Graco EcoQuip 2 EQs Instructions Manual page 33

Problem
While in BLAST
mode, with the blast
control switch (B)
engaged, air is flowing
from the nozzle but
little or no abrasive is
flowing from the
nozzle.
3A7467C
Cause
The abrasive ball valve
is closed.
The abrasive metering
valve is not properly
set.
The pot does not have
a sufficient amount of
abrasive.
The pinch valve does
not open.
There is an obstruction
inside the pot or inside
the abrasive hose
between the pot and
the enclosure.
The pot pressure is too
low.
The blast pressure is
too high.
See Setup, page 16.
See Setup, page 16.
See Refill Pot with Media, page 21.
Engage the blast control switch (B) and check for actuation of the
pinch valve. If there is no actuation, disconnect the orange tubing
at the pinch valve. If the pinch valve opens and source air is
coming from the orange tubing, confirm that the tubing is correctly
routed. If the pinch valve does not open, replace it. If the pinch
valve opens and there is no source air coming from the tubing,
inspect the mufflers on the 4-way valve for debris. If debris is not
present, clean or replace the 4-way valve.
Follow Drain the Pot, page 27, followed by the Installation, page
12. With the abrasive hose disconnected, inspect the interior of the
pinch hose for obstructions or debris and replace if necessary (see
Replace the Pinch Hose, page 38). Remove the tri-clamp from
the bottom of the pot. Inspect the bottom of the pot and the
abrasive hose for obstructions or debris.
With the blast control disengaged, allow the pot to pressurize and
wait for the pump to stall. If the pot pressure gauge does not reach
185 psi (12.75 bar, 1.275 MPa), see the "Unable to fill or
pressurize the pot with water" problem listed on this table.
If the blast pressure gauge reads 160 psi (11.03 bar, 1.10 MPa) or
greater, it may not be possible to achieve than 15 CPM on the
MediaTrak. This is more common with fine mesh abrasive usage.
Decrease the blast pressure to 100 psi (6.9 bar, 0.69 MPa) to see
if CMP can be increased.
Troubleshooting
Solution
33