NOTE
e. Disconnect tee-to-push valve (6) and filter-to
Refer to parts list for Figure 5-9 for
metered-orifice (7) connecting tubes from tee (13) in
part numbers and contents of
bottom of pneumatic dump valve.
Repair Kits available for use on the
f. Back off fitting nuts (14) and unscrew tee (13),
filter and separator assembly.
together with metering orifice (12), from bottom of
pneumatic dump valve and nut (15). Remove tube fitting
4.12.4 REASSEMBLY (Refer to Figure 5-9.)
gasket (16).
a. Position gasket (18) and filter element (15) against
g. Loosen clamp
(7,
5-9)and
remove
Inner surface of tank cap (13) and secure in position with
complete assembly.
washer (17) and new screw and plug assembly (16).
b. Lubricate gasket (14) with pneumatic system
4.12.2 DISASSEMBLY. The filter and separator assembly
grease (Specification MIL-L-4343) and place gasket in
and pneumatic dump valve should be disassembled only
groove around tank cap (13). Screw cap into shell (20)
when obvious indications of damage, malfunction, or
until seam is closed.
improper operation are observed.
Such indications
c. Install rupture discs (12), disc rings (11), and disc
include a burst rupture disc, air leaks, excessive moisture
ring retainers(10) in ports in tank cap (13). Tighten
in high pressure discharge air, and Improper operation of
retainers with a torque of 350 pound-inches.
the pneumatic dump valve.
Observe the following
disassembly procedure (see Figure 5-9):
d. Install pipe plug (9) in center port of tank cap (13).
e. Test partially assembled filter and separator for
a. Unscrew pneumatic dump valve (items 1 through
leakage in accordance with Instructions in paragraph 4.12.
6) from bottom of separator shell (20).
5 before continuing with reassembly.
b. To disassemble pneumatic dump valve, unscrew
f. After completing leakage test, wrap heater blanket
adapter (1) from body (e). Remove packing (2) from
(8) around shell (20) and secure in position with tape as in
adapter. Drop piston (3) and spring (5) from bore of body.
original configuration.
Remove packing (4) from groove in piston.
g. To reassembly pneumatic dump valve, position
c. Unwrap tape and remove heater blanket (8) from
lubricated packing (4) in groove around piston (3). Install
around separator she!! (20).
spring (5) and piston in body (6). Place lubricated packing
d. Remove pipe plug (9) from tank cap (13).
(2) in groove in adapter (1). Screw adapter into body and
Unscrew disc ring retainers (10) and remove disc rings
tighten until flange bottoms.
(11) and rupture discs (12) from ports in cap.
h. Test assembled pneumatic dump valve in
e. Unscrew tank cap (13) from separator shell(20).
accordance with instructions in paragraph 4.12.6. After
Slip gasket (14) from groove in cap.
completing tests, screw valve into port at bottom of
separator shell.
f. Remove screw and plug assembly(16) and washer
(17), and lift filter element (15) and gasket (18) from cap
4.12.5 FILTER AND SEPARATOR LEAKAGE TEST.
(13).
Test the filter and separator for leakage before attaching
g. Do not remove thermostat switch (19) from recess
the heater blanket or thermostat switch, or installing the
in shell (20) unless a new switch is required. Switch is
pneumatic dump valve.
pressed into shell and will be unusable if removed.
NOTE
If the thermostat switch was not
4.12.3 CLEANING AND INSPECTING PARTS. Clean
removed during disassembly, it
and inspect the parts of the disassembled pneumatic
must be protected against moisture
dump valve and filter and separator assembly as follows:
by covering with waterproof tape.
a. Wash all parts, except filter element, packings
a. Install pressure plugs in all ports except one.
and gaskets, in dry-cleaning solvent (Federal Specification
Connect variable source of compressed air to remaining
P-S-661). Dry parts thoroughly with clean, lint-free cloths
port.
and/or low-pressure compressed air.
b. Pressurize filter and separator to 3000 psig.
b. Inspect parts for scoring, pitting, wear and other
While maintaining this Internal pressure, brush a soap-
evidence of damage. Make sure all drilled passages are
water-solution on joints of assembly. Maximum allowable
unobstructed.
leakage, as evidenced by air bubbles, is one bubble per
minute.
c. Check operation of heater blanket and thermostat
switch against performance requirements listed in Table 1.
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