Air Valve Truck

air valve
A valve controlling the passage of air. Also a valve admitting air to a steam boiler, preventing the formation of a partial vacuum when the steam condenses.
A valve mounted on top of a tank car through which air pressure (or other gas pressure) is introduced to facilitate unloading.
Control valve in an air system for setting volume and pressure.

truck
Barter or exchange
an automotive vehicle suitable for hauling
convey (goods etc.) by truck; "truck fresh vegetables across the mountains"
hand truck: a handcart that has a frame with two low wheels and a ledge at the bottom and handles at the top; used to move crates or other heavy objects