Adjustable Adhesive Pressure Relief Valve - ITW Dynatec DYNAMELT D15 Series Technical Documentation Manual

ITW Dynatec
D SERIES V6 DCL ASU Manuals

Adjustable Adhesive Pressure Relief Valve

D Series ASUs are outfitted with a high-pressure relief valve located on the outlet filter manifold.
The valve is adjustable and it does not affect adhesive pressure under normal operating conditions.
The adjustable pressure relief valve is factory set at 27 bar (400 psi).
When adhesive pressure exceeds the set limit, the pressure forces the valve to move away from its
seat, compressing the spring and allowing adhesive to flow back to the hopper. This adhesive flow
reduces pressure. When the pressure falls below the set limit, the spring forces the valve against its
seat, cutting off adhesive flow.
Normally Closed (Unrelieved):
In the drawing below, the valve is closed.
from
pump
Adhesive flow through
filter block to hose
To Adjust Pressure Relief:
Note: This adjustment should be done with a melt pressure gauge or a pressure transducer in-
stalled. Failure to use proper equipment can result in excessive pressure levels.
1. Turn the application system ON and raise the temperatures of all components to normal
operating temperatures.
2. At the controller, set the motor speed to "0" so that the gearmotor is not turning.
3. Locate the pressure relief assembly on the manifold (where the hoses attach).
4. At the controller, turn the motor ON to desired operating speed.
5. Hold the valve's mounting nut with a 7/8" wrench to prevent it from rotating during procedure.
6. Locate the valve's adjustment screw and loosen its lock nut with a 3/4" wrench.
7. Actuate (open) the valves on the applicator(s) in order to fill them with adhesive and purge air
from the system.
8. Close the valves (those opened in the last step) to stop the flow of adhesive.
9. Using a 7/16" wrench, turn the adjustment screw clockwise to increase the pressure to the
applicator(s) (or counter-clockwise to decrease pressure) until desired pressure is achieved.
CAUTION: DO NOT adjust the adjustment screw fully clockwise (closed).
Maximum operating pressure should not exceed 1000 PSI.
10. After desired pressure is achieved, tighten the lock nut. The system is now adjusted.
Open (Relieved):
In this drawing, pressure has exceeded the setting
of the valve, causing the valve to open and dis-
charge adhesive to the hopper.
Adjustment screw
Mounting nut
to
hose
Lock nut
return to
hopper
from
pump
Adhesive flow through
filter block to hose
Troubleshooting Page 7-29
Revised 10/14
to
hose