Fig. 11
OXYGEN SYSTEM B-24J MODIFIED

Fig. 12
OXYGEN SYSTEM B-24D to H

SERVICING THE OXYGEN INSTALLATION IN THE
B-17, B-24 and B-29

CAUTION: Always have a reducing valve between high pressure supply cylinders and ship's oxygen system.

  1. Attach recharger hoses to cylinders of both turrets in B-17 or B-24.
  2. Open valves on both commercial, high pressure cylinders on recharger cart.
  3. Turn in reducing valve on recharging cart to 100 pounds in the low pressure gage.
  4. Insert nipple of hose from recharger cart into filler valve of plane just inside nose escape hatch (B-17) or left side of fuselage (B-24 and B-29).
  5. Fully open valve at end of hose and wait until oxygen stops flowing.
  6. Turn up reducing valve on cart to 200 pounds and allow oxygen to flow until it ceases. Turn up recharger valve to 300 pounds and again wait for ship's containers and supply pressure to equalize. Turn up recharger valve to 450 pounds and wait until oxygen flow ceases entirely.
  7. Check pressure gauges in ship to make sure that all register in the neighborhood of 425 pounds.
  8. Turn off hose valve and remove nipple from filler valve.
  9. Replace cover of filler valve.
  10. Disconnect filler hoses from turret tanks.
  11. NOTE: Purifier cartridge should be changed after discharge of every 1.6 cylinders of oxygen. (T.O. 19-1-2) If this is not observed the oxygen will contain moisture and freezing in oxygen system will occur at high altitude.

After the oxygen in the tanks has had time to cool down, pressure should be in the neighborhood of 400 pounds.

The same procedure must be employed even if one or more of the systems is already fully charged since there is no way of equalizing pressure among the different manifolds. Do not attempt to use any system in which the pressure is less than 50 to 75 pounds per square inch. Under these conditions the oxygen flow is very weak. More dangerous is the possibility of moisture getting into the oxygen line through the main recharger valve. This will result in freezing in the line or one of the regulators on the next trip to high altitude.

LEAKS IN OXYGEN LINE