Valve manifold with expansion couplers .... good or bad?

Discussion in 'Irrigation' started by wolfdown, May 30, 2012.

  1. wolfdown

    wolfdown LawnSite Member
    Posts: 9

    I just replaced a set of 1" valves and was surpised to find expansion (telescoping) fittings connected on the output side of the valves. This actually simplified a lot of the work to change the values out. I had to extend the telescopes to fit my new vavles, but it was relatively easy with some 2" lengths of PVC and a standard coupler.

    I've been doing some research, and I haven't seen anyone recommend this type of setup. I'm worried that this is actually a bad design. From what I can tell, the telescope fittngs will put a lot of lateral pressure on the PVC line and valves when it is pressurized. Can anyone tell me if this is OK to leave as is, or should I try to "fix" it.

    So far the new valves are working really well and I imagine the system has been running for 10 years or more with the original valves that were replaced ... so more curious about this type of design, and how common it is. Thanks.
     
  2. mitchgo

    mitchgo LawnSite Silver Member
    Posts: 2,774

    As long as the slip fix is fully extended after the repair they are fine on lateral lines.
     
  3. wolfdown

    wolfdown LawnSite Member
    Posts: 9

    ah .. correct. I see now that I shoudl have done the final solvent step on the telescope ends with everthing else in place :(

    Unfortuantely, I did not do it that way. I wasn't aware of the issue at the time of the fix. So as it stands, I could go back and repair 2 of the 3. I used up the last amount of the telescope of the third one. So I either have to replace whole telesecope body and slide, or find and identical slide-end (probably hard to find since its 10 years old, yes?)

    So how bad is it? all of the pipes are burried, and don't seem to flex or leak when the pressure is on. :wall:realmad:
     
  4. If the pipes run straight and don't come to any fittings leading to laterals for 10'+ you are probably okay. I wouldn't worry about it. Just chalk it up as a learning experience.
     
  5. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Telescoping pipe fixes have no place in a manifold. Get some unions and do it right.
     
  6. wolfdown

    wolfdown LawnSite Member
    Posts: 9

    @FIMCO-MEISTER: Unfortunately, there are elbows shortley before or after every telescope fitting.

    @Kiril: Sounds like good advice. It was the original design, so I'll look into to see if I can change it somehow.
     
  7. Dig it up and send us a pic.
     
  8. wolfdown

    wolfdown LawnSite Member
    Posts: 9

    See pics. I got the unions today. What side should the compression nut go on? Valve side, or the downstream pipe?

    IMG_5770.JPG

    IMG_5771.JPG

    IMG_5772.JPG
     
  9. Downstream side. Cut the slip fixEs out and dig back some more. I could do that repair with 2 coupling, 2 maleadapters, and 4 elbows. Unions aren't all that necessary here. As for the straight shot pipe use a union and a male adapter on that one.
     
  10. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Definitely. No need for a union or SF in the case of the ones with the ells.
     

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