air suction valve

turbine blade suction side

suction

suction face of a propeller blade

suction face of an aerofoil section

boundary layer suction

flap suction

inserted suction flap

suction flap

check valve / non-return valve

non-return valve / check valve

air valve bank

air breed valve

air input valve

air slide valve

auxiliary air valve

aerial refueling / air refueling / in-flight refueling (IFR) / air-to-air refueling (AAR)

air combat capable helicopter / air-to-air capable helicopter

air support field pack, field pack air support, airborne / para (air support) / Pathfinder Bergen

amplifying valve

directional-control hydraulic valve

fuel needle valve

inlet valve

vent valve

valve rocker shank

fuel tank selector valve

fuel-return valve (FRV)

oil cooler bypass valve

slave valve

valve chatter

adjustable valve

automatic inlet valve

ball check valve