Distance between flue and cleanout

[steviep]

Sence we are installing a new stainless ridged liner we have decided to put a new clean out in the house. The old one is outside below grade level the new one will be easier to use. My question is how far apart should they be. the easiest thing would be to use the old flue for the clean out and put a new hole in for the flue.
Secoand question is how do you insulate a ridged liner all the instructions I have found on line deal with insulating the flexable stuff.

 

[EatenByLimestone]

Why would you need a cleanout door? If the liner ended in a fireplace any creosote would empty into the fireplace or insert. If it ended in a T it would fall into the bottom of the T where it could easily be cleaned out.

Matt