This is a full port ball valve with a 14mm bore which allows maximum flow rate through the ball valve. 

The valve comes with Teflon tape already on the nipple, a silicon o-ring which is seated in the ½” BSP nut. The seat in the nut prevents the o-ring from rolling out of place when tightening.

Add a 1/2 BSP hose barb on the outlet, allowing you to fit heat proof silicone hose (11-14mm inside diameter hose. 
On the inside of the vessel the ½” BSP nipple usually protrudes approximately 16mm meaning you can attach an elbow to the inside of the vessel so it draws from the bottom (shown in the picture to the left)

Installation: This ball valve is sold as a complete assembly so all you have to do is drill your 20mm hole in your keg, pot or vessel wall and you can fit this ball valve.