Yes, my system is very much like yours and I also have the trash guard on the end into the pond.
beginning on pond side there is a 12" tee, short 12" pipe, 22 degree ell down into pond, 12" pipe, then 22 degree ell up, 12" pipe and finally the trash guard on end which is about 12 to 14 foot down into pond. pond depth is approximately 18 foot deep at dam area.
materials came from Macon Georgia, pondampiping.com
by the way, my vent comes off the top of the 12" tee (same as yours will ) and remains 4" all the way, have it set to be 1" above normal pond level.
my experience (thanks to the forum members for all the advice and suggestions) so far says make sure you get all joints properly primed and glued per the directions on the cans. that is what contributed to my original failure....12" schedule 40 pvc hard to work with and mucho heavy...yours should not be quite so bad.
JET
