Puff Backs

On another thread, this topic is being discussed & since we are all "lighting up" (or close to it) I figured it deserved it's own thread again.
I don't think stokers are prone to these but Hand Fired stoves & probably furnaces/boilers are.
I'm not an engineer but from a layman's standpoint a "Puff Back" is the sudden ignition of volatile gases given off by adding fresh coal to your fire. These Puff Backs can be quite violent & is the reason why it is recommended that you secure your stove pipe with 3 screws per joint to avoid blowing them apart with a bad Puff Back.

This is how I avoid them:

In a hand fired, I recommend leaving a small section uncovered & still flaming (to burn off volatiles) whenever you load/reload your stove. (cover the whole bed with coal only when there are flames showing somewhere in the stove)
We had this discussion last year & I guess some people never have puff backs due to their stove/chimney configuration. I've had 3 stoves & puff backs in all 3 if I don't burn off the volatiles on loading.
I don't think it is even possible for a stove to puff-back if you are burning off the gases......No gases are being allowed to accumulate.

I never had this problem until this year.Most of the time I burnned mystery coal,but at the end of last year I got some superior coal.YEEEE....HAAAA when that stuff lights up it has some gusto! It seems that deep mined fresh coal has more volitiles in it.But on the other hand it lights very EZ.
DON