaced with pressure pipe. I totally get that if there was any vertical head involved he would be correct. I just can't see 10 GPM or so running through a 4" flat pipe building any pressure. I think that 4" SDR 35 is good to about 5 #. Any thoughts?

ChrisJ

https://forum.heatinghelp.com/discussion/197183/4-gasketed-sdr-35-after-sewage-grinder

Best I could find is it's considered gravity sewer pipe and therefore has no pressure rating other than it's stiffness rating.

To me that means no one will say it can handle any positive pressure at all regardless of what it could actually do real world.

mattmia2

i mean my thought would be to run the pipes above the floor in the basement if you had to to avoid having an ejector pump…

ChrisJ

https://forum.heatinghelp.com/discussion/comment/1802763#Comment_1802763

I didn't see any mention of a basement or where the main drain and sewer connection is in reference to it?

Zman

https://forum.heatinghelp.com/discussion/comment/1802763#Comment_1802763

The house is slab on grade and the piping in the interior slab cannot be changed. The issue starts outside the building. Neither the pipe leaving the building nor the sewer main can change elevation. The line plugs up every few years due to the lack of slope of the pipe. A much cheaper option would be to set up an motorized valve on a timer to dump a slug of water down the drain on a schedule to clear the line.

Mad Dog_2

If it's occurring only every few years, I would cut in a full size wye with clean out as far back to the foundation of home and flush from the nearest fire hydrant with a 2 1/2" hose every 6 months. Work it out with your Local FD and make nice. Mad Dog

hot_rod

There is no pressure rating on ASTM D 3034 PVC.

How long of a run? Could you push a 2" schedule 40 inside and pump to the main where it is a pitched gravity.

Someone makes a pump capable of that.

mattmia2

I come from the land where things under ground have to start at 40" if you don't want them to freeze.

I considered sticking polyethylene or something inside my orangeburg until it got to the clay stub at the main and using a pump.

Mad Dog_2

What state are you in, Matt? Mad Dog

Intplm.

Hey there @Zman

Have you considered using the current SDR pipe as a sleeve and installing a smaller diameter pipe inside creating pitch from within?

If this is possible you could either go without a pump depending on the pitch or use a conventional sewage pump, depending on the orientation/ distance of the run.

Zman

https://forum.heatinghelp.com/discussion/comment/1802872#Comment_1802872

How would you adapt the pipe at the tap? I could see how you could use a reducing furnco or modified glue reducer on the pump end. Would you just let the tap end sit inside the pipe and figure most of the water will go into the main?

Intplm.

You would only need to adapt, or install at your end, or that is the pump side and send the discharge, smaller pipe, open and dead-ended to terminate when it finds the main to discharge into.

A proper fit at the pump discharge should do the trick.

From here I cannot be too specific of course, but if you have the room, it can be do-able.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1802794#Comment_1802794

Michigan

Mad Dog_2

Upper or Lower Peninsula? Mad Dog

mattmia2

https://forum.heatinghelp.com/discussion/comment/1802943#Comment_1802943

Lower. Southeast. Ann Arbor. EN82