I'm installing (with help from a contractor) a new vermont castings Encore wood stove. The chimney (Duravent DVL) has been installed and actually used temporarily with another stove while building. We went to install the new DVL from the stove to the chimney box (not sure what you call it) I have all the piping brand new it came with the stove. However, the adaptor piece that attaches to the stove fit's very loosly. It seems to be the wrong diameter. I think it's a Duravent 6DVL-AD. I looked online and it's bottom diameter is only 5.625 inches wide. Is this supposed to be tapered so it will fit tight? Unfortunately I'm not where the stove is so it's possible for me to double check. Maybe it was just a short piece of DVL pipe I'm not sure. I thought this would be easy so I didn't bother to bring the parts back from the cabin to my house which is over 200 miles away. Thanks in advance for any help