Eaton’s Carter brand part number 61657-2 is a “no-go”
type gauge designed to determine if an aircraft adapter
is safe for use. The nozzle that connects to the aircraft
adapter is designed to remain closed unless connected
to an adapter and can not be removed from the adapter
while in an open condition. This is called the “interlock”
function. It is a safety feature paramount in all nozzles.
Obviously it could be very dangerous if the interlock
feature was nonfunctional and this can occur “if’ the
nozzle or the adapter are excessively worn. The width
of the adapter slots is important to assure that the
interlock function of the nozzle is not defeated. The
Carter brand nozzle is self checking, requiring no
gauges. Refer to the service manual for the appropriate
nozzle for additional safety instructions.
The gauge is furnished with an instruction tag, both of
which are hooked to a quick disconnect attachment, so
that it is convenient for the operator to carry it on a belt
loop having it ready for use at each refueling