Announcement Announcement Module
Collapse
No announcement yet.
rust in gas pipes Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    I am only saying that if it was my house i would hook my air compressor up and blow the system out that way because i do not think that this will in anyway cause further problems.

    Yes, I would use nitrogen because I have seen first hand that it works better at drying out pipe lines.

    Bob everytime you do a gas instal do you pressure test it with nitrogen or do you use your air compressor?

    No, but the problem that this whole thread stems from is not present in the majority of installations. The difference between pressing up the line for a drop test and that of clearing the line out to remove rust and scale and moisture is that the latter pumps many cubic feet of air through the piping, where the former is only injecting a small amount of air into a closed system, enough to raise the pressure for a test but not even equal to the volume of the line, so very little moisture would or could be left in the line from my way of thinking.

    I don't do residential installs, I do little residential work at all for that matter, mostly commercial, industrial, or utility work and new work at that.

    When we are running a gas line it is usually a 4", 6", or larger main into the building. On these systems we have used air to test but they are new so the moisture problem is not present. Last job I did with any gas line work was a big kitchen in a hotel, we tapped into the existing 6" line and brought 3" into the new kitchen. The tap was done after midnight and in a couple hours the existing kitchens were back up and running before 5 AM the next morning making breakfast. We tested the new section with air when it was ready (about 250' of 3" on down to 3/4").

    If it was your house would you buy nitrogen or would you use your air compressor?

    As I said, if I was only looking to press up the line for a test, I would be happy using compressed air. But to try to clean a small bore line I would use nitrogen, though I will admit that compressed air would be better than doing nothing at all.

    Depending on the condition of the pipe and what was captured in the rag during the blow down I would have to consider that maybe the pipe is corroded beyond a safe level (minimum wall might be violated) and replace it all. Without a UT (Ultrasonic Test) or other NDE of the entire line how could you know that there are not low areas where water has collected and over the years eaten most of the way through the pipe wall?

    The moisture problem could be in the Gas Co.'s line out in the street somewhere. If when the pipe is disconnected from the meter and isolated from the utility lines there is evidence of moisture at that point it might pay to have the utility look into the problem too. Because if there is moisture present there then it seems to me it must be coming from the utility side of the meter.
    ---------------
    Light is faster than sound. That's why some people seem really bright until you hear them speak.
    ---------------
    “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
    ---------
    "Its a table saw.... Do you know where your fingers are?"
    ---------
    sigpic http://www.helmetstohardhats.com/

    Comment


    • #17
      ok, i wasn't going to ask any more questions .. but very curious to know what the average life of a gas pipe is anyway? The house that i am talking about was built in 1880 in baltimore city .. not sure what year they started having gas (any idea anyone?) but all homes in the city should have gas pipes with the same age ... is it possible that all Baltimore City homes have original gas pipes? .. i am just wondering if the gas companies have any responsibilty to inform and educate homeowners regarding the age of their homes and the gas pipes in them .. at a minimum, i would like to think that they change the meter/regulator after so many years in service, do they?cause most people who live in this area are very poor and uneducated

      Comment


      • #18
        They can last a long time. I had a house in the 1980's that was piped for gas lighting when it was built in 1905. That pipe was still in service when I bought the place and when I sold it 8 years later, though I had disconnected all the red brass piping for the lighting, and was using only the 1-1/2" main to feed the clothes dryer, water heater, and the stove, which were the only two gas appliances we had. The reason the line into the house was 1-1/2" is because the old gas light system was very low pressure, only 2" WC is what I was told by some of the old timers I have worked with, so they needed the larger diameter for the volume into the house.

        When the house was built it was also wired for electricity, but the service and whole concept of electric lighting was so unreliable and intermittent that gas lighting was also installed, and combination gas/electric fixtures to boot just to make things interesting
        Last edited by Bob D.; 10-05-2006, 10:24 PM.
        ---------------
        Light is faster than sound. That's why some people seem really bright until you hear them speak.
        ---------------
        “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
        ---------
        "Its a table saw.... Do you know where your fingers are?"
        ---------
        sigpic http://www.helmetstohardhats.com/

        Comment


        • #19
          "with nitrogen you have to be careful as this will displace oxygen and possible cause a problem to your health."

          Oh, I forgot to respond to this comment.

          Since nitrogen comprises about 78% of the atmosphere I don't think we are in any danger of suffocating from the use of a bottle or two for a job like this. If we were working in a confined space or one in which it might be possible (say a small basement with little ventilation and/or limited access) to displace enough oxygen that we lowered the O2 level below 19% then we might have something to worry about and it is true that this situation should be considered and evaluated as it is possible. If the work were different and another gas was being used, say Argon to purge a pipe during welding, and the job required large amounts of gas, then it would be a totally different story and the likelihood of creating a depleted O2 environment would be much more probable.
          ---------------
          Light is faster than sound. That's why some people seem really bright until you hear them speak.
          ---------------
          “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
          ---------
          "Its a table saw.... Do you know where your fingers are?"
          ---------
          sigpic http://www.helmetstohardhats.com/

          Comment


          • #20
            Removes condensed moisture, oil aerosols
            Also particulates from compressed air lines
            Will provide clean, dry, oil-free air
            Replacement filter for M-60 is M-723
            One-year warranty


            Bob I feel no real nead to argue anymore I agree that nitrogen is better than compressed air. Cost over value? (yes i know there is no price on saftey) And i agree that he should look into the integrity of the pipes. But with an air filter is compressed air possible up to your usable standards?
            I am not trying to be a a** i am just throwing it out there.
            Last edited by PLUMBER JAY; 10-06-2006, 12:37 AM.

            Comment


            • #21
              Jay, I don't see us as arguing at all, this is a discussion of opinions and ideas from which hopefully we are all learning the pros and cons of each others views and beliefs as to what is 'the best' way to approach this problem, at least that is how I am taking it.

              When you start hurling insults my way then we are past the discussion stage. I don't see this going or intend on taking this thread there; do you?
              I've been on enough jobs and run enough crews in 29+ years to have heard it all, so anything anyone might say in a thread here is not going to phase me. They're just words.

              You posted some info on a filter for an M-60, but I think some data is missing. Is this some type of inline filter for use on a compressor? If so, yes, they will certainly help. You can use air to do the job. You could also use a combination of the two to save money. Blow out the rust and scale using your air compressor, then follow with a purge of N2 at a low flow rate to dry out the line.

              This is what the phone company does on some of their older trunk lines. You may have seen along the side of the road chained to a pole a bottle with a regulator on it and a tube running up the pole. This is tied into a truck line that the outer casing has been compromised on, mot times by squirrels who like to chew on the jacket or lead casing used at the splice points. Once the violate the integrity of the casing water gets inside when it rains. The old wires were wrapped with a paper insulation that would soak up the water and sometimes cause cross-talk between wires or shorting of wires and a dead line. So they would find the leak and patch it (using wiping solder years ago or more environmentally friendly methods now-a-days) and then pump a bottle or two of nitrogen through the casing to dry it out.
              Last edited by Bob D.; 10-06-2006, 09:29 PM.
              ---------------
              Light is faster than sound. That's why some people seem really bright until you hear them speak.
              ---------------
              “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
              ---------
              "Its a table saw.... Do you know where your fingers are?"
              ---------
              sigpic http://www.helmetstohardhats.com/

              Comment


              • #22
                Bob i agree, I just did not want to come across like i thought i knew more then the guys that have been around for a long time.
                The info on the air filter i found somewhere on the net. It was for use on an air compressor and i posted it just to help get a point across.
                I would have to agree that a combination of compressed air and nitrogen sounds like a pretty good solution.

                What about the other pros out there what route would use guys take?if by some chance you see a problem like this one day.

                Comment


                • #23
                  first off i would air test the entire system for leaks, using an air compressor or co2 bottle. (never had a nitrogen bottle. plenty of co2 bottles)

                  if it held test, i would then use the compressor to blow out the dirt, rust or moisture. if it had alot of moisture, i would hook a shop vac. to the line to either blow or suck the line dry for an extended period of time. air flow is what dries lines. nitrogen is just a dry inert gas. it is too costly to continue running bottled gas into the line to dry or purge the piping. a vacuum will do this for pennies of power

                  that's my opinion.

                  what do you guys think

                  rick.
                  phoebe it is

                  Comment


                  • #24
                    Originally posted by PLUMBER JAY
                    Bob i agree, I just did not want to come across like i thought i knew more then the guys that have been around for a long time.
                    The info on the air filter i found somewhere on the net. It was for use on an air compressor and i posted it just to help get a point across.
                    I would have to agree that a combination of compressed air and nitrogen sounds like a pretty good solution.

                    What about the other pros out there what route would use guys take?if by some chance you see a problem like this one day.
                    Plumber Jay,

                    I normally use nitrogen to test gas lines out of force of habit. I spent alot of years piping aerospace plants and government building where this was the specified testing proceedure. I continued to use it, if it was available, because I realized this was actually a better system.

                    Do I recommend that all systems be tested this way? No.

                    If I repiped my own house's gas system I probably would use air. My gas system would consist of less than 100' of 3/4" pipe.

                    I simply recommended it in this case because Switchex has an obvious rust problem.

                    As far as your concern about N2 in the house, you could blow the system out from the inside to the outside.
                    the dog

                    Comment


                    • #25
                      i am learning so much here and glad to have this topic posted. Thanks all …

                      I had called BGE long time ago about the problem .. i spoke to a lady and explained the "rust in the pipe" problem .. I don't think she had any idea about what i was talking about .. and basically said that if you have rust inside the pipe, it is your problem and you need to call a plumber . .at that time I wasn't thinking about the cause of the rust, which is moisture that most likely came to the pipes with the gas (i think that's what u all are saying) .. if that’s the case, every one in the city, or at least everyone near my block, is effected ... i will call them again and see if I can find someone more knowledgeable .. But don’t gas companies check for these things regularly? I mean, this could be effecting many homes and casing a very dangerous situation for all ...

                      Comment

                      Working...
                      X