Drain plumbing help needed

[Algaeking]

I am in the process of building a 240g with a 20" external overflow. The overflow will have two 1.5 inch drains that will "Y" to a single 2" pipe that will drain out to the garage (through the wall) where the sump will be.

I need some suggestions on what style drain I should use?

I was thinking Herbie and "Y'ing" the two pipes together after the gate valve I appreciate your suggestions

 

[Algaeking]

Bump

 

[dumnorix]

With that kind of room to maneuver, I would personally go with a pair of Durso standpipes - they take approximately 3 minutes to make after you have the parts - and I would make them out of 2" material - then down to 1.5" below the bulkhead. Then I would definitely go for a 1.5" to 3" wye so you know you are doing your best to handle the amount of flow coming through - especially if you have the ability to scale back if needed with the gate valves on the 1.5"
Just my 2 cents, but why bottleneck the 2 1.5" drains into 2"???

 

[Mr James]

Many moons ago I helped plumb a 240g reef tank. The twin 1.5" drains (if I remember correctly) went into a 4" manifold and then on to the sump. I guess I don't understand your term "y'ing"... Can you explain or show a diagram?