Troubleshooting Guide
No fluid flow
•
If valve operating air pressure is too low,
the valve will not open. Increase air
pressure to 70 psi (4.8 bar) minimum.
•
The reservoir air pressure may not be
high enough. Increase pressure.
•
The dispensing tip may be clogged.
Replace tip.
•
The stroke adjustment may be closed.
Open stroke adjustment.
•
Fluid may have solidified in the valve.
Clean the fluid body.
Fluid drools after the valve closes,
eventually stopping
•
This is caused when air is trapped in
the outlet section of the fluid chamber
or the fluid has entrapped air. The air
will expand after the valve closes, caus-
ing extrusion until the air reaches
atmospheric pressure.
Purge the valve by dispensing at a steady
flow until clear. If a small tip is used, it
may be necessary to remove the tip while
purging to obtain sufficient flow to carry
the air down through the tip adapter.
•
If the fluid has entrapped air, the material
must be degassed before dispensing.
Fluid drips at a steady rate after the
valve closes
•
A steady drip can be caused by exces-
sive reservoir pressure. Check to be
sure the reservoir pressure is not above
70 psi (4.8 bar).
•
If the stroke adjustment knob is turned-
out more than two full turns, resulting in
reservoir pressure that will force the
diaphragm open. Check the stroke
adjustment knob to be sure it is less
than two turns out.
•
A steady drip also indicates failure of
the diaphragm to close fully due to par-
ticle build-up or wear. In either case,
replace the sealing head in accordance
with the maintenance instructions.
Fluid leaks out between fluid body and
diaphragm
•
Fluid leakage between the fluid body and
diaphragm indicates the annular seal-
ing ridge on the fluid body is damaged or
the fluid body is distorted due to exces-
sive torque on the retaining screws. In
either case, replace the fluid body.
Fluid flows out of the drain hole
•
Fluid flowing out of the drain hole indicates
a ruptured diaphragm. Replace in accor-
dance with the maintenance instructions.
Valve responds slowly when opening
and closing
•
Valve response is related to control air
hose length and size. The valve is sup-
plied with 5-feet of 3/32” ID tubing
attached. Any additional length or size
change will affect response time. Check
to be sure the length and size have not
been changed.
Inconsistent deposits
•
Inconsistent deposits can result if the
air pressure controlling the valve and/or
supplying the reservoir is fluctuating or if
the valve operating pressure is less than
70 psi (4.8 bar). Check to be sure air
pressures are constant and the valve
operating pressure is 70 psi (4.8 bar).
•
The time the valve is open must be con-
stant. Check to be sure the valve con-
troller is providing a consistent output.
A NORDSON COMPANY
USA: 800-556-3484 or +1-401-434-1680
Europe: 0800 585733 or +44 (0) 1582 666334
Asia: +86 (21) 5854 2345
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www.efd-inc.com
©2006 Nordson Corporation 752V-MAINT-01 v062606
