Spacelabs BleaseSirius - Mechanical Hypoxic Guard Regulators, Adjustment and Output Check

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1. Remove the smaller of the fl ow tubes for the gas to be inserted (Removal
of Flow Tubes, Section 5.10).
2. Remove the spring and lower insert from the block (Figure 63).
3. Ensure that all fl ow control valves are set minimum and turn on the
machine.
4. Pour a small amount of leak detector fl uid such as ‘Snoop’ into the insert
bore of the block (in the absence of ‘Snoop’ plain water is effective) if the
valve is not sealing there will be bubbles visible in the fl uid, if there are no
bubbles then the valve is sealing correctly.
5. If there are any bubbles, then the valve stop must be adjusted. The stop
collars of the two valves differ slightly in that the nitrous oxide valve collar
is also the drive gear. Both versions have two Allen grub screws holding
them to the valve shaft.
6. To adjust the valve stop, slacken the grub screws slightly and gently turn
the valve shaft till no bubbles are present and tighten the collar grub
screws.
7. Slightly open and close the valve a couple of times and check that when
the valve is shut there are no bubbles visible.
8. Carefully dry out the insert bore and open the valve to ensure that any
fl uid is blown out. The glass fl ow tube, the insert and spring can then be
replaced.
5.5 Mechanical Hypoxic Guard Regulators, Adjustment and
Output Check
Do not adjust regulators if previous checks found the hypoxic
guard to be within specifi cation because changes in pressure
settings will adversely affect the calibration.
If, due to damage or wear, it is deemed necessary to replace the hypoxic guard
valve block, you can order a calibrated unit which will be supplied with a test
sheet. This test sheet gives the pressures to which the secondary regulators
should be set.
Detailed Repair Procedures