How does duravent DVL expandabile pipe work?...working with 6" pipe

[JPapiPE]

I can't imagine how an insulated double wall pipe can telescope to different lengths without causing a need to increase fittings to the ht chimney and/or to the stove itself. I'm guessing that a 6" dvl duravent double wall stove pipe must measure about 7" on the outside diameter, but then you add the telescoping factor into the pipe and what does that do the ends of the pipe? What size of adaptors does one need.? Certainty expansion adaptors at leaset at one end of the pipe. Users and experts please tell the story of this pipe.
Most greatfully yours ,Joe

 

[Eric Johnson]

I don't really know anything about it except that I have a Duratech chimney that connects to my boiler with a piece of black stove pipe that slides up into the chimney connector so that you don't have to cut the pipe for a good fit. Is that what you're talking about?

 

[Highbeam]

It isn't "insulated" with anything but air. It is a double wall pipe with an air gap and yes, the OD of the assembly is more than 6", close to 8". The top and bottom of that piece is designed to allow conenction to other pipes or fittings as though it were a fixed length of double wall. It works great as a single piece between the ceiling and your appliance!

 

[JPapiPE]

Thanks eric and highbeam...I think you have at least answered half my question...Goof stuff, eh?
Thanks joe