Napolean Arlington - MOVE OVER

[Clemkonan]

I have a Napolean Arlington in my basement and I am doing over the floor after a small flood. The new floor will be lower than original. I have a plug ready to seal off the connection to the stove and the gas supply to the stove is turned off. My problem is that at the stove pipe it's a pipe within a pipe and I do not want to damage anything albeit the inner pipe looks flexible. I was hoping to disconnect the stove pipe plug off the line, gain access to the floor and continue the floor installion then reconnect any advice?

 

[DAKSY]

Most vertical installations of DV pipe have an adjustable - or slip - section in them.
all sections of the pipe SHOULD just twist apart, except for the slip.
That should pull apart, unless there are 3 screws holding the 2 pieces of the slip.
Re-installation will be twisting in the opposite direction & installing 3 screws at a different location.
The inner piece of the DV pipe is NOT flexible.