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  • Twin Line gas supply or 2-3 regulators?

    Twin Line gas supply or 2-3 regulators?
    I've seen various threads about losing pilot lights on water heaters etc whilst home-fuleing via a compressor. I get this problem. The solution appears to be a twin-line supply, thus 2 x gas meters, each feeding their own segment. In the UK I'm not likely to be able to get such a facility installed easily. Now it occcurs to me, assuming the pressure is high enough, would 2-3 regulators after one meter be pretty much the same thing, and do the same job? A pilot only needs to stay lit, will this work?

  • #2
    Re: Twin Line gas supply or 2-3 regulators?

    Much of your question relates to supply. What is the pressure supply? Here in the US the supply may be regulated to 6" or 7" water column at the meter or come in at 2 psi and regulated before the appliances. (one regulator or multiple) If regulated at the meter to 6" or 7" wc the gas company can change the regulator to 2 psi and then you need to regulate it down for the appliances. For a new line to the garage you could tap off from ahead of the 6" wc regulator and have another regulator at the garage.

    If you are stuck with 6" or 7" wc be very diligent on the flow calculations to make sure the supply is adequate.

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    • #3
      Re: Twin Line gas supply or 2-3 regulators?

      You need to be sure that the meter and regulator are sized for the load. A home meter can be as low as 150 cubic feet per hour, although most are good for from 200 to 275 CFH. If you have an instantaneous water heater it can quickly starve your supply. This is why you need to include your gas utility when installing a home fueling unit. Be careful trying to upgrade your pressure to 2 PSI, many utilities requier a welded house line at 2 PSI and above.

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      • #4
        Re: Twin Line gas supply or 2-3 regulators?

        Thanks for that, erm, not as simple as I'd hoped, but in truth I'd suspected it wouldn't be. I've since played about with it to recreate the issue, 'on-cue' as it were, and now see the complete problem.
        The thing is, in my situation all appears rahter odd. I have 3 x appliances running on my supply. I can run my gas tumble dryer, my cental heating boiler, and my homefuel off my supply, all going 'full-chat' no issues at all.
        But here's the odd bit, if I shut down my compressor, if my boiler is not running at full throttel, this cuases my boiler pilot light to 'flicker & hunt ' for a few secs, and then go out. To be clear, it'll only do this if its not being called to heat, thus if the boiler is at full-throttle, burning to heat my home, and I switch off my compressoer at this moment, no issue, but if the room stat is not calling for heat, thus we have only a pilot, because it has only the pilot going, it 'hunts' and then goes out. The tumble dryer has its own auto-ignition (no permanent pilot) so if this is also happening on the dryer, i'll see not it because it relights everytime it calls-to-heat.

        Alos having gone out, it's a b*(rd to light, so I find the best way is the put he compressor back on or the tumble dryer, and it gets rid of the air to amek the pilot light again.

        Thus as far as I can work out, it is the compressor shutting dwon that causes the issue? Odd, surely it would be at this point that we have more gas on tap not less? If it was starting the compressor causing it I'd get it, but shutting down?? - this has me flummoxed. It looks liek my compressor creates a vacuum in hte pipe on shut-down, or I'm thinking we have a regulator issue or am I over-thinking thsi one?
        Last edited by BritCNGUser; 12-28-2012, 07:11 AM.

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        • #5
          Re: Twin Line gas supply or 2-3 regulators?

          @Brit,
          Couple of things you can consider: When your pump shuts own, you mat be getting a small surge in pressure at the pilot, causing it to 'flare' or stand away from it's base, then it tries to recover. Putting a regulator on the boiler itself may help buffer that issue. The other thought is that a standing pilot requires a 'thermopile' which is the safety device that signals the pilot is lit. When that misses flame, it cools rapidly and shuts off the gas supply to the boiler. You may just have a weak thermopile needing replacement,or you may be able to adjust the position of it slightly further away from the pilot so that it stays in the flame at shutdown.
          '11 Fusion Bi Fuel & FMQ2-36 VRA
          (Former owner '09 Civic GX)

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          • #6
            Re: Twin Line gas supply or 2-3 regulators?

            If your compressor line is coming off the end of your appliances line you should probably separate the compressor line by teeing it off the main line ahead of the appliances.

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            • #7
              Re: Twin Line gas supply or 2-3 regulators?

              A little more information might be helpful. What is your total BTU load? IE each appliance has a BTU input rating add them all up, including the home compressor. How is the compressor tied in? Generally they will be close to the meter. Is vent on your regulator clear? Sometime they get painted over or plugged in some way. If this happens the regulator won't react properly.

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              • #8
                Re: Twin Line gas supply or 2-3 regulators?

                Thanks for your help.More info: I 'm pretty sure I have the grunt in terms of capacity, because wtih all three applainces on they work without remark. In fact without the tumble-dryer running, thus two appliances only, I still get the pilot snuffing, so I'm pretty sure, it is not a capacity issue. It has happened again this am, and the boiler is a 'B*&%£ @ to light yet again. I stongly suspected air in the section of the pipe leading to my boiler. I fired up my tumble-dryer to evacuate the pipe and then it worked fine. That to me confirms I had air in the pipe. In the UK we use KW/h rather thatn BTu and capacity is 75Kwh thru' this meter. About 250 cu feet in US measure. Dryer is 6kWh, boiler is 17Kwh, and the compressor (I'm not sure of but does my 8GGE tank in 3 1/2 hours, it's a Coltri 5 so by my calc that is 50kW). So with the Coltri running and only a pilot wanted from the boiler, I should be fine. Agreeed all told I am on hte limit of capacity of my meter with all three throttled-up, but that is not he issue.
                Pipe daims. are good. I'm running 22mm (UK std size) to everything from the meter, and spur out at 22mm to each item. Plenty for all I think. so pipe capacity is unlikely to be the issue. I hadn't thought it could be the thermocouple, and will look at this, and the flaring noise I hear, (the pilot goes noisy before snuffing) could cause the thermocouple to be flickering out of the flame, in doing. I hadn't consdered this.

                Only htis does not in my mind explain why i'm left with an empty pipe to evacute before I can relight. The thermcouple would shut the gas-valve, no? Anyone have a handle on what might be happening?
                Last edited by BritCNGUser; 12-29-2012, 08:56 AM.

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                • #9
                  Re: Twin Line gas supply or 2-3 regulators?

                  Perhaps you would consider getting a qualified gas person on site to calculate, evaluate and recommend a path to correct the issue(s).

                  I very highly doubt that you are introducing air into the gas system, but if you think you are, STOP, shut it all down and get professional help immediately. Air in the gas line is very dangerous, no gas system pressure should ever be negative to the atmosphere.

                  The life you save may be your own.

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                  • #10
                    Re: Twin Line gas supply or 2-3 regulators?

                    There should never be air in your gas line, the gas system is pressurized. I would contact your local Gas utility and have them inspect your system and appliances. For a Fuelmaker that diameter of pipe would be undersized, but I know nothing about the compressor you are using. I have no idea what kind of water heater you use, but I have a feeling that could be where the problem lies.

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                    • #11
                      Re: Twin Line gas supply or 2-3 regulators?

                      Is the 22mm OD. ? , If so, you are way undersized for all 3 appliances, and that would be maybe adequate for the coltri alone, as it can use a nominal 300 cfh. How many meters (distance) is the furthest outlet from the gas meter/ regulator ? You need to stop using the compressor until this situation is resolved. Get your gas supplier to the site to help. The poss. of an explosion or fire is not worth the risk.
                      Last edited by Lakewood90712; 12-29-2012, 11:42 PM.

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                      • #12
                        Re: Twin Line gas supply or 2-3 regulators?

                        What pressure do you run in the uk on the low side of the regulator we here stateside run about 7 inchs a friend had a coltri and had to run a seperate regulator and meter for it and a pluse tank as it would suck all the piilot lights out with a 1 1/4 line but it sure is a nice compressor

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                        • #13
                          Re: Twin Line gas supply or 2-3 regulators?

                          I run 22mm OD.UK meter spec allows allows 7 CFM whereas Coltri pull 5 CFM. Only 2CFM left for everyhting else so it is tight.
                          Interesting what you say of the 1 1/4 pipe. That's 31-32mm (ish) diam. Makes 22mm seem samll, but I suppose its about pressure as well and 22mm runs all three no issue.

                          And a pulse tank? What's that for [heaven's] sakes! Never even heard of such a thing, I'm curious, What's the &$£@ is that when its at home? I'll Google it. I'm guessing a reservoir

                          Something somewhere is not right, and in this case, I hate to admit it, but I can see shades of the old adage, "A little knowledge is a dangerous thing".
                          I suspect the issue is not one of capacity, but of the heater itself. Lest it be a case of "Stupidity wins fair maiden" I really should get a proepr inspection by someone who actaully knows thsi stuff. My problem is that in the UK, no one does. By this I mean, whilst there is no shortage of gas engineers, as soon as you mention CNG compressors, thye'll run screaming. I had trouble getting anyone to install that gas fired tumble dryer.

                          CNG?l, no one has heard of such a thing, we have less than a dozen Homefills in the couintry. Compared to the UK, CNG stateside is running rampant, dare I say sweeping the nation, on CNG the UK runs behind jsut about everywhere. It is why I am on this US based site, at least when i say Homefill, you first thought is not to say "Why?" and questionn my sanity!
                          Then again, if I don't get this current issue sorted, you might have reason to...

                          BTW: i'm seeing what you have to pay for a Coltri 5 your side of hte pond. Here I paid, what converts to USD6800 all in. Not cheap, but for waht they are... fair. They're lots more for you, and I can't see why that should be.
                          Last edited by CNGLO; 01-01-2013, 02:56 PM. Reason: TOS language violation

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                          • #14
                            Re: Twin Line gas supply or 2-3 regulators?

                            well my friend across the pond a pulse tank is to stop pulses from damaging the regulator . when the piston of your first stage gos down it pulls the gas in causing the regulator to open than it reaches the bottem of the stroke and the valve closes and the gas stops and the rubber in the regulator slams back and closes the regulator. at 500 rpm this is happening 500 times a min so you can see that the regultor parts would wear out very rapidly so by putting a tank in line with the compressor inlet and the regulator outlet it smooths out the pulses. it could be that the pulse of high pressure when the compressor cuts off is blowing the pilot light out I run a 50 gallon pulse tank with a 15 cfm compressor so I think if I was wearing your shoes with a 5 cfm compressor I would put a 20 gallon tank in the line right before the compressor it must have a seperate inlet and out and they should not be across from each other a few inches apart on the same end seems to work well. good luck cowboy

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                            • #15
                              Re: Twin Line gas supply or 2-3 regulators?

                              Hallelujah! before coiming back to thsi thread I googled the function of a surge tank and I nearly had my my head on it, there's not much I could find, then (Cowboy, thanks to your reply, now) I see the light. I'm sure this is a big part of my problem. I've an electroniucs backgound and thiis 'surge tank' is like shoving a stonking great capacitor into a circuit, to smooth out a spiking supply. Not sure whre I'd get such a thing, can't imagine they're exactly common-or-garden here, so I'm wodering if I can get hold of a heating boiler pressure vessel beefy enough to do the job. I'll start looking. Thanks to you, I reckon I'm on the scent.

                              I found this:

                              http://www.youtube.com/watch?v=kzSiL3h2pUU

                              He uses a pulse tank too.
                              Last edited by BritCNGUser; 01-03-2013, 05:11 PM.

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