OPG1™ Operation and Maintenance Manual
©2000
DH Instruments, Inc
.
Page
30
4.4
PRIMING THE HYDROPNEUMATIC PUMP
If hydropneumatic pump is filled with air (cavitated), if will pump continuously when drive air is applied
without drawing oil from the tank or generating oil pressure. If you believe the pump may be
cavitated, first attempt to purge it following the procedure described in Section 2.4.3.1. If the pump
cannot be purged, use the priming by syringe injection procedure described in Section 4.4.1. If the
syringe injection procedure is not successful, consider using the internal priming procedure described
in Section 4.4.2.
4.4.1
PRIMING THE HYDROPNEUMATIC PUMP BY SYRINGE INJECTION
The hydropneumatic pump injection priming procedure is only required if the regular purge
procedure fails (see Section 2.4.3.1).
Numerical references in this section refer to Section 4.2, Figure 9.
To prime the pump with the syringe proceed as follows:
Back off the OPG1
DRIVE SET regulator
to zero by turning it fully CCW.
Open
INLET valve
and
OUTLET valve
.
Remove oil tank cover (2).
Install 2-104 O-ring on tip of 10 cc syringe (both supplied in OPG1 accessory kit, see
Section 2.1.2).
Fill syringe with oil from the tank.
Insert the tip of the syringe into the tank pump draw port (4) and press so that the O-ring
seals against bottom of tank.
Increase pump drive air pressure by rotating
DRIVE SET regulator
CW until the pump
begins to cycle. When pump begins to cycle, press syringe plunger, injecting oil
into pump. Continue until oil returning through the tank oil return overflow tube (3) is free
of air bubbles. Note that in some cases, air free oil will return before trapped gas is
expelled from the pump.