Air Control Needle Valves Controls air volume supplied to pump, thus permitting operator to control speed of pump. Lock-Out Valves Meets OSHA lock-out/ tag-out regulations Solenoid Valves Uses an electronic signal to control the fluid or air supply Measuring Cylinders Dispenses predetermined quantities of fluid or semi-fluid material Manual Control Valve Four-way control valve for ARO measuring cylinders Over-Run Controls / ARO-STOP Valve Shuts off air to the pump when material container is empty or when the line is broken