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A thermometer well is provided on the right hand side of the gage base. If a glass
thermometer is preferred, one is available as an accessory under part number 2465-6.A
PRT (RTD) well is provided on the back left side of the gauge base. Either of these
methods may be used to determine gauge temperature. Pressure corrections for
temperature changes can be made according to the methods outlined in Appendix A.
Leaks in the pressure system that is used with the gauge cannot be tolerated. Small leaks
cause rapid piston fall rates and can create an error in the measured pressure. Every effort
should be made to insure a leak-free system.
Maintenance of the Gauge
Reference drawing 2465-12 in Appendix B.
Although the piston pressure gauge is not a complex instrument, certain maintenance
procedures should be followed to insure trouble-free performance.
The O-Rings (54-703-006) on the Vacuum Seal Assembly (2465-14) and the Cylinder
Housing Assembly (2460-65) have proved to be reliable and leak free. The O-Rings
should be lubricated with DuPont Krytox 240 AA Grease (45-339) after every six weeks
of operation. Replace the O-Rings if leakage occurs in the gauge.
1. To lubricate and replace the O-Ring Rotary Seal on the Cylinder Housing, remove
the two Shoulder Screws (71-103) and pull the entire O-Ring holder from the gauge
body.
2. Unscrew the Packing Nut (2460-4-15) and lubricate and replace the O-Ring.
3. Install the O-Ring by reversing the above steps. Refer to the drawings in Appendix A.
4. To lubricate and replace the drive gear shaft O-Ring seal or to lubricate the drive
gears, remove the two hex head screws that hold the Gear Support (2460-4-19) in the
gauge body.
5. Loosen the screw that holds the Hub Clamp (13-485) on the drive gear shaft and
remove the Hub Clamp. The drive gear shaft with the drive gear (permanently
attached) can then be pulled from the Gear Support.
6. After removing the Ball Bearings (5-144), the Vacuum Seal (2465-14) can be pushed
out of the Gear Support.
7. Unscrew the Packing Nut and lubricate or replace the O-Ring. Before replacing this
unit in the gauge, the drive gears should be lubricated with a mixture of Dupont
Krytox 240 AA Grease (45-339) and molybdenum disulfide.
8. The Vacuum Seal (2460-14), Packing Nut and O-Rings need not be installed in the
Gear Support (2460-4-19) unless a vacuum reference pressure is being used for
absolute pressure measurements.
9. The Ball Bearings (5-144) should be cleaned and lubricated with one drop of
DuPont Krytox 143 AZ Fluorinated Oil whenever the gauge is disassembled.
Do NOT lubricate the lower thrust bearing (2460-4-25) or the
upper thrust bearing (2460-5-6). See Drawing Number 2465-725
in Appendix B. If either of these bearings is dirty or oily, clean
them before using. To clean these bearings, rinse them with a
solvent such as acetone or high grade alcohol. Dry them
thoroughly before installing them.
W Caution
Operation
Maintenance of the Gauge
5
5-11
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