A valve assembly includes a connector including a receiving space longitudinally defined therein and a shoulder formed on a periphery of the receiving space. The connector has a first through hole laterally defined therein. A hollow block has an annular flange radially extending from a middle portion thereof to divide the hollow block into an insertion and a connecting portion. The insertion is received in the receiving space in the connector. A sleeve has a connecting portion sleeved on the connecting portion of the hollow block and engaged to the annular flange. The sleeve is formed with a protrusion and has a skirt radially extending therefrom for being engaged to the connector. A resilient member is sleeved on the connecting portion of the sleeve. The resilient member has a first end abutting the skirt and a second end abutting the shoulder of the connector.