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Pilot safety

will smith_4
will smith_4 Member Posts: 259
Happy Saturday to all-

I've come across an 80+ year old Kewanee steam boiler that has seen the full gamut of fuel conversions from coal to oil to gas (as have we all, I'm sure). My problem isn't with the boiler/system (original Webster system), but rather with the gas side. When converted to a power gas burner, a Honeywell R4795 flame safeguard was implemented. The pilot burner connected to the safeguard (which I'll call the secondary) is on the right side of the burner assembly. On the left side, there is a main pilot which stays lit (on most days) all the time, and which did not have any safety to shut it down in the event that pilot flame was lost. If the flame went out, raw gas was free to flow into the burner section. On a good day, when the main pilot is lit, when there is a call for heat, another pilot solenoid energizes through the flame safeguard, and if pilot is proven through rectification on the right side f the burner the main lights.

Along comes myself. I can't sleep right at night knowing I've got an uncontrolled gas supply to the pilot. I've tried adding a Baso switch and a Husky Tcouple, the problem is, when the combustion blower kicks in, the pilot flame dances around enough to cause me to lose solid signal at the t-couple, and the Baso drops out. I've tried repositioning the t-couple, but so far, no good. Any ideas? I've used Baso switches on atmospherics forever, but with this power burner, my thought is I can't use it.

No good deed goes unpunished.

Happy Halloween-

Bill

Comments

  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    How many years

    has it worked this way? There are many applications from the past with what are called "wild pilots" or constant pilot that if they go out have no safety and are allowed to dissipate the escaping gas (natural gas is lighter than air and rises) up the vent system. If it was working fine before put it back the way it was and leave it. What is the orifice size on that pilot? The reason I am asking is I will give you how much gas is escaping if it goes out per hour. This type application could never be used however on LP as it is heavier than air.
  • will smith_4
    will smith_4 Member Posts: 259
    Worried about safety...or lack thereof

    Hi Tim-

    Thanks for getting back to me. To answer your question, the system has been like this presumably since the day it was converted over to a gas power burner-which may well have been 30-40 years ago. The mechanical room is in a negative-combustion air has been choked down, and there are no weights on the barometric damper. I'm going to get back in there to do a proper draft check, and measure up existing combustion air openings compared to required size.

    I know it would take one HECK of a downdraft to snuff the monster pilot this system has (that downdraft might actually knock the  chimney down), but my thought is :what if the gas supplier shuts down the supply for service at the street, then turns it back on? A 3/8ths line with 4.5" wc just seems a little much without a safety shut off.

    Come to think of it-since my paranoia stems from a worry that the gas could be shut off at the street with no one to relight the pilot, what do you you think of adding a manual reset low gas pressure safety switch? My main concern is for the folks that sleep in that building-maybe I'm just getting too cautious...then again, can you ever be too cautious with someone else's safety?

    Thanks for your help Tim-

    Bill
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    In the first place

    the gas supplier would never shut off gas and then just turn it back on and walk away. In fact they are required to alert customers that work is going to be done. They then shut off all the meters before doing the work, they then will turn back on all the individual meters and test everything for safety.



    I applaud your cautious approach but would advise you to leave it the way it was and resolve the air for combustion issues and negative pressure problem.
  • will smith_4
    will smith_4 Member Posts: 259
    Safety dilemma

    Hi Tim-

    I ended up putting in a manual reset low gas pressure safety in the main  pilot line, so that if the gas provider shut the supply off at the street and we lost pilot, the main burner circuit would be broken until the safety is reset and main pilot is re-lit.  The system had been doing just fine for 80+ years (until I came along, of course), and it wasn't as if I was trying to sell them an improvement in order to make a payment on my summer home in Maine (I haven't even bought that yet)-I just saw something I knew wasn't quite right , and tried to improve it.

    End of the day, my customer was happy-even though my original objective didn't work with the Baso switch. They still have a level of protection now that they didn't have before, and that's good enough for me.

    Thanks again for your help-

    Bill
  • will smith_4
    will smith_4 Member Posts: 259
    Oh by the way

    The gas suppliers around here are notorious for doing work without telling anyone what they are doing...
  • Tim McElwain
    Tim McElwain Member Posts: 4,612
    That is a

    violation of code!
This discussion has been closed.