I got 2 of the 6" plastic blast gates from clearvue. I am using pvc dwv 6" fittings for much of the ducting. The blast gate doesn't fit into the pvc coupler, and it is slightly bigger than the 6" pvc pipe. The 6" flex hose is way smaller than the 6" blast gate. I haven't yet been able to find a fitting converting the pvc to the uncommon size of the 6" blast gate, or allowing 6" flex hose hookup to the blast gate. Any suggestions?