User's Manual

Installation
14 313597E
Fluid Pressure Relief Valve
Fuel Dispense Systems (Model 647648)
Evacuation and Transfer Systems (Model 647016)
Fuel dispense model 647648 requires a pres-
sure relief valve (S), Graco part 24B910,
which is supplied with the pump, to prevent
fluid pressure from exceeding 50 psi (350 kPa,
3.5 bar). See FIG. 5, page 13.
Recommended air operating pressure is 40
psi (280 kPa, 2.8 bar) or less. As the air inlet
pressure approaches 50 psi (350 kPa,
3.5 bar), the relief valve will open and vent
fluid. Vented fluid must be routed to a con-
tainer in a non-hazardous location.
FIG. 6. Optional Fluid Pressure Relief Kit 238428, for Model 647016
(not acceptable for fuel dispense application)
Some evacuation and transfer systems may
require installation of a pressure relief valve at
the pump outlet to prevent overpressurization
and rupture of the pump or hose. Graco Kit
238428 is available. See FIG. 6. Relief pres-
sure is between 150 and 180 psi (1.03
MPa-1.24 MPa, 10.3-12.4 bar).
This kit is not for use in fuel dispense appli-
cations, which require pressure relief at 50 psi
(350 kPa, 3.5 bar). Order a fuel dispense pump
(Model 647648), which is equipped with pres-
sure relief valve 24B910. See Warning above.
Thermal expansion of fluid in the outlet line
can cause overpressurization. Thermal
expansion can occur when using long fluid
lines exposed to sunlight or ambient heat, or
when pumping from a cool to a warm area (for
example, from an underground tank).
Overpressurization also can occur if the
Husky pump is used to feed fluid to a piston
pump, and the intake valve of the piston pump
does not close, causing fluid to back up in the
outlet line.
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Pressure
Relief Kit
1
Apply thread sealant on threaded con-
nections and install kit between fluid
inlet and outlet manifolds.
Connect fluid inlet line in one of the
optional ports.
2
Connect fluid outlet line in one of the
optional ports.
3
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