Robwen

Operation:Definition
If, when water pressure is applied, you can see this shaft going back and forth
then it is operating.
If the unit is not operating, then see Section 1.
If the unit is operating but not pumping foam then see Section 2.
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Section 1
The unit is not operating
Is your water filter element clogged?
See page 3 for backflushing and, if
necessary, cleaning or replacement of filter
element.
Are there protruding O-rings on the unit?
Is it leaking water (See photo on page ???)
Unit has been frozen, please send back for
non-warranted repair
Is the OP spool stuck?
See page 8 for cleaning procedure
Is the Manifold spool stuck?
See page 11 for cleaning procedure
Is the crank pin between the collars?
See page 16 for procedure to set crank pin
correctly
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Is your water filter element
clogged?
1) Turn the lever to the discharge position and hold for 30 seconds. This backflushing
should clean the element. If the unit still fails to operate then proceed to step 2.
2) Unscrew filter cover. (The O-ring seal will cause it to drag at first)
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3) Remove filter element as shown
4) Robwen recommends the use of a brass bristled wire brush to clean the filter
element as shown (Too stiff a wire on the brush will damage the filter element)
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5) Holding the brush as shown move in back and forth motion end to end to get
dirt out of screen.
6) Rinse with water as shown and reassemble.
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Are there protruding O-rings on the unit?
or
Is it leaking water
Where arrows are pointing?
Then send to Robwen for repair. Unit is damaged.
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Is OP spool stuck
Remove the brass hex nut (Drawing “Ref J” - J13) from the operating valve.
1. Remove one of the four allen bolts from the top of the operating valve.
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2) Use the allen bolt as a tool to remove the J11 spool portion of the operating valve. The
J11 spool has been drilled and tapped to accommodate the allen bolt.
2. With the J11 spool removed, set the panel as shown below and perform the
normal flush procedure. (Page 10) There will be a lot of water flow out of the
spool cavity. Also you will want to rinse off the spool.
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3) Reinstall the spool with the tapped end facing out. Put the hex nut back and
return the allen bolt to its location, do not over tighten.
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Is Manifold spool stuck?
1) Locate manifold block
2) Using 5/32 allen wrench, unscrew 2 screws on the top of the manifold block
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3) Slide Manifold block away from operating valve body. It might be tight at
first because of O-ring pressure.
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4) Be careful not to lose O-ring or when re-assembled, it will leak and
degrade the performance of the unit.
5) Pull connecting tube from body to expose piston. (O-ring pressure will
make it a bit tight.)
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6) Using screw that you removed before as a removal tool, remove spool
from body.
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7) Rinse body and spool with warm water to remove any residue.
8) Re-assemble
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Is the crank pin between the
collars?
1)
Notice how the crank pin is outside of the shaft collars
2) Remove the four allen cap screws from the operating valve body.
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3) Slide operating valve body off of lower assembly
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5) You will see that the collars will be to shifted to one side or the other.
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6) You will need to move them to the approximate center. IMPORTANT Make sure the
O-rings have not come off of the bulkheads.
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7) With the operating valve off, note the position of the crank pin. It will look similar to
this or it could be 180° off depending on which collar it has skipped over.
8) Move crank pin to position shown below
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9) Re-assemble the operating valve making sure that the crank pin is in between the shaft
collars. Slide the operating valve back into place, and tighten the 4 screws.
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Section 2
The unit is operating but not pumping foam
The unit does not prime.
Problem
Solution
Do you have enough GPM and PSI to
run unit?
Make sure you have foam and that the
valves are open
Make sure that there are no air leaks
that would compromise the suction of
foam into the unit.
Minimum requirements for system
operation are 80 PSI @ 5 GPM. Check
the pump to tank valve to make sure
that it is not fully open. This can
reduce water pressure below operating
minimum.
Are the panel valves in the correct
position?
See page 23 for correct position.
Have the handles on the panel been
removed?
See page 24 for correct orientation
Is your foam tank full?
Does the unit leak?
Is your foam filter element clogged?
See page 26 For element replacement.
Quad valve may be stuck. Flush
thoroughly and, if possible, flush with
warm water. (Foam has probably dried
and caused the quad valve to stick) If
this fails, send unit back to Robwen for
repair. This is why flushing after each
use is so important!
If all above is correct and it’s still not
pumping foam
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Are handles in correct position for foam
1) Make sure that the system is primed. All 4 handles should be in the position
indicated below.
2) If we are priming correctly you should see a small amount of foam concentrate
dumping out on the ground. When this happens set the supply valve and flush
valve in the following position as indicated below, and dial in the desired
percentage on the metering valve.
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Replacing handles in correct
orientation after removal
1) With the handles removed, you will see that there are flats on both sides of all
three valve stems. On one side of all three valve stems there is red paint. This
red paint should be at 12:00 orientation on all three valves stems.
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2) Replace handles as shown below.
3) Tighten the allen cap screw on back side of handles against flat. Also tighten
the acorn nut on the on/off handle.
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Cleaning the Foam Filter Element
1.) Locate the foam filter
2.) Unscrew the top to expose the filter element
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3) Pull the element out of the housing.
4) Clean element with hot water and brush and replace. Make sure O-ring on
bottom of element is not torn.
If the element is too clogged to clean, replace the element (See drawing Ref “N”
for part number)
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