Model H1301 Recovery and Recycling System
Installation, Operation and Maintenance Manual
Revision-L September, 2019
Page 68 of 105
VII. System Maintenance Procedures
M. Pressure Controller Adjustment and Calibration (continued)
2. Pressure Loop System Calibration
The following procedure will detail the routine maintenance calibration procedure that is
possible without accomplishing component level maintenance. If satisfactory operation is
not obtained using this procedure then verify component operation set forth in the
following sections for troubleshooting and pressure controller calibration.
Required Materials:
Calibrated Pressure Gauge 0-300 psi in 1-psi increments ¼% accuracy
¼” Refrigeration Service Hose
Commercial Grade Nitrogen Gas Source Regulated to 250 psi
a. Connect a source of clean dry nitrogen gas regulated to 250 psi to the front panel
Inlet Port of the machine.
b. Open the nitrogen source to the machine.
c. Briefly loosen the nitrogen connection at the Inlet Port to purge air out of the
connecting plumbing. Then retighten the connection.
d. Open the manual Inlet Valve MV-1 of the machine.
e. Place the front panel Power Switch to the ON Position and allow the machine to
cool to the appropriate setting for the type of agent in the machine.
f. Connect the pressure gauge to the nitrogen vent port of the machine.
g. Place the front panel N2 Switch to the ON position. The pressure in the process
tank will now be indicated by the pressure gauge connected to the nitrogen vent
port.
h. The pressure in the process tank may now be controlled. Reduce the pressure in
the tank by loosening the connection at the pressure gauge to vent the tank.
Increase the pressure in the tank by operating the Inlet Valve Switch on the front
panel. Use this method to gain a 5 psi indication on the pressure gauge
connected to the nitrogen vent port. DO NOT RELEASE THE PROCESS TANK
PRESSURE ABOVE THE TEMPERATURE CONTROLLER ALARM #2 SETTING
FOR THE SPECIFIC TYPE OF THE AGENT IN THE MACHINE THIS WILL
RESULT IN EXCESSIVE AGENT LOSS.
i. Observe the display of the front panel pressure controller. Adjust the zero
potentiometer of the controller to obtain a pressure controller display of 20.
NOTE: Add 15 psi to the reading on the external pressure gauge to determine what the
pressure controller display should indicate. For example: ideally, the pressure
controller should display 50 when the external gauge indicates 35 psi.
NOTE: The accuracy of the pressure controller may now be verified by increasing the
pressure in the process tank in steps and comparing the external pressure gauge with
the display of the pressure controller. The pressure controller should be +/- 1 psi from
20 to 25 psi display indication and +/- 5 psi across the 200 psi range of the system. It is
most important to have the best accuracy from the 20 to 50 psi range so that the
pressure controller alarm outputs will operate at the proper pressures for vent
operations.
j. Place both the N2 Valve and Inlet Valve switches to the AUTO positions.
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