Needle valves have a slender, tapered point at the end of the valve stem that is lowered through the seat to restrict or block flow. Fluid flowing through the valve turns 90 degrees and passes through ...

Description: Hayward NVA Series needle valves are used for accurate metering of fluids. Turning the thumbwheel moves a tapered piston into the PTFE seat to control the flow down to a few drops per ...