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Thread: Need Some Advice for an Upcoming Locate

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    Default Need Some Advice for an Upcoming Locate

    Hey all, I am a newer locator and brand new to the site. I have an upcoming locate that I wanted some advice on. I am a private locator with a job involving large diameter (14"+???) steam pipe and 2 chilled water lines. They run between 2 buildings, buildings are ~30-40 feet apart, the contractor is putting in a building connector hallway and needs to know where these buried lines are. I only have a 5" clamp so I thought I would give my first try at direct connecting to any valve or fittings that are in place and otherwise having the insulation stripped for access to create a makeshift larger clamp.

    I guess my questions are:

    (1) what is the best way to make a larger clamp; using hose clamps and directly connecting to the driver nut? running wire around the pipe then direct connecting my leads to that wire? Would insulated speaker wire be worth it, or should I try like uninsulated bailing wire? I figure it might be my best method getting my signal onto the pipes. they are 10' in the air on the ceiling and with that short a run I don't want to just drop the box (they are also suspected to be at least 10' deep).

    (2) I thought about trying to do this on both ends of the pipes. I really don't want to fight to get a ground in the basement and outside is all pavement. I have never done a closed loop like this, but my novice thinking says in theory it should work???

    Thank you all for reading!

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    Mke
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    Default Re: Need Some Advice for an Upcoming Locate

    Quote Originally Posted by SubterraVT View Post
    Hey all, I am a newer locator and brand new to the site. I have an upcoming locate that I wanted some advice on. I am a private locator with a job involving large diameter (14"+???) steam pipe and 2 chilled water lines. They run between 2 buildings, buildings are ~30-40 feet apart, the contractor is putting in a building connector hallway and needs to know where these buried lines are. I only have a 5" clamp so I thought I would give my first try at direct connecting to any valve or fittings that are in place and otherwise having the insulation stripped for access to create a makeshift larger clamp.

    I guess my questions are:

    (1) what is the best way to make a larger clamp; using hose clamps and directly connecting to the driver nut? running wire around the pipe then direct connecting my leads to that wire? Would insulated speaker wire be worth it, or should I try like uninsulated bailing wire? I figure it might be my best method getting my signal onto the pipes. they are 10' in the air on the ceiling and with that short a run I don't want to just drop the box (they are also suspected to be at least 10' deep).

    (2) I thought about trying to do this on both ends of the pipes. I really don't want to fight to get a ground in the basement and outside is all pavement. I have never done a closed loop like this, but my novice thinking says in theory it should work???

    Thank you all for reading!
    Hospital?

    I've actually been in a situation close to the one you have described. What Type of equipment do you have at your disposal? 810, RD, Vivax, pipehorn, etc...?

    Depending on the type of equipment and the type of pipe you are trying to locate you have a couple of options.

    What I used to do with my 810 was connect to valves and other features. If these features were not useful or not available use a bungee cord and wrap it around the pipe till it was tight and then I would slide the direct connect under the pipe to hold contact. As for the ground, the 810 is pretty forgiving for crappy grounds so I would bring my manhole hook and lay it on the concrete floor and ground to that. The bad part of this is that if you are using different piece of equipment, the availability of a good ground will give you poor results. The other thing you may run into is, some mechanical joints will kill tone. Higher frequency locators sometimes can jump these signal gaps, but I've ran into situations where it wasn't working. Also understand, because the conductor is of a larger diameter and is speculated to be @ 10' your signal, if you get one is going to be slow and wide. Walk the area slowly....Preferably with an analog receiver.

    As for creating your own "Clamp". There is a theory out there that you can take your direct connects and just wrap it around the pipe several times and then clip it onto itself to induce a signal into the conductor. Just know this probably won't work with the lower frequencies. I've used it on large conduits and it's worked, but haven't had good results with water lines.

    The other thing that I would do is walk between the buildings with a Split box. 30'-40' between buildings should give it enough room to work without interference... as long as there isn't too much running through that space. The Split box will give you a wide signal, but it should peak on top of the utilities depending on their spacing.

    I was locating a school one time in Aloha Oregon and nothing was able to locate the water line (18" DIP @ 15' down). The line was between a 17' retaining wall and the main school building and they were putting in a new storm line. The only thing that located the line was the split box. Due to the depth it was a light signal, but it still peaked. The crew called me back later in the afternoon to let me know that I was right on. (Knowing that when you dig down to 15' right on is +/- 2')

    Let us know the spacing between the lines and what equipment you are using. There is a couple other things you can try but it would depend on any cross bonding of the pipes in question.

    mke
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    Default Re: Need Some Advice for an Upcoming Locate

    Thanks for the response! I am using a Vivax-Metro VLOC-5000 w/ a 10-watt trans. The lines are probably 12"-16" if I had to guess from looking at photos, pretty close to each otherimg_1401.jpg

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    Default Re: Need Some Advice for an Upcoming Locate

    Should be able to direct connect to the pressure gauge on the left. Any idea what the capped off pipe is? Maybe run a locatable rodder or fish tape down it.

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    Mke
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    Default Re: Need Some Advice for an Upcoming Locate

    Quote Originally Posted by orangeboots View Post
    Should be able to direct connect to the pressure gauge on the left. Any idea what the capped off pipe is? Maybe run a locatable rodder or fish tape down it.
    Just be careful when opening it. if it is a sanitary line, or a storm line that has any water being retained, you could be screwed. The only good thing is it isn't above your head. (Long disgusting story filled with lots of hot showers and shots with big needles).

    mke
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