SECTION IX
9.0
GAUGING TAPE REPLACEMENT
(With or without new sensor attached):
The gauging tape used for the Trimode closed gauging system is similar but not interchangeable
with the gauging tapes used for restricted gauging systems.
The tapes used are bright white faced steel core type, which have been encapsulated with a
tefzel jacket. (Tefzel is a registered trade name of the DuPont Corporation). The taps are
terminated at the display electronics hub PCB module connection points, by soldered leads
within the tape reel internal core. The sensor is connected to the tape by means of a quick
connect plug to the tape socket plug.
As with all tefzel coated MMC gauging tapes, the outer surfaces are factory treated to render
the surfaces of the tapes with anti-static properties.
The patented process to achieve the desirable anti-static condition is not defeated by tape
wiping or cleaning with standard petroleum-based solvents.
Gauging tape replacement is not difficult, but requires careful attention to the travel path of the
tape as it exits from the tape reel assembly, passes over the interior guide rollers, cursor pin
assembly, anti-chafing rollers and on through the wiper housing.
9.1
To replace a tape, remove the vapor valve barrel, tape wiper assembly, stub barrel
connector and main reel housing cover.
9.2
With the main reel cover removed, the tape reel and tape pay-out through the wiper
housing can be seen. Take careful note of how the tape is directed around the various
roller and guides. In particular, note the tape path between the upper right-hand roller, the
guide roller just below it, cursor pin assembly, and tape wiper split ring bushing.
9.3
With the above in mind, or recorded with a simple hand sketch, the screws holding the
reel hub cover can be removed. The reel hub cover is both a reel interior cover, and also
the reel drive shaft to reel driver. The underside of the cover has a crossbar, which
couples it to the reel drive shaft assembly. The coupling action is accomplished by means
of the cover cross bar engaging the slotted ends of the drive shaft assembly.
With the reel hub cover removed, note that the outer reel plate is still retained to the reel
hub core by a single flat head screw.
Note that directly opposite the flat head screw (180° away) a small pinhead can be seen in
a reel plate hole on the same screw hole diameter as the flat head screw. Also, note that
the screw hole pin, is at this time, aligned with drive shaft coupling slots.
The interior electrical connector hub end of the gauging tape is not also in view. Note the
placement of the terminating epoxy molding piece at the end of the tape within the hub
core. Also, note the three wires leading to a connector and a separate black ground wire
emanating from the molding.
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