Final answer:
To properly position a coupler on a standard American keg, align it with the keg valve, insert and turn it clockwise, then push the coupler handle down to seal and allow beer flow.
Step-by-step explanation:
The proper positioning of a coupler when engaged on a standard American keg involves several steps to ensure a secure and proper connection for dispensing beer. Initially, the coupler should be aligned with the keg valve in an upright position.
It is important that the coupler handle is in the open position (pulled out) before inserting the coupler into the keg valve. Once properly aligned, the coupler is pushed down into the keg valve and then turned about a quarter turn clockwise to engage and lock it in place.
After this, the coupler handle is pushed down into the closed position to create a seal and allow for the flow of beer and pressurized gas. The coupler should fit snugly to prevent any leakage of beer or gas. To ensure success, double-checking the attachment and verifying the absence of leaks is necessary.