Magnum Venus Plastech DP-1000 (EPO3) - Manual (Page 18)

(Figure 14. Assemble Turbulent Mixer) (Figure 15. Insert Injector)
Recheck Pressure
 Set MAIN PRESSURE to estimated operating pressure of the unit.
 Start at 30psi for RTM and 50 psi for spraying.
 Pull gun trigger and operate until pressure stabilizes.
 Check pressure gauges mounted on the front panel.
 If one gauge reads more than 200psi higher pressure than the other, increase resin heater on
that side of the machine by turning block heat knob to an increased value position. Hold the
PRE-HEAT button for two minutes before operating the unit again.
 If pressure difference is still too great, heat material containers until both pump gauges read
within 200 psi while recirculating. It may be necessary to re-adjust the block heat until the
temperature stabilizes.
It may be impossible with some materials to find the correct ratios to achieve balanced fluid pressures. When
you have installed the smallest or largest injector to adjust pressure and have heated the material on the high-
viscosity side to 150
F (or highest temperature recommended by material supplier) you may have to
compensate for pressure differences with procedures described in section 5, “Correct Pressure Drift.”
Spray a test sheet while a helper watches both pump gauges to monitor pressure differences.
If the variable-stroke pump pressure drops more than 200 psi below the fixed pump’s pressure during the
initial pump stroke, adjust “PUMP H” (variable-ratio pump) recirculation pressure with recirculation ball-
valve on INLET panel before switching to operating mode.
Note: If pressures differ over 200psi, see “Correct Pressure Drift.” If pressures do not differ by more than 200
psi, in Section 5, “Change to Operating Mode.”
Correct Pressure Drift
WARNING: Never allow Pump Pressure To Exceed 1200 psi Or Heaters May Rupture!
If operating pressures differ too much (over 200 psi) during initial pump stroke, use the following procedure:
 Operate unit at recirculation pressure and slowly throttle down recirculation valve on the INLET panel
which controls flow from the variable-
ratio pump known as “PUMP H.”
DANGER: Never Operate Unit Without Accumulator Safety Cover!
 Watch pressure gauge on the variable-ratio pump. When this gauge reaches approximately 200 to 300
psi greater than “PUMP R,” turn RECIRCULATION PRESSURE switch to “OFF” position. This
procedure may be n
ecessary to build full operating pressure in “PUMP H” accumulator. “PUMP H” has
a shorter stroke than “PUMP R” and therefore may need this pre-pressurizing procedure in order to
achieve full flow immediately upon activating the gun.