Summarize this article:

Take 2 plastic connectors with a  3⁄4 inch (1.9 cm) diameter and align the threaded side with the opening of the ball valve. Attach a connector to each side of the ball valve by turning them clockwise until they’re tight. You won’t be able to screw the connector all the way in, so make sure it’s tight and securely connected. Take another hose clamp and fit it onto the other end of the tubing so it will be in place to clamp over the connector. Leave it on the tubing so you can move it into place when you attach the valve. Let the hose clamp hang loosely on the tubing so you can move it into position after you attach the funnel to the valve. Slide the end of the funnel tube onto the ball valve by forcing it onto the connector. The tube should fit snugly but it won’t be fully secure. Don’t screw the connector so tight into the ball valve that it’s difficult to remove for cleaning. Slide the hose clamp down the tube so it’s on tip of the connector. Then, take a flathead screwdriver and tighten the screw on the hose clamp until the tube is tight and secure over the connector. Give the ball valve a good tug to make sure it’s attached securely. Take a smaller length of 1 inch (2.5 cm) diameter tubing and slide it over the open connector on the ball valve. This will serve as a mouthpiece whenever you use the beer bong. Don’t clamp the mouthpiece tubing so you can easily remove it to clean it. Fit a Y valve over the bottom of the funnel and connect 2 tubes to it to form a 2 person beer bong. You can also connect a Y valve to those tubes and connect 4 total tubes to the funnel to form a multi-person beer bong!  Use Y valves that will fit 1 inch (2.5 cm) diameter tubes. Connect ball valves to the ends of each tube so you can control the flow of liquid. You can find Y valves at hardware stores, home improvement stores, and online.

Summary:
Screw plastic hose-to-threaded connectors into the ball valve. Slide a hose clamp onto the tube at the opposite end of the funnel. Insert the funnel tubing onto the connector on the ball valve. Tighten the hose clamp over the connector with a screwdriver. Attach a 4 in (10 cm) long tube to the other connector. Use Y valves to connect more tubes to make a multi-person beer bong.