18.104.22.168 Underwing (single point) fuel servicing operations. The pumping system shall
function as follows:
(a) Refuel from the tank through the filter/separator, the contamination monitor, the
meter, the 2-inch pressure servicing hose, and the 2.5 inch underwing nozzle at any
flow rate from zero to 200 gpm, while automatically maintaining 50 ± 5 psig nozzle
pressure at the inlet side of the nozzle. Once the pumping system pressure controls
have been adjusted, the flow rate shall be regulated on demand ahead of the
underwing nozzle. The system shall automatically recover from an externally
induced no-low condition to full flow within 15 seconds after the full flow demand
condition has been re-established. During pressure (underwing) refueling operation,
the pumping system shall limit the total pressure at the inlet to the underwing nozzle
to 120 psig at any initial flow rate from 0 to 200 gpm when the flow is shut off in
(b) Defuel from the aircraft through the 2.5 inch underwing nozzle, the 2-inch hose, the
filter/separator, the contamination monitor, and into the tank at flow rates up to
22.214.171.124 Closed-circuit fuel servicing operations. The pumping system shall refuel from
the tank through the filter/separator, the contamination monitor, the meter, the 2-inch hose, and
the 1.5 inch closed-circuit nozzle at any flow rate from zero to 100 gpm, while automatically
maintaining 15 ± 2 psig nozzle pressure at the nozzle outlet.
126.96.36.199 Self-loading operation. The truck shall be capable of self-loading (loading by use
of the on-board pumping system) at a rate of not less than 200 gpm. Self-loading shall be
accomplished through use of the suction stub specified in 3.5.21 and the 10-foot hoses specified
188.8.131.52 Recirculation operations. The truck shall have the capability of recirculating
contaminated fuel through the filter/separator, the contamination monitor, and back into the tank.
The 2.5 inch underwing nozzle on the 2-inch hose shall be connected to a fitting with a check
valve on the driver's side of the tank to perform fuel recirculation.
3.8.5 Type III fuel system components.
184.108.40.206 Pump bypass valve and line. An automatic pump bypass valve and line shall be
an integral part of the flow control system. The pump bypass valve shall serve to divert excess
fuel flow to the inlet side of the pump to control fuel pressure. The bypass line shall be located
upstream of the filter/separator and contamination monitor. The bypass system shall prevent
engine speed changes of more than 300 rpm between the full-flow and no-flow for any pumping
mode, except defuel.
220.127.116.11 System tank return line. In addition to the pump bypass, a tank return line shall
be provided. The return line shall allow return of fuel to the tank during defuel and during use of