Graco EcoQuip 2 EQp Operation, Repair, And Parts page 23

Problem
Unable to fill or pressurize the
pot with water
(continued)
The blast hose recoils heavily
when the blast control switch
(B) is engaged. Large slugs
of abrasive and water are
ejected from nozzle.
The pot pressure relief valve
(K) is discharging water.
No blast air flow when the
blast control switch (B) is
engaged. The water pump
does cycle while the blast
control switch is engaged.
3A4802D
Cause
The pop-up seal does not seal
properly.
The water pressure regulator is
malfunctioning.
The abrasive ball valve was left open
during shut down.
The abrasive ball valve is worn.
The pinch hose is worn.
The fill/flush valve is open.
The water pressure regulator is mal-
functioning.
The pressure relief valve has failed.
The adjustable blast regulator is not
adjusted to the correct pressure.
The tubing to the main air regulator is
not properly connected or there are
air leaks in the fittings or tubing.
The adjustable blast air regulator is
malfunctioning.
The main air regulator is malfunction-
ing.
Solution
Make sure the pop-up is clean and free of
debris in the o-ring sealing area. Check for
proper pop-up alignment in the closed posi-
tion (there should be no gaps between the
o-ring and the pop-up). Remove the o-ring
and make sure the o-ring gland is clear of
debris. Replace the o-ring and/or pop-up if
worn.
Adjust the water pressure regulator until the
pot pressure gauge reads 185 psi (12.75
bar, 1.275 MPa). If this adjustment is not
possible, service the water pressure regula-
tor (see manual 309474).
See Shutting Down, page 17.
With the pot pressurized, the selector valve
in the BLAST position, and the abrasive ball
valve closed, engage the blast control switch
(B) and check to make sure the pump is
stalled. If the pump rod is cycling, replace
the abrasive ball valve (M).
With the pot pressurized and the abrasive
ball valve open, check to make sure the
pump is stalled. If the pump rod is cycling,
replace the pinch hose (see Replacing the
Pinch Hose, page 28).
Close the fill/flush valve.
Adjust the water pressure regulator to 185
psi (12.75 bar, 1.275 MPa). If this adjust-
ment is not possible, service the water pres-
sure regulator (see manual 309474).
Replace the pressure relief valve if weeping
occurs at or below 185 psi (12.75 bar, 1.275
MPa).
Adjust the blast regulator to the desired
pressure while the blast control is engaged.
See Tubing Schematic, page 41. Check for
leaks at connection points.
Clean or replace the adjustable blast air reg-
ulator.
Disassemble the main air regulator and
inspect components. Replace or repair parts
as necessary. See Parts, page 32.
Operation
23