Plumbing--need your help

[Delphinus]

I think technically you need an elbow for it to be considered a "Durso" but ignoring that technicality I think this would work just fine (with or without the elbows on the inside). In fact you could put strainers on the bulkheads if you went without the elbows. (I wish I could put a strainer on my FW overflow because small fish end up in my sump all the time (dang Ameca splendens breed worse than rabbits - I think they are born pregnant).)