Abstract: A device for providing a disposable liner or bag and valve inside of a keg. An example device includes a valve assembly connected to a spear assembly. The disposable liner or bag is wrapped around the spear assembly to fit through a top opening in the keg and the valve assembly is connected to the top opening of the keg. A series of valves and passages enable an inert gas to flow into and expand or inflate the disposable liner or bag inside of the keg, and the valve then enables filling the disposable liner or bag inside of the keg with beer or other liquid to be dispensed from the keg. When the keg is empty, the spear assembly may be disconnected and withdrawn, thus removing both the disposable liner or bag and disposable valve assembly from the keg.