Securing Stove Pipe Connections

 
Kenbod
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Post by Kenbod » Wed. Oct. 08, 2008 11:48 pm

PUFFBACK IS REAL!

And, impressive when it occurs. I have no interest in experiencing another, ever. My manual boiler was a classic set-up: big 100# firebox with manual make-up air and feed vents with pretty tight construction. When the thermostatic damper closed, there was lots of heat sequested in that 100# of hot coal. Enough heat to absolutely insure that the firebox temp would be higher than the flash points of the volatile gasses. I was careful and I opened the door s-l-o-w-l-y. Still too fast! It was explosive. And the door blew wide open. It's probably the only thing that saved my chimney pipes (which were not screwed together). The make up are slit is a much better choice.

It would have been a mess if those pipes had come apart in my basement with 100# burning and an open 8" breech.

Now, I don't know if stokers have the same risk with their much smaller burning volumes and constantly running ventilation fans, but I've had my epiphany. Consider me a convert on puff-back. Puff-Diddy is a different story.

 
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Freddy
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Post by Freddy » Thu. Oct. 09, 2008 4:57 am

Kenbod wrote:I was careful and I opened the door s-l-o-w-l-y. Still too fast!
So, for you, what is the correct way to insure you do not get a puff back?

 
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Devil505
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Post by Devil505 » Thu. Oct. 09, 2008 8:34 am

Freddy wrote:So, for you, what is the correct way to insure you do not get a puff back?
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.


 
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Devil505
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Post by Devil505 » Thu. Oct. 09, 2008 10:13 am

SMITTY wrote:Not to trump what these guys are saying........ or to suggest that you do anything I do...... :funny:

But I have no screws in any of my joints on the pipe. I use fireplace mortar to hold the pipe in the chimney. Why? Because I'm lazy & want to avoid any extra steps in shutting down my stove for the season! :roll:
Stove pipe 002.jpg
Stove pipe 003.jpg
I set the stove in place so that the pipe perfectly lined up with the hole in the chimney. Once I wrestle the pipe in there & mortar it up, that pipe wouldn't come out of there if it wanted to!

Solid. Redneck style! toothy :woot: :lol:

That chimney pulls a killer draft -- I may be lazy, but wouldn't endanger the wifey & the cats.
Do you leave your stovepipes up all summer or keep your stove running?
I always take down the stove pipe in the Spring & leave it off all Summer to avoid moisture & corrosion. If I didn't do that I would probably have to replace it all every year. Screws let you easily take it all apart.

 
Jack Magnum
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Post by Jack Magnum » Thu. Oct. 09, 2008 10:00 pm

Devil,
You take all your stove pipe apart from the stove collar to the chimney? Do you coat it with something? What about the main chimney or in my case the outside metal chimney,What should be done for Summer non use.

 
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gambler
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Post by gambler » Thu. Oct. 09, 2008 10:09 pm

Jack Magnum wrote:You take all your stove pipe apart from the stove collar to the chimney? Do you coat it with something? What about the main chimney or in my case the outside metal chimney,What should be done for Summer non use.
I am not Devil but I also remove my stove pipe from the stove to the thimble and brush it out along with my prefab chimney then I wash the inside of both with baking soda and water using a sponge setup I have for on the end of my cleaning rod.


 
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Devil505
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Post by Devil505 » Thu. Oct. 09, 2008 10:12 pm

Jack Magnum wrote:Devil,
You take all your stove pipe apart from the stove collar to the chimney? Yes I do..It's only 2 sections of stove pipe & a 90* elbow. I just take it down for the summer & seal the wall thimble. (I have left it all connected a few summers & found it rots out quickly due to summertime humidity)

Do you coat it with something? What about the main chimney or in my case the outside metal chimney,What should be done for Summer non use.
I don't coat it with anything. Just keep it in a dry place. My main chimney is masonry block so it requires nothing.

 
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SMITTY
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Post by SMITTY » Fri. Oct. 10, 2008 7:10 pm

Devil505 wrote:Do you leave your stovepipes up all summer or keep your stove running?
I always take down the stove pipe in the Spring & leave it off all Summer to avoid moisture & corrosion. If I didn't do that I would probably have to replace it all every year. Screws let you easily take it all apart.
No. I take it down too. Learned the hard way after the first pipe...........
Stovepipe 016.jpg
.JPG | 243.7KB | Stovepipe 016.jpg
That was pipe # 1. I'm on #2 which is 304 SS, & that has pinholes all over -- left that one hooked up too. Not big enough to cause any concern yet. This will be it's 3rd season.....& most likely it's last!

Now I take it down, clean it, & bring it upstairs for the summer. Took a while for that to sink in -- my brain is pickled in bourbon whiskey............ :lol:

#3 will be 316 SS, which is what I should have done in the first place! That's what I get for being a cheapskate. ;)

 
Kenbod
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Post by Kenbod » Fri. Oct. 10, 2008 8:07 pm

Responding to Freddy:

The best way for me to prevent puff-back on the big manual load boiler is to make sure that the "make up" air opening is always open enough to keep those volatiles burning. The main air supply comes from below the coals and is controlled by a thermostatic damper. The make-up air can be as much art as science. Wide open admits cooler air, cools the boiler, and reduces draft and can probably fuel some burning of the coal below. Closed allows methane accumulation and maximum draft (that's where the baro damper is a savior).

I somehow doubt similar conditions could readily exist inside a stoker.

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