OPG1™ Operation and Maintenance Manual
Page 17
©2000
DH Instruments, Inc
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Opening the
INLET valve
opens the test system to the output of the
hydropneumatic pump. As long as the
INLET valve
is open, the pump will cycle until
it stalls. To avoid accidental overpressure of the items to which OPG1 is connected,
always adjust the
DRIVE SET regulator
so that the hydropneumatic pump output will be
lower than the maximum desired pressure BEFORE opening the
INLET valve
(see Sections 2.4.2 and 3.2.1).
Always adjust the DRIVE SET regulator so that the hydropneumatic pump output is not
higher than the maximum desired pressure BEFORE opening the INLET valve. Failure to
adjust the DRIVE SET regulator increases the chances of accidental overpressure of the
system connected to OGP1.
•
When using INLET valve, pressure rate of rise may increase very rapidly after system
is primed. Exercise extra caution when setting the first pressure coming off zero.
When test is < 400 MPa (6 000 psi), consider using INLET valve to prime only (only until
pressure starts rising), then use PDVV for all pressure control.
•
The
and
push button valves can increase pressure very quickly. Observe pressure
evolution carefully when operating these valves (see Section 3.2.3).
•
Check oil tank level before operating and regularly during operation. Operating with an
empty oil tank will cause the hydropneumatic pump to draw air and require priming it (see
Section 4.4).
•
Put the PDVV in the
START
position when starting a calibration or test sequence (see
Section 3.2.3).
•
Systems and DUTs connected to OPG1 should be purged of air before they are
pressurized (see Section 3.2.5).
•
If there is an open point in the system to which OPG1 is connected that is lower than the
OPG1 tank, oil will run out of the OPG1 tank through this point when the
OUTLET valve
is open. Close the
OUTLET valve
when a point lower than the tank is open.
•
The fluid head reference level of OPG1 when the
OUTLET valve
is open is the top of the
tank return overflow tube. Consider the difference between this reference level and the
reference measuring device reference level to avoid zero gauge points that are
inconsistent with other pressure points (see Section 3.2.6).