LV Nozzle not shutting off.

Initial Troubleshooting Information:

• General Operation: The LV nozzle is an air-pilot valve. This means that there is a valve internal to the LV nozzle body and that an air signal causes that valve to open. If the air signal is not there or not strong enough, the valve will not open and fluid will not flow.
• Needle Valves: The needle valves on the nozzle body (4210 series) or on the valve body (4230 series) are meant to just meter the air and liquid flow. They will not provide full shutoff and should not be tightened past finger tight. Excessive tightening can cause damage to the needle valve.
• Air Pressure: The minimum air pressure required at the valve is 40 PSI. This may need to increase up to 60 PSI depending on how many valves are on the system and how much atomize air is being used.
• Fluid Pressure: Fluid pressure requirements will vary based off the fluid viscosity, tubing length and the amount of nozzles running off the fluid supply. In general a water based fluid or light oil will only require about 20 PSI of fluid pressure, where as a thicker oil may require up to 100 PSI of fluid pressure.
• Fluid Properties: If the fluid being used is known to coagulate, leave a film or have other disruptive properties, it is recommended to flush the nozzle with an appropriate cleaning agent. This will prevent the nozzle from becoming clogged or o-rings from leaking.
• Response Time: The on/off response time of a nozzle is mostly dependent on the tubing length between the valve and the nozzle. The longer the tubing length, the longer the response time.

Follow the flow chart to systematically troubleshoot your LV nozzle: