Courtesy of Jetdoc, here are some more drawings.

These are not specifically for the B777, but from other Boeing types, but they are probably very similar to the 777 variants.

Click the thumbnails for bigger images.

1/ A Typical auto-sumping installation, or water scavenge system.




2/ A typical Boeing vent system




3/ A typical boost pump and override/jettison pump installation




Thanks again for making these available, also to Jet II and all the others who post diagrams, images and other information!

Bernd