Backflow valve on water supply for cleanout

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Cellomangler, Nov 15, 2008.

  1. Cellomangler

    Cellomangler New Member

    Messages:
    3
    I've got a small building with my main sewer drain line running underneath and the only clean out accessible is on this high side with the city main line on the opposite side of the building -about a 40 ft run. I'd like to install a permanent water line running into the cleanout plug so that I can turn a valve just inside the building and flush out my main drain line from time to time. There is a water line just inside the wall that currently feeds a toilet and it would be a piece of cake to put a valve there, maybe a stop and a shutoff, as well as a backflow valve, and run that line to the clean out plug. Closing one of those valves would let the water run out and a back flow valve would prevent the unlikely occurence that sewage would back up into that line - it would rise up through other drains first. Question is.. is it within code to do this... is it most likely safe enough even if not in code... and does anyone make a CPVC half inch stop valve that I could put in the line ? 'Tanks..........
  2. Absolutely no code would allow this,

    and the backflow protection even if it was allowed, would have to be a RPBA due to the extreme hazard.

    An Air Gap would be required to make it safe using an indirect waste or open floor receptacle.
  3. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Yea, what he said....In Spades...
  4. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Thank goodness the question was asked instead of just handymanning it...:eek:
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    backflow

    The hazard is not from the sewer backing up into the water line, it is that the water line could siphon the sewage into your, and all your neighbor's, water line.
  6. Cellomangler

    Cellomangler New Member

    Messages:
    3
    OK, OK, OK... I'm not going to do it that way. But here's my workaround: Where the line would run just inside the wall I'm going to have a total disconnect and separation after my stop valves for the water line. Then I'll have a short hose such as a hot water tank line that I can use to connect up the flush line to the cleanout. I'll also keep the line coming up from the cleanout capped -or put a stop valve on it. I'll design it so that the hose keeps the cover (of the wall cubby space where the lines are exposed) from closing when it is attached so I won't inadvertently leave it hooked up. Now this is really no different than running a garden hose into the cleanout, wouldn't you think...? ..since there will not be a permanent connection.
  7. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
  8. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Main lines do not need to be "flushed out occasionally". You are off track on this. If you want to flush the line, turn on the tub and let it run! Please do NOT try to get involved with connecting water supply to drain. Your inspector will have you for lunch.
  9. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    flush

    The key word in your description is "flush". Flushing a toilet a couple of times will do as much, or more, than your ill advised hose. What you are trying to do requires volume and velocity, things flushing the toilet gives, but not the hose.
  10. Cellomangler

    Cellomangler New Member

    Messages:
    3
    Alrighty then... sure appreciate the honest feedback and additional literature. I won't bother with it. Saves me work and an extra hole in the wall, anyway. BTW, I guess when folks use those balloon things on their garden hoses and stick them way into the cleanout to purge their home system... well even that could be inviting problems...? Cheers.
  11. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Sounds good to me.

    Yes blow bags could be a crossover problem. They are also not a good way to clean a sewer line. Kind of a last resort!
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    blowbags

    Blowbags are used in an attempt to unplug a drain line, seldom to flush them. The water flowing through them is usually a very small volume, otherwise if they did not work, which is usually the case, you would flood the building.
Similar Threads: Backflow valve
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & Backflow valve? Jul 30, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Backflow Valve Advice Aug 31, 2012
Plumbing Forum, Professional & DIY Advice, Tips & backflow valve but still flooding Apr 16, 2012
Plumbing Forum, Professional & DIY Advice, Tips & Are some checkvalves better than others - Water Backflow Preventer Sep 22, 2011
Plumbing Forum, Professional & DIY Advice, Tips & Backflow valves - Why? Dec 15, 2010

Share This Page