DVL Stove Adapter to Stove Collar; screw or not?

[danking49]

I read on one thread here that Dura-Vent said it was not necessary to screw a DVL adapter to the stove collar; only to the DVL pipe above it. Yet today I was told by Dura-Vent that the adapter should be screwed to the collar. My certified installer did not install screws.
Has anyone figured out what the best practice is? One arguement is as long as all the connections above the stove are screwed together, there is no need to screw the adapter to the collar. I've also heard the arguement that everything should be screwed down tight. Another approach is to screw all joints EXCEPT the slip joint to allow for expansion.
My thinking at this point is that I should probably tap the collar for 10-24 screws, cut them to an axact length to get through the outer adapter pipe and just to the inside of the collar, but no deeper. I'd also add a spacer or shim beteen the outer adapter pipe and the stove collar so I can torque the screws down snug without crushing the adapter; with a star lock washer just for grins.
I may be obsessing a little about this, but I rather not find myself living in the camper should the pipe overfire and make like a roman candle in the living room someday.

Thanks for the opinions

 

[Hogwildz]

Put some furnace cement in the inside of stove collar, set adapter down into stove outlet and from inside work the furnace cement smooth and even, then screw the adapter to the collar with stainless 3 screws.
Use some never seize on the screws at final setting. Be careful, all the stainless screws I ever used were soft and break very easily. One of my screws holding the adapter on has no head on it anymore.
Hope I never have to pull the liner off.

 

[pinewoodburner]

I did not screw my DVL adapter to the stove collar. I used the Selkirk pipe. Everything else is screwed together and with the stove at 500 lbs, the stove pipe does not budge. Once I put the screws in the adjustible pipe, everything was locked together. There was no way to see where the 3 pre-drilled holes are at on the stove collar.

 

[Metal]

If it is rear exit, then screw it on (self tapping screws should do the trick). If it is top exit, then it is up to you. Do not put screws in the variable length.

 

[Highbeam]

RI: THere is no answer. I have also seeked this information and until recently had never actually seen anyone attach any of the double wall products to their stove. If you have a rear vent stove then you need to figure out a way to attach it with screws. Even if it crushes the outer wall a bit or if the screws penetrate into the actual flue as they would sith single wall. There is no problem with the screw tips running into the flue and the double pierce is superior.

If you have a top vent as mine then it is more optional. I "drilled" my installer and building inspector about this and they all said that it shouldn't be screwed to the collar. My slip joint is screwed so it is of fixed length. Those are the only screws in the connector pipe system. Theory is that the expanded slip joint can't fall out of top or bottom since it is stuck in the stove and in the ceiling adapter.

If it was easy I would do it too. Maybe the adpater is easier, did you get a damper in the adapter?

 

[danking49]

Highbeam,
Thanks, you're getting the same 'non-anwers' I'm getting. Its a Quad Millenium with the flue collar on top, and all joints except the adapter to stove connection are screwed together; including the slip joint. The adapter does not have a damper. I agree it probably isn't going anywhere; but then again I've never experienced a run away chimney fire and don't really understand excactly what forces would be at work in such a case.

I'm still playing email tag with Duravent. To essentially the same question as I started this thread with, the last email said:

"The screw would go through the inner sleeve of the adapter directly into the stove collar."

Now, because the inner sleeve of a DVL stove adapter goes inside the stove collar, the only way to do this (magic aside) is to screw the inner sleeve to the stove collar from INSIDE the sleeve. This, of course, involves some fairly comlex precise measurents to get the holes drilled in the right places along with an offset screwdriver etc... It that's the real solution, it's no wonder few, if any, installers screw that adapter to the stove.

I see a marketing opportunity here for a creative mind with access to a small machine/sheetmedal shop!