Aircraft-Mounted Oxygen Regulators
The MD series regulator is being used in
several multiplace naval aircraft. There are two
types of regulators in this series—the MD-1 (low-
pressure) and MD-2 (high-pressure). The only
difference found in these regulators is operating
pressure. The operating pressure of the MD-1
regulator is 50 to 500 psi. The pressure gauge reads
0 to 500 psi. The operating pressure of the MD-2
regulator is 50 to 2,000 psi. The pressure gauge
reads 0 to 2,000 psi.
The following controls and indicators are
located on the front panel of the regulator
(fig. 4-13). The small oblong-shaped window area
on the left side of the panel marked FLOW
indicates the flow of oxygen through the regulator
by a visible blinking action. The pressure gauge
is found on the upper right of the panel and
indicates inlet pressure to the regulator. The
regulator has three control levers. A supply valve
controller lever, located on the lower right corner,
is used to control the supply of oxygen to the
regulator; a diluter control lever, located on the
lower center of the panel, has two positions—
100% OXYGEN and NORMAL OXYGEN; an
emergency pressure control lever, located on the
lower left of the panel, has three positions—
EMERGENCY, NORMAL, and TEST MASK,
and with the deluter lever in the 100% OXYGEN
position, the regulator delivers 100 percent oxygen
upon inhalation by the user. In the NORMAL
OXYGEN position, the regulator delivers a
mixture of air and oxygen with the air content
decreasing until a cabin altitude of approximately
30,000 feet is reached. Above this altitude,
100-percent oxygen is delivered to the user upon
inhalation.
With the emergency pressure control lever in
the EMERGENCY position, the regulator delivers
positive oxygen pressure to the outlet at altitudes
when positive pressure is not automatically
delivered. In the TEST MASK position, oxygen
is delivered to the mask under pressure too high
to breathe and is used for checking the fit of the
mask. The switch must be in the NORMAL
position to assure normal system operation.
Refer to figure 4-14 for the operation of an
MD type regulator.
1. Supply oxygen entering through the oxygen
inlet (1) is filtered and passes through the manifold
Figure 4-13.—Regulator operating controls and indicators.
4-18
