Adjust Airflow not using Ball Valves
Yes, you can use a hydraulic needle valve to adjust the airflow if you want. These can be purchased online at Northerntool.com or Grainger.com or in your local farm store. Most have a ¼”, 3/8” or ½” female NPT threads on both sides. You can purchase a brass fitting with male threads on one side and a hose barb on the other side and connect it in-line if you want a more precise adjustment.