triple walled pipe

I recently aquired 16 ft of used triple walled pipe (I think it's galvanized). The outer middle and inner sleeves on the pipe were seperate (just slid together). I had to completely dismantle the pipe to get it out of the house. I was wondering how I know if this is still useable? How much of this stuff do I need for a Rocket mass heater? Is it safe? Does it still meet code for going through a structure?

Josh Kronberg : It Should be Fine, I would not feel comfortable determining safety for someone else even with pictures, I would just go look at some new stuff and
compare the two ! There is no good reason to include the triple wall in your Rocket Mass Heater over simpler cheaper and replaceable Heat risers made out of stove
pipe, Perlite, ( NOT horticultural grade PLEASE ! ) and Clay Slip. Your R.M.H. would be a good place to put questionable pieces, get a second opinion if you can't
tell ! I have seen triple wall Ts stood up and turned into Rocket Stoves for demonstration purposes with the fire being fed continuously for hours, with zero damage,
as long as your pipe was installed correctly and you didn't ake an ax to it to get it apart You should be fine !

Your best return on investment may be in showing to your neighbors how carefully and safely you are installing your R.M.H. Hope you scored all the brackets and
hangers !
For the good of the craft