Pressure Relief Procedure; Flushing - Graco HFRL Setup And Operation Manual

Operation

Pressure Relief Procedure

NOTICE
The fittings on the pressure relief hoses are zinc
plated carbon steel. The hoses are cured with sul-
fur. Check your materials for compatibility with zinc
plating and sulfur before reusing any material that
passed through them, as it may inhibit curing.
1. Shut off feed pumps and agitator, if used.
2. Turn PRESSURE RELIEF/DISPENSE valves (SA,
SB) to PRESSURE RELIEF/CIRCULATION
Route fluid to waste containers or supply tanks.
Ensure gauges drop to 0.
SA
3. For models with an dispense valve with a safety
lock, engage gun safety lock.
4. Relieve pressure in dispense valve. See dispense
valve manual.

Flushing

Flush equipment only in a well-ventilated area. Do not
dispense flammable fluids. Do not turn on heaters
while flushing with flammable solvents.
• Flush out old fluid with new fluid, or flush out old
fluid with a compatible solvent before introducing
new fluid.
40
• Use the lowest possible pressure when flushing.
• All fluid components are compatible with common
solvents. Use only moisture-free solvents. See
Accessories on page 136 for list of wetted compo-
nents to verify compatibility of solvent with wetted
materials. See solvent manufacturers information
for material compatibility.
• To flush feed hoses, pumps, and heaters separately
from heated hoses, set PRESSURE RELIEF/DIS-
PENSE valves (SA, SB) to PRESSURE RELIEF/CIR-
CULATION
SA
N
.
• To flush entire system, circulate through gun fluid
manifold (with manifold removed from gun).
• To prevent moisture from reacting with isocyanate,
always leave the system dry or filled with a mois-
SB
ture-free plasticizer or oil. Do not use water. See
Important Two-Component Material Information
on page 14.
ti9879a1
• Solvent pails used when flushing: follow your local
code. Use only metal pails, which are conductive,
placed on a grounded surface. Do not place pail on
a nonconductive surface, such as paper or card-
board, which interrupts grounding continuity.
• To maintain grounding continuity when flushing or
relieving pressure, hold a metal part of dispense
gun firmly to the side of a grounded metal pail, then
trigger gun.
. Flush through bleed lines (N).
SB
N
ti9880a1
3A2175Z