That is a durso setup.
I would advise against using a ball or gate valve on this setup. Less chance of obstructing the pipe and flow of water.
Getting a straight drop from the durso pipe to the sump is ideal, but as few bends as possible is advised. I myself prefer to use 45 elbows instead of 90's, this way there is less chance of an air pocket building up in the pipe.
You could even use flex tubing if you wanted to.
Some people complain of excessive nose from this design, but usually it happens when an oversized pump is used. The ones durso pipes that come with marineland/perfecto/aqueon tanks are rated for about 700gph.