Topic: a bit of plumbing help?

[calj737]

Backflow preventers are usually only installed in potable systems, not sewer. The way modern sewage is designed is to equip homes with above line cleanouts. This is coupled with an atmosphere vent generally prevents these backups anymore. That, and better designed systems...

[vames]

My house was designed and built around 1920, so I doubt I have any modern design of the system. But all of my drains work well and we don't get sewer backups, at least in the five years I've been there. The vent stack is about 10 feet away near the washing machine.

To test the viability of the cleanout, I sprayed a hose into it full strength for about 20 minutes. The water just drained and drained and drained -- no sign of hesitation. The way I'm envisioning, I think the P-trap will keep the sewer gases contained like it should. I'm pretty sure it will all work out. At any rate, I'm not finishing the basement until spring, so I'll have a few months to make sure it doesn't get wet or gassy down there.

[Duke McDukiedook]

My county installed backflow valves on the street elbow on houses in my old neighborhood due to backflow problems and would send out a yearly maintenance bulletin to all the people who had them. I never had any problems with a sewer backup at that house but had neighbors that did have sewer backups when we would get heavy spring rains.

[calj737]

My county installed backflow valves on the street elbow on houses in my old neighborhood due to backflow problems and would send out a yearly maintenance bulletin to all the people who had them. I never had any problems with a sewer backup at that house but had neighbors that did have sewer backups when we would get heavy spring rains.

That's a situation caused by storm drainage mixing with sanitary sewage. Many old municipalities used this mixed system once under the street. That's been systematically re-engineered during recent decades and no longer is considered acceptable.

Waste sewage is contained and run to county waste treatment plants to sanitize the sewage before its returned to storm drainage systems. Storm drainage runs to natural impoundments whenever possible to allow filtration and percolation back into the groundwater.

[Don R]

Many of the brass plugs are 3 1/2" this is done to keep people from hooking onto it. An air gap is mandatory in any event. It may work without a proper vent per code but if you sell the house it may be caught during an inspection.
 

[vames]

Many of the brass plugs are 3 1/2" this is done to keep people from hooking onto it. An air gap is mandatory in any event. It may work without a proper vent per code but if you sell the house it may be caught during an inspection.
 

I just checked and holy crap it is indeed 3 1/2" (looks to be NPT) but can't be sure. At any rate, I don't think there is any such thing as 3 1/2" PVC to thread into that hole. If there is a solution that exists, Grainger will have it. I'll call them tomorrow.

[madmtnmotors]

Would it be easier to tee off the washing machine drain?

[vames]

Would it be easier to tee off the washing machine drain?

Yes and no. While it would be super simple to just go into the slop sink that the washer drains into, I'd have to run the discharge tube through a couple of walls to do it. This cleanout is literally zero feet away from where the softener is going to go. 

I've discovered cast-iron bushings that bring 3 1/2" down to 3", so I think it will work out.

[754]

How big is the discharge pipe ?
I had started to plumb in a vintage water fountain in the shop, it was near the cleanout, so my plan was to drill/tap into the square nut portion...(to drain the excess water) ....
 Cant remember but I think there was room for a 3/4 inch pipe thread..?
 Might be a option if you have the pipe tap..

[vames]

Drilling and tapping into the ductile iron or the brass cap was one of my initial ideas. I'm sure it would work, but it wouldn't look remotely to code. The way I'm going to do it will look (and act) very much code-compliant. That will help in case I do ever need to have an inspector down there.

[Kevin D]

Vames , I got this 3 1/2 - 3" bushing from the plumbing supply $20? Black iron, Thailand. the big box stores didn't have it. The counterman gave me a lecture along the lines of what Don said. Anyway I use it for my emergency sump pump temporary installation. I have a water powered sump pump to use when the 120VAC is out.

Edit:  sorry I forgot to attach the photo.

[vames]

Vames , I got this 3 1/2 - 3" bushing from the plumbing supply $20? Black iron, Thailand. the big box stores didn't have it. The counterman gave me a lecture along the lines of what Don said. Anyway I use it for my emergency sump pump temporary installation. I have a water powered sump pump to use when the 120VAC is out.

Yep -- same here. No 3 1/2 - 3 bushing at Home Despot, but a real plumbing supply place near me has them. Clearly it's not 100% code to do it, but I am preserving the clean-out access and function, so I should be fine. And it will look super pro.