Unist 4210 Series, Operation Manual

13

3. Adjust the 

LIQUID

 and 

AIR

 flow control valves until the 

desired spray pattern is obtained. If necessary, adjust the 
air and fluid pressure as well. Lock the needle valves in 
place by turning the jam nut clockwise until tight.

4. Repeat for each nozzle.

Note:

 Too much atomizing air flow will cause excessive 

mist and result in an undesirable fog.

Using the Unist SPR-2000

™

 or SPR-2000 JR

™

 controller 

or the customer supplied controller, the valves will need 
to be programmed to cycle at the appropriate time for the 
necessary duration to satisfy the application. Consult the 
SPR-2000

™

 or SPR-2000 JR

™

 manual for further details.

Adjust The System For Pressure Drops

1. Depending on the system configuration, having 
multiple nozzles operating at once can cause a pressure 
drop across the valve stack in both the air and the fluid.  
To account for this, simulate the anticipated drop by 
turning on as many nozzles as you anticipate would be 
on at any one time in your operation. If the spray nozzles 
are no longer giving spray pattern set in step 3, increase 
the incoming air and fluid pressure at the controller’s 
or fluid supply regulator until they are once again 
giving the desired spray pattern.

Ensure Fluid Is Connected

1. Open the 

LIQUID

 needle valve on the nozzle body 

(4210 series)

 or the valve stack 

(4230 series)

 by turning 

the needle valve 1 full turn counter-clockwise. Actuate 
the solenoid valve and wait for the fluid to fill the 
tubing and for a steady stream to come out of the nozzle. 
Depending on fluid pressure, fluid viscosity and tubing 
length, this can take a minute or more.

a. If no fluid appears, refer to the Troubleshooting: 

Fluid not coming out of nozzle section of this manual 

(page 9).

3. Close the 

LIQUID

 needle valve.

4. Repeat for each nozzle.

Adjust The Spray Pattern

1. For each nozzle on the stack 

(4210 series)

 turn the 

AIR

 needle valve on the side of the nozzle body 1/2 turn 

counter-clockwise to open it. 

(4230 series)

 Turn 

the 

Atomize

 needle valve on the top of the solenoid 

valve attached to the nozzle 1/2 turn counter-clockwise 
to open it.

2. Place a piece of cardboard or other absorbent material 
in the spot that will be sprayed. Actuate the valve for 1-2 
seconds and check the spray pattern.

Startup & Operation

Figure 33: Opening the LIQUID needle valve (4210)

Figure 34: Opening the Liquid needle valve (4230)

Figure 35: Adjusting spray pattern

Figure 36: Adjusting spray pattern