A pneumatic installation, especially an air suspension installation for a vehicle, operates in conjunction with a compressed air supply installation and comprises: a gallery line, at least one air spring having a pressure chamber, which can be pneumatically connected to the gallery line, an accumulator for compressed air, which is pneumatically connectable to the gallery line, and a compressed air port for pneumatic connection of the pneumatic installation and the compressed air supply installation. The pneumatic connection comprises a controllable shut-off valve system, which is formed by at least one directional valve and has first, second and third ports, the accumulator being pneumatically connected to the first port, the compressed air port being pneumatically connected to the second port, and the gallery line being pneumatically connected to the third port, the second port being switchable to a closed state in which the pneumatic connection is completely closed in both directions.