DH Instruments PPC2 AF - Purge Function

PPC2 AF OPERATION AND MAINTENANCE MANUAL
© 1998 DH Instruments, Inc. Page 38
3.2.8.3 PURGE FUNCTION
For the purge function to operate, the Self Purging Liquid Trap (SPLT) must
be correctly installed in the line connecting the PPC2 AF TEST port to the
device or system under test. For information on SPLT installation see
Section 2.3.5.1.
Pressing the VENT direct pressure control key (see Section 3.1.2.2) from the
LEAK CHECK screen will cause the PURGE function to execute.
Execution of the PURGE function is automated and proceeds as follows:
1. If current pressure is greater than 100 psi (700 kPa) gauge, pressure is
controlled down to less than 100 psi (700 kPa) gauge.
Ideal pressure from which to execute PURGE function is 150psi (1MPa). Avoid
executing PURGE function from pressures above 150psi (1MPa).
2. Pressure control stops and a 5 second wait occurs.
3. SPLT exhaust valve is opened.
4. Waits until pressure is less than 3 psi (20 kPa) gauge or 16 psi (110 kPa)
absolute.
5. Vent valve is opened with SPLT exhaust valve left open.
When the PURGE function is initiated, if the current pressure is over 100 psi (700 kPa)
gauge, the display is:
1. Current measured pressure and pressure
units.
2. Current reference pressure transducer and
range.
3. Indication that PPC2 AF is reducing pressure
to the purge pressure of less than 100 psi
(700 kPa) gauge.
163.46 psi a H3
Descending to purge
Pressing ESCAPE at any time during purge routine execution causes the
purge function to abort and returns to the leak check screen (see Leak Check
Screen above).
Once the current pressure is, or if the purge function was initiated, under 100 psi
(700 kPa) gauge the display is:
1. Current measured pressure and pressure
units.
2. Current reference pressure transducer and
range.
3. Indication that PPC2 AF is preparing to open
the SPLT exhaust valve.
89.74 psi a H3
Preparing to purge