Tapping Galvenized

Discussion in 'Irrigation' started by trimmer, Jul 19, 2001.

  1. trimmer

    trimmer LawnSite Senior Member
    Messages: 293

    I am about to put a sprinkler system into in older house. My problem is the main water line is galvenized pipe with a 6" piece between it and the meter. I have never run into this problem so I don't know how to confront it. How do you tap into it to get your water source?
  2. racerdave

    racerdave LawnSite Senior Member
    Messages: 260

    IMO you should replace the galvanized pipe with either copper or plastic pipe. That old line is not going to last, let alone getting you thru this project. This kind of pipe corrides from the inside out. If you can get it apart you will see that the water flow is highly restricted. which will cause problems with the irrigation and household water suppies.

    If you haven't completed your bid, you may want to add the cost of replacing this line. If you have already started the job, try to talk the homeowner into the additional cost of the pipe. After all, you will be trenching their yard up anyway, they will be glad you are doing this now instead of later.

    good luck,
  3. greasemonkey

    greasemonkey LawnSite Member
    Messages: 57

    most lenghts of galvanized pipe are male threaded on both ends, thus if you try to remove a section, you will end up tightening one end as you loosen the other end. The solution is to cut the pipe in the middle with a sawzall or what have you and to replace that section with copper pipe and the "t" that will go to your sprinkler system. You have to use brass nipples between the galanized pipe and the copper otherwise you will have galvanic corrosion which is the slow but steady electrolytic decay of the pipes as the electrons in the dissimilar metals try to figure out where to go. The brass nipples help to kind of smooth everything out because it has properties common to both the copper and the brass. don't forget to take into account that the galvanized main may provide much less flow than a copper main of the same internal diamater due to the tendancy of galvanized pipes to develop scale.

  4. trimmer

    trimmer LawnSite Senior Member
    Messages: 293

    There is 80 psi of preasure but somehow someone has hooked up pvc to the galvenized directly.
  5. racerdave

    racerdave LawnSite Senior Member
    Messages: 260

    Are you saying that it goes from the main to plastic to gavlanized pipe?

    If so, this indicates to me that they are having problems with this pipe. I believe it's design life is about 25 years.

    To get the plastic to it . It must have a threaded collar attached to one or both ends of the plastic. These collars where probably screwed to the Gal. pipe and the main then the plastic was glued into them.

    I need more info:confused:

  6. trimmer

    trimmer LawnSite Senior Member
    Messages: 293

    Coming from the house is galvanized, then there is a about 6" piece of pvc, then the meter.
  7. gusbuster

    gusbuster LawnSite Bronze Member
    Messages: 1,932

    Get rid of the galvinezed pipe!
    Great info from previous posters.

    I would never suspect a municipality would of done this repair in the first place. Get some brownie points for doing the job right. If you don't want to get to involved, I would do as greasemonkey suggested.
    Good luck
  8. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Messages: 1,712

    If it is galvanized pipe from the main in the street to the meter, either have it replaced as part of the job or don't do the job. The water in our area can really grow this stuff shut on the inside. It's also a killer on friction loss even when clean and new.

    Don't go there.
  9. KD'sLawns

    KD'sLawns LawnSite Member
    Messages: 160

    I agree with everyone else on this subject, try to talk the homeowner into replacing the main line all the way to the hot water heater. It may not necessarily increase their usable volume in the house as the output lines from the heater are probably 1/2" galvanized and will have scale build up and corrosion. If the homeowner declines the offer to replace, and you still want to do the job. Cut the main line between the plastic and the galv. pipe and install your water supply tee between them. The O.D. of your galvanized and your plastic should be the same so you can use a line repair clamp with a tee in it. The reason you put it between the existing lines, is that you will get your unrestricted flow out of the plastic to supply your sprinklers. Hope this helps!

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