I would like to adapt a BBQ Viper fan to the Bronco drum smoker. You can't do it at the top because of the screw there. I was thinking that I would remove the top half of the intake pipe which would leave the bottom section which is a perfect round. Not knowing anything about plumbing parts, is there an adapter that would reduce the 2" diameter intake pipe to a diameter that fits the viper? BBQ Guru does not make one but, I know that PVC pipes can be reduced to just about any size so, there must be a metal equivalent. Or, would it be safe to use PVC? I can grab the intake tube with my hand and it is only warm.