HP 5890 SERIES II Service Manual page 186

10. Slide the rear cover towards the rear of the instrument.
USE PROPER EYE PROTECTION WHEN WORKING WITH CRYOGENIC FLUIDS
UNDER PRESSURE.
11. Shut off the cryogenic fluid supply.
12. Slowly loosen the cryogenic fluid supply, at
the valve, to release any residual pressure.
13. Disconnect the cryogenic fluid supply at its
fitting to the valve.
14. Trace and free the valves wire harness to con-
nector J9 on the main PCB.
15. Disconnect connector J9 from the main PCB by pulling it straight out of its receptacle.
16. Remove the valve assembly from the outside wall of the oven by removing three nuts (and as-
sociated washers) from around the edge of its mounting bracket.
17. Withdraw the valve assembly from the side of the instrument, being careful not to bend or dam-
age the nozzle assembly.
18. Separate the valve body from its mounting bracket by removing two screws.
19. If only the cryogenic nozzle is being replaced, proceed as follows:
a. Remove the nozzle (notice its position with respect to the valve assembly) from the valve
body and discard.
b. Wrap the threads of the new nozzle with Teflon pipe tape being careful not to cover the first
two threads of the nozzle.
Artisan Scientific - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisan-scientific.com
CRYOGENIC FLUID SUPPLY
FITTINGS (ITEM USED
DEPENDS ON FLUID EMPLOYED)
SCREW
NUT
WASHER
NOZZLE (TYPICAL)
SVC 5- 24
MOUNTING BRACKET
CRYOGENIC
VALVE