Graco 3A2098H Dispense from Each Valve, Verify Flow Meter Calibration

Operation

Dispense from Each Valve

Dispense from each valve that will be used in normal operation to confirm that the entire system is installed correctly and is capable of delivering desired results.

Follow the steps outlined in Dispense From Mainte- nance Screen, page 43, to perform each of the follow- ing applicable system verification checks.

NOTE: Each fluid plate controls only the dispense valves connected to it.

• For each valve that will be used during normal oper-

ation, dispense at each pressure or flow rate that

will be used during normal operation. This verifica-

tion check confirms that the system is capable of

delivering material at your maximum desired operat-

ing point.

• For systems that will operate multiple valves in pres-

sure mode at the same time, dispense from each

valve at the same time. This verification check con-

firms that the system is capable of delivering mate-

rial at your maximum desired operating point.

• For each valve operating in bead mode, perform an

initial teaching process. Follow this procedure after

significant system and/or material characteristic

changes.

a. For each flow rate that will be used during nor-

Verify Flow Meter Calibration

Most sealant and adhesive materials are compressible. Since the flow meter measures the material under high pressure, the actual volume of material dispensed may vary slightly from the measured volume, due to this compressibility. If the K-factor is not correct, the dis- played volume will not be accurate.

Follow either of the following methods to calibrate the flow meter during initial setup and on a routine basis to check for flow meter wear.

Method 1. Using a gram scale

1.Record the flow meter k-factor shown on Fluid Plate x, screen 4 (Flowmeter Settings). See FIG. 23 on page 35.

2.Use a 500 cc or larger beaker. Measure the mass of the empty beaker.

3.Manually dispense material into the beaker. Hold the beaker so that the stream of material is sub- merged in the captured material to minimize air entrapment in the container.

4.Record the volume dispensed on Fluid Plate x, screen 1. See FIG. 30 on page 43.

5.Calculate the actual volume dispensed:

fluid mass (g)

mal operation, press	until PCF achieves
the flow rate setpoint.

density (g/cc)

= measure volume (cc)

6. Calculate the new flow meter K-factor:

NOTE: During the initial system operation verification, it may take four to five seconds for the system to learn system characteristics.

K-Factor (new) =

displayed volume (cc) x K-Factor (old)

b.Continue to press for several seconds after the desire flow rate is reached to confirm

that the system is capable of maintaining the desired flow rate.

c.Repeat Steps a and b for a range of flow rates to confirm that the system responds quickly to

achieve setpoint when is pressed.

measured volume (cc)

7.Enter new K-factor.

8.Repeat the procedure to verify the new K-factor.

Method 2. Without using a gram scale, visual measure- ment

1.Record the flow meter k-factor shown on Fluid Plate x, screen 4 (Flowmeter Settings). See FIG. 23 on page 35.

2.Use a 500 cc or larger beaker.

42 3A2098H