what is keg coupler
Keg Couplers for Tapping Any Type of Keg. A keg coupler is what connects the keg to the air line and beer line. Itâs what physically âtapsâ the keg valve, causing gas to flow in and beer to flow out. Couplers can differ from keg to keg depending on the type and brand of beer being purchased.eg Couplers for Tapping Any Type of Keg. A keg coupler is what connects the keg to the air line and beer line. Itâs what physically âtapsâ the keg valve, causing gas to flow in and beer to flow out. Couplers can differ from keg to keg depending on the type and brand of beer being purchased.