Graco 241407 Instructions-Parts List Manual page 6

Fluid Pressure Relief Valve
CAUTION
Some systems may require installation of a pressure
relief valve at the pump outlet to prevent
overpresurization and rupture of the pump or hose.
See Fig. 1.
Thermal expansion of fluid in the outlet line can cause
overpressurization. This 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 can also occur if the Husky pump is
being 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.
Install valve between fluid inlet and outlet ports.
1
Connect fluid inlet line here.
2
Connect fluid outlet line here.
3
Fig. 1
6 308797
Installation
Air Exhaust Ventilation
Be sure the system is properly ventilated for your type of
installation. You must vent the exhaust to a safe place,
away from people, animals, food handling areas, and all
sources of ignition when pumping flammable or
hazardous fluids.
Diaphragm failure will cause the fluid being pumped to
exhaust with the air. Place an appropriate container at
the end of the air exhaust line to catch the fluid. See Fig.
2.
The air exhaust port is 3/8 npt(f). Do not restrict the air
exhaust port. Excessive exhaust restriction can cause
erratic pump operation.
See Venting Exhaust Air in Fig. 2. Exhaust to a remote
3
location as follows:
1. Remove the muffler (W) from the pump air exhaust
port.
2. Install an electrically conductive air exhaust hose (X)
and connect the muffler to the other end of the hose.
The minimum size for the air exhaust hose is 3/8 in.
1
(10 mm) ID. If a hose longer than 15 ft (4.57 m) is
required, use a larger diameter hose. Avoid sharp
bends or kinks in the hose.
3. Place a container (Z) at the end of the air exhaust line
2
to catch fluid in case a diaphragm ruptures. See Fig.
2.
9073A
Read Toxic Fluid Hazard on page 3.
Read Fire and Explosion
Hazard on page 3.