(3) Install sight gage body (32) to tank with
pressure from above the tank baffle. When the
washers (31) and screws (30).
pressure differential equals or exceeds 20 psi, the
yellow button on the differential pressure indicator
(4) Start up operation of filter-separator as
described in paragraph 2-2.
"pops up". When the pressure differential equals or
exceeds 3.5 psi, the red button "pops up".
a. Removal. Remove the differential pressure
indicator (6, fig. 1-2, sheet 1 of 2) in the following
a. Removal. Remove the sight gage assembly
manner.
(29, fig. 1-2, sheet 2 of 2) in the following manner.
(1) Stop pumping unit. Shut off up-stream
(1) Stop the pumping unit. Shut off up-stream
and down-stream system valves.
and down-stream system valves.
CAUTION
CAUTION
Depressurize t h e t a n k b e f o r e a t -
Filter-separator tank must be isolated
tempting removal of the differential
from the fuel system and depressurized
pressure indicator.
before attempting removal of the sight
gage.
(2) Slowly open air vent valve (5) to relieve
pressure in filter-separator. Open water drain valve
(2) Very slowly open air vent valve (5, fig. 1-
2, sheet 1 of 2) to relieve pressure in filter-
(36, fig. 1-2, sheet 2 of 2) and drain tank.
separator. Open water drain valve (36, fig. 1-2,
(3) Disconnect coupling nuts (4, fig. 4-2)
sheet 2 of 2) and drain tank.
from elbows (1) and connectors (6). Remove
tubing (2 and 3). Remove elbows and connectors if
(3). Remove screws (30), washer (31), and
remove sight gage body (32) and ball (34). Remove
damaged. Remove screws (8) and washers (9 and
and discard gasket (33).
10) to remove differential pressure indicator (7).
b. Cleaning. Remove all dust, dirt, and film
from sight gage with a soft bristle brush, being
Key to figure 4-2:
careful not to damage the gage.
1 Elbow
c. Inspection of Sight Gage. Inspect gage for
2 Tubing assembly
cracks, nicks, or other damage. Replace sight gage
3 Tubing assembly
4 Nut, coupling
if necessary.
5 Tubing
d . I n s t a l l a t i o n . Install sight gage in the
6 Connector, male
following manner.
7 Differential pressure indicator
(1) Install new gasket (33). Apply silicone
8 Screw, machine
compound MIL-S-8660.
9 Washer, flat
10 Washer, lock
(2) Place ball (34) into sight gage body (32).
