Bio-Rad PDS-1000 / He™ and Hepta™ Systems - Manual (Page 42)

6.6 Unit Will Not Pressurize Gas Acceleration Tube
Probable Cause Action
1. Rupture disk not in position or Insert disk properly
not sealed by retaining cap.
2. Main cylinder valve of Helium Adjust according to Section 3.1
tank not open
3. Insufficient vacuum Examine vacuum connections (see Section 3.2)
4. Helium system leak Isolate leaks in the helium pressure regulator by
closing the helium cylinder valve and turning the
pressure-adjusting screw one turn counter-clock-
wise, then note the following:
• If the high pressure gauge reading drops, there is
a leak in the cylinder valve, inlet fitting, or high
pressure gauge.
• If the low pressure gauge drops, there is a leak in
the valve, hose, hose fitting, outlet fitting or low
pressure gauge.
• If the high pressure gauge drops, and at the same
time the low pressure gauge rises, there is a leak in
the regulator seat.
Defective regulators should be returned to Bio-Rad
Laboratories for repair. Use of a damaged regula-
tor, or one that has been repaired improperly is a
safety hazard.
5. Helium tank regulator not adjusted Adjust according to Section 3.1
correctly
6. Solenoid 3-way metering valve Connect according to Section 3.1 and 5.4
assembly not properly connected
to main unit
7. Solenoid 3-way metering valve closed Adjust according to Section 3.1 and 5.4
39