It gets pumped at a party

KEG

This large container often holds beer and might be tapped with a spigot for serving. You’ll usually find it chilled and surrounded by cups at gatherings.

At a party, a "keg" is a large barrel of beer that gets tapped and pumped to serve drinks. The clue plays on the double meaning of "pumped"—literally, beer is pumped from the keg, but it also hints at the lively energy of a party where people are excited ("pumped up"). The answer is straightforward once you think of what’s central to many celebrations and fits the wordplay.