Flow control needle valves (unidirectional flow control valves) allow fluid to freely flow in one direction. These valves consist of a heavy duty carbon steel body composition and have a micrometer adjustment knob for accurate valve setting. An Allen Head lock screw locks the handle in place. Our needle valves are rated to 5000 PSI and available in 1/4" to 1-1/4" NPT port sizes. SAE porting options available upon request.