Question about stovepipe screws and thermal expansion

[7acres]

My DuraPlus double wall stovepipe length from flue exit to chimney support box is 6' 2". I've got it all screwed down. 3 Screws secured at the flue. 3 Screws secured in the middle. 3 Screws secured at the support box. The pipe is perfectly vertically level.

I know there's some differing opinions on whether to leave the middle screws in or not to allow for thermal expansion. With a ~6' stovepipe should I leave the middle screws in or take them out so the pipe can telescope in and out as the metal heats and cools?

 

[begreen]

DuraVent DVL double-wall connector instructions say to screw in the middle too.

https://www.hearth.com/talk/threads/securing-telescoping-double-wall-stove-pipe.80222/

 

[bholler]

I usually leave them out but lots say to put them in i doubt it will be a problem either way. I have seen screw holes get wallowed out on single wall in this configuration but not on double wall

 

[bholler]

If the instructions say to do it then do it

 

[7acres]

Thanks! I'll leave them in.