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Gas safety valve questions
oldgrumpus
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Posted on 07/14/2021 11:47 PM
This thread is about the gas safety valve I've installed on my drum roaster. It is NOT about the flame-modulating valve.

I've built and completed my drum roaster and roasted about 40+ times over the course of the last 14 months. Twice, my gas safety valve shut off during the roast because the pilot light went out. After the first incident, I replaced the thermocouple thinking it was probably faulty, but it happened again after about 8 months of working perfectly.

I've searched the forums for examples of others who have installed safety valves but haven't been able to find any. I'd appreciate input from folks with knowledge or experience. Have you used a safety valve on your roaster? What brand? What model? Does it use a pilot flame or a spark igniter? Do I even need a safety valve?

My burner has about 30,000 btu so the valve needed is relatively small compared to one used on a home furnace. Also, I am using propane if that makes any difference... and yes, the appropriate propane kit was installed in the valve...

Thanks!!
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
Build thread https://homeroast...post_38189
 
JETROASTER
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Posted on 07/19/2021 3:07 PM
Did the pilot light actually go out?....and why?
If the pilot light actually flamed out...the safety valve is doing it's job.

If propane delivery is being randomly impeded, I'd being thinking about tank freeze. (this is normally only an issue on 20lb tank or smaller)
Cheers, Scott
 
oldgrumpus
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Posted on 07/22/2021 5:35 PM
Thanks for the reply... To answer:

Yes, it flamed-out and yes, the valve is doing its job. That much is known. What I don't know is why?

It definitely is NOT that the propane delivery is impeded. The tank is near full and the gas flow is a trickle so the tank is barely cooling itself as the gas is consumed. No freezing or moderate cooling. We are talking about a 30,000 btu burner @ 50% or less (15,000 btu). It's comparable to a table-top barbeque.

So where's the problem? I befuddled. It's not wind blowing the pilot flame out. But I'm wondering if there is some fault in the design of the pilot light flame ANGLE or PLACEMENT??
oldgrumpus attached the following image:
burner_4.jpg
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
Build thread https://homeroast...post_38189
 
JETROASTER
Top  #4 Print Post
Posted on 07/23/2021 10:42 AM
Hello,
Placement looks good. Tip is glowing. I'd be suspecting the valve itself, if you've eliminated everything else.
A couple no cost options to be thorough;
Double check the thermocouple seat...make sure everything is A+ after the earlier replacement.
Switch tanks just for fun....I've had some crappy ones.
Good Luck, Cheers, Scott
 
oldgrumpus
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Posted on 07/23/2021 7:17 PM
I switched tanks and regulators as you suggested and it made no difference.

Then the "light bulb" went on. I never did swap out the default natural gas pilot orifice (which has much smaller holes)! That's why the pilot flame was weak. The photo was not recent... but from a test I had done using a regulator with a higher output. Oy! This belongs in the thread, "The Island of Misfit Toys"!
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
Build thread https://homeroast...post_38189
 
JETROASTER
Top  #6 Print Post
Posted on 07/24/2021 9:46 AM
Good catch! >makes mental note< I'll be converting to NG soon.....I would've overlooked the pilot as well.

Not quite "misfit toy" level stuff. If you had thrown out tons of stuff BEFORE figuring it out...then maybe.
Here's the link all the same
https://homeroast...post_35555
Cheers!
 
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