Sufficient data shall be obtained and curves plotted to demonstrate
compliance with the model specification.
4.6.3 Suction Pressure Loss - (Perform only if required by the model specifi-
The ejector shall be installed in a fuel tank to simulate aircraft
installation, with the nozzle port (Pi) blocked.
The flow rate through the
ejector shall be varied from O to design value by varying discharge pressure
(Pal) at a constant secondary flow inlet port pressure (Po). The pressure change
(Pd-Po is to be recorded and plotted. The pressure drop shall be as specified
in the model specification.
4.6.4 Pump Down - The ejector discharge port shall be closed. Po and Pi shall
be adjusted as specified in the model specification. The discharge port shall
be opened, starting the ejector. The liquid level shall be permitted to drop as
the ejector operates. The point at which Wt equals Wn is the minimum pump down
level. This level is to be specified in the model specification.
4.6.5 Altitude - The ejector pump shall function satisfactorily when subjected
to both transient altitude tests and steady state altitude test. The Transient
Test varies the pressure altitude in the test tank from sea level to maximum
obtainable within a time schedule, simulating air vehicle climb to altitude with
maximum obtainable within a time schedule, simulating air vehicle climb to
altitude with maximum Reid Vapor Pressure (RVP.) fuel (least fuel weathering ).
The Steady State Test holds the pressure altitude constant while checking the
ejector pump performance, simulating the air vehicle at constant altitude with
maximum RVP fuel.
Transient Test - This test shall be conducted with a sample of the
applicable fuel with maximum RVP (as defined by the applicable fuel specifica-
tion)* in the quantity required by the model specification. Fuel temperature
shall be maintained at 57°C (135°F) unless otherwise specified. Total nozzle
pressure (Pi) shall be held at the specified optimum design point. Total dis-
charge pressure (Pal) shall be decreased at each altitude until limit flow occurs.
Sufficient test data shall be taken to define the limit flow ratio at each
altitude called for in the model specification.
b. Steady State Test - This test shall be conducted with a fresh sample of
the applicable fuel with maximum RVP (as defined by the applicable fuel specifi-
cation)* in the quantity required by the model specification. Test parameters
PO, (Pi - Po} and fuel temperature shall be the same as test (a) of this sec-
tion. A climb to the maximum obtainable pressure altitude for the RVP and test
fluid temperature shall be made from sea level within the time required in the
model specification. At the test altitude Pd shall be varied from its maximum
to minimum value. This sequence shall not exceed 120 seconds. Identical sequen-
ces shall be taken at altitudes from maximum obtainable down to sea level in
3,000 meter [9,840-foot) increments starting at the service ceiling and progress-
ing down to sea level.