Blichmann Hellfire with 40 pound propane tank

I am experiencing flare ups after lighting the Hellfire connected to a full 40 pound propane tank. Flame starts out nice and controlled but after a minute the burner seems to pull more propane than it can handle. Flames flare up from underneath the kettle and up the sides.  Bright, yellow flame until returning back to a somewhat typical blue flame before another pulse sends yellow flames up the kettle again. I turn off the gas but the kettle stays lit with tiny blue flames for a minute or two.  After flame dies I try lighting again.  Same thing happens.

This makes me very nervous.  I switch to a 20 pound tank.  No issues. What’s going on here?

Thanks.

I had similar issues with my SP-10s, and my 40 lb tank. My conclusion was that the youngster at the fill station had overfilled it. After some use it was back to normal.

Run it outside for a while and see if it returns to normal operation.

It sounds to me like the regulator is allowing liquid propane to pass into the burner.  My suggestion is to remove the kettle, light the burner and watch it carefully.  If my suspension is correct, and as hopfenundmalz suggested, the issue will settle down within 30 minutes or so.  If it doesn’t, I suggest returning the tank.  If the problem happens again, replace the regulator.

If your tank is able to be overfilled, then I would seriously consider replacement. The Overfill Protection Device — a float in the tank that automatically prevents filling once the gas is at 80 percent capacity, leaving enough room for the liquid to expand — is not operating correctly.

Agreed.  I believe that all new propane tanks are now required by law to have over-fill protection devices in them to prevent this issue from happening.  The local supplier that fills my tanks said that if it was an old tank without this protection device, they would not fill them as far to prevent the flare-up issue from happening.  With the newer tanks they fill them as far as the over-fill device will let them.  They also won’t fill the tanks if they are out of certification which if I remember correctly is 10 years from date of manufacture and less time (I think 5 years) after the tanks have been re-certified.

Very good points goose and BrewBama!  I agree that a replacement is probably necessary as it is most likely an older tank.  Refilling accuracy, however, is, in many cases, left to the person doing the filling and the past practice was to use a scale and fill until the proper weight is achieved.  So over filling, and under filling, is commonplace with many tanks and while the date code on the tank determines its life span, many persons doing the filling aren’t properly trained and don’t even look at the date code.  So, “good call” on the internal float valve regulation.  I was not aware of this device!