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Thread: Delavan Siphon nozzle issue not working

  1. #11
    Quote Originally Posted by Zapins View Post
    Its up in CT. I'll be back late june. I bought some needle valves that I want to try install to control the fuel and oil mix. Might help me get it working.

    Just been a frustrating money sink. I wish one of you oil burner guys could come over and help me trouble shoot it. It shouldn't be this hard to get it working...
    When you figure out the keys to success, write it down for me please. I looked at the delvan stuff when I started this a few years ago, but passed because the kwicky was cheap and well.... KWIK!
    Mine is working well these days, but could be better, yet I refuse to screw with it. Next oil burner I build will be a delevan. I've seen SV's and he melts some big pots of bronze with it. I have a big air compressor and it runs for about 2mins once every 6 or 7 minutes. Can't beat that with a stick!
    Visit me:
    "Sometimes by losing a battle you find a new way to win the war"
    -- Donald Trump --

  2. #12
    Join Date
    Mar 2016
    Tornado alley, USA
    The secrets to a reliable siphon nozzle burner:

    1. Start out using diesel. It lights easily with a cold furnace. Light the furnace by putting a rag with diesel on it in the furnace and lighting the rag. Leave the lid open.

    2. Spray your nozzle into the air (away from anything that could cause combustion), and you should be getting an even atomized spray (photo below).

    3. Use a pressurized fuel tank, and apply 5-10 lbs pressure to the tank. Make sure your tank is rated for pressure, and it is wise to install a safety valve on the tank in case the regulator goes bad (low pressure safety valves available on ebay).

    4. Use one pressure regulator for the fuel tank, and a separate regulator for the compressed air to the burner nozzle.

    5. Use at least 50 psi compressed air to the nozzle. I determined this by running the burner outside the furnace, with an acetylene torch at the end of the burner to keep it lit. Below 50 psi, the burner spewed out small unburned droplets of diesel on the driveway, which began to puddle and burn in a pool. At 50 psi air pressure, the puddling stopped, and all the fuel was consumed in the air with no puddling on the driveway.

    6. Use a needle valve and a ball valve on the fuel line, plus an inline fuel filter. Use the needle valve to calibrate the fuel flow by squirting diesel into a measuring cup, without any compressed air, but only with the 5 psi pressure on the fuel tank, so you get a little stream of fuel coming out the end of the burner.
    Use a stopwatch, and measure the fuel stream for 60 seconds.

    Determine how much fuel you want to burn per hour.
    For aluminum, you may start at 1 or 2 gallons per hour.
    You need a higher fuel flow rate for a lager furnace, and a smaller fuel flow rate for a smaller furnace.

    Assume you want to burn 2 gallons/hour, use the chart below to determine the ounces per minute you need, and then adjust your fuel needle valve to give that amount (using the measuring cup with fuel tank pressure only as mentioned above).
    Tighten the gland nut on your fuel needle valve so that it does not move easily, and don't change the needle valve setting unless you go from melting aluminum to melting iron (which takes a higher fuel flow), or you can increase the fuel flow rate for a faster melt.

    A 1 gal/hr delavan siphon nozzle can be used at 5 or 6 times the rated flow of 1 gal/hr that is stated by the manufacturer.
    All delavan siphon nozzles have a range of at least 4:1.

    6. Use a shop vac, leaf blower, or other suitable blower, and add either a variable speed drive, a blower air outlet valve (can be a 2" PVC valve), or blower inlet damper (I use an inlet damper).
    The combustion air provided to the furnace by the blower must be adjustable.

    7. If you have never run your burner before, you need to find the right amount of combustion air to use with your preselected gallons/hr (in this example 2 gal/hr).
    Put a rag with diesel on it in the furnace with the lid open, turn on the fuel ball valve (don't change the needle valve setting that you previously calibrated, don't touch the needle valve) and simultaneously turn on the compressed air ball valve (compressed air at 50 psi).
    You should get a large yellow flame coming out the top of the furnace. Don't lean over the furnace when started (it goes without saying, but just saying.....).
    Turn on the blower with the air restricted to a very low rate, and then slowly increase the combustion air blower (via damper, vfd, or however) until no more yellow flame comes out the top of the furnace.

    If you turn on too much blower air, you will blow out the flame, and you have to turn off the compressed air, blower and fuel, and start over from the beginning.
    Once you figure out how much blower air you will need for your 2 gallons per hour, adjust your blower (via damper or however) to give a rich burn (some yellow flame coming out of the furnace).
    If all is stable for about 30 seconds, then you can close the furnace lid.

    If you burner goes out when you close the lid, you have the mixture too lean, and you need to start over from the beginning.

    Once the lid is closed, make a final adjustment to your blower to get either a slightly lean, neutral, or slightly rich burn (your choice, I run my with a slight hint of yellow flame coming out the furnace lid so that I am not oxidizing the metal).

    8. The next time you operate your burner, be sure you have not changed your needle valve setting, your compressed air setting (50 psi), your fuel tank pressure (5 psi), or your combustion air damper setting.
    Put the lit rag in the furnace with the lid open, open the fuel and compressed air ball valves, and then start the blower.
    If you have everything set correctly, you never need to adjust any settings again (unless you want to melt iron or something, in which case you have to use a higher fuel flow rate and set your burner up again).

    I have operated my burner for at least 20 melts (since I figured out how to set it up), and have not had to change any fuel or air setting either at startup or during the melt (I don't adjust anything).
    It starts first time every time on diesel, and operates with absolute consistently with any level in the fuel tank, or any tank position/height (I keep my tank at ground level about 50 feet away from the furnace).

    So why do so many people complain so much about delavan siphon nozzle burners not working correctly?

    1. They may be using an air compressor that will not consistently hold 50 psi pressure.
    2. They don't follow the instructions above for calibrating fuel flow first, and then adjusting combustion air flow next.
    3. They continuously change the needle valve that controls fuel flow (calibrate this once and don't change it).
    4. They try to use a ball valve only on the fuel line (you need a ball valve for on/off, and a needle valve for the initial calibration).
    5. They use dirty fuel that is contaminated with water or other stuff, and they don't use an inline fuel filter. Use clean diesel when you are learning how to run a burner, and an inline automotive fuel filter in the fuel line.

    6. If you don't either pull the burner back from the furnace when you turn it off, or keep your combustion air blower running after you turn off the fuel and compressed air ball valves, then you will melt the o-ring in the tip of a siphon burner, and from that point on, you will blow compressed air back into your fuel tank, and your burner will not work at all. This is the number one problem I see happen here with people using siphon nozzle burners.
    I have never melted an o-ring, but I pay attention to what I do after I turn off the burner.

    7. For some reason, I have seen people try to operate a siphon nozzle by randomly jerking around the fuel valve, the combustion air valve or blower speed, no pressurized fuel tank, and they always say "What the hell is wrong with this piece of junk?".
    One guy did all the jerking around with his lid closed and blew the lid about 100 feet up in the air (on this forum), and again said "What the hell is wrong with this piece of junk?".

    Using a siphon nozzle is like driving a car; if you jerk around the brakes, throttle, and shift the gears back and forth into park, neutral, drive and 1st gear while driving, you will say "What the hell is wrong with this car, it works like a piece of junk".
    Of course it does, until you learn how to drive it.

    Learn how to drive your burner and it will work perfectly time after time without any adjustment.
    Ignore this advice and you will have endless problems with your siphon burner, but spare us the grief and don't say siphon nozzles are junk; it just ain't true; too many here use them all the time without problems.

    If you don't have an air compressor, then use a drip-style burner with blower, and preheat the furnace with propane. These work great.

    If you do have a good air compressor in your shop, you may consider a siphon nozzle if you have the patience and desire to set it up correctly.

    There is nothing wrong with a propane burner, I have one and it works great, but I don't like exchanging bottles, and I don't like pressure drops on the propane tank, especially in cold weather.

    A siphon nozzle burner will start at full power with no furnace preheating (running on diesel), will operate equally well in summer or cold winter, will melt aluminum extremely quickly (too fast if you are not careful), and will melt your furnace into a puddle in a few minutes if you don't have 2800 F or higher refractory in your furnace.
    I have routinely melted 20 lbs of aluminum in 12 minutes from a cold start with a siphon nozzle running on diesel (very easy to overheat aluminum if you don't pay attention).
    Attached Images Attached Images

  3. #13
    Senior Member Zapins's Avatar
    Join Date
    Jun 2010
    CT, Hamden
    The most helpful & thorough explanation of how to get a siphon burner running that I've seen. Thank you.

    Looks like I am almost there and just needed the needle valves for proper control. Will give it another try this summer.

  4. #14
    Senior Member
    Join Date
    Jan 2012
    Buffalo, NY
    I can't add much to what's been said. I hope this is made into a sticky. I've made 2differnt burners with a Delevan nozzle. Both times after final assembly they became plugged with debris from freshly trimmed and assembled fuel lines. A quick run through with an undersized torch tip cleaner may yield a culprit!


  5. #15
    Senior Member Zapins's Avatar
    Join Date
    Jun 2010
    CT, Hamden
    I agree on the sticky. I was thinking that too when reading it. Should be duplicated and split off into a sticky thread.

  6. #16
    hello, thanks a lot for all your replies today I have tried with diesel, it still didn't work only when i raised the tank well above the furnace level, it turned on for a bit. but thats it. I will have to make a pressurized vessel and follow the above as stated thanks a lot i will update when I will have made al of that

    Thanks A LOT

  7. #17
    Hey Van...ya might try this. I light my kwicky outside the furnace. I run only about 5psi of compressed air pressure on the nozzle and crack open the diesel. I point it at a propane torch and it lights. At first it's a big black smokey flame, then I slip it into the furnace with the lid open and start hitting it with the blower. I've tried lighting it with a rag in the furnace on fire. That works too, but when it ignites, it makes one heck of a BOOM
    Visit me:
    "Sometimes by losing a battle you find a new way to win the war"
    -- Donald Trump --

  8. #18
    Quote Originally Posted by cjcaster View Post
    The secrets to a reliable siphon nozzle burner:
    That's terrific stuff, right there.

    I just logged on to see about some advice for tuning my brand new burner build, but I'm not even going to ask. I'm going to work through your procedure instead.

    My initial test fires have been using random waste oil I have around. It's a mixture of every petro fluid on my motorcycle and my truck: Engine oil, ATF, gear oil, and even a small amount of DOT 5 brake fluid.

    I'm going to get some Diesel and try that.

    If nothing else, I am pleased to have at least gotten this thing to where it will stay lit! I hope to have it tuned and running properly in a week. We'll see.

    Thanks again for that great post.

    Here's a video of my second test fire: No blower applied yet, but I was pleased to at least get it to stay lit.

  9. #19
    Join Date
    Mar 2016
    Tornado alley, USA
    Generally a siphon nozzle running on oil or diesel will not operate outside the furnace.
    (Edit: Some people have been able to operate a siphon nozzle burner outside the furnace, but the point is moot; the idea is to set up the burner to operate correctly when it is attached to the furnace, so that you can melt metal).
    I have run mine outside the furnace on diesel with a separate propane torch adjacent to keep it burning, but never with the blower running.

    It is not designed to operate outside the furnace.

    Also if the siphon nozzle tip is not within an inch or less of the end of the burner tube (the end of the burner tube towards the furnace) then the burner will not work at all.

    Always be ready to immediately turn off the fuel ball valve if you have a flame out, when you are learning how to operate it.

    Good luck.
    Last edited by cjcaster; 06-02-2017 at 10:40 PM.

  10. #20
    Having studied this some more, I have a few questions:

    - I'm using a Hago brand nozzle with a .75 gph tip. Does that change anything from the instructions?

    - How large of an air compressor are you using? Any idea how many cfm you need to maintain? All I currently have is a very old, very worn pancake type. I've been looking for a reason to replace it. Is this it?

    - This may relate to my first question, but5psi for the fuel feed seems like a lot. I had figured on gravity feeding this with something like 24 to 36 inches of head, which I calculate will get me maybe a little more than 1psi over atmospheric. Am I missing or miscalculating something?

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