4.7.2 LRU-18/U Leakage Teat (Continued).
Measuring device ON/OFF valve must be
closed when air feed valve is open.
Refer to Table 4-3 for quick reference of life
raft test pressures. Both cells may be tested
If a suitable air source is not available,
water-pumped nitrogen (D13) may be
Unlock oral inflation valve of CO2 cell and
insert into 1/2-inch diameter rubber hose.
Close measuring device ON/OFF valve and
open valve to air supply and inflate life raft.
Alternately position valves at measuring
device and air supply until proper pressure of
2.0 psi is attained. Repeat procedure for oral
cell, but inflate to 1.0 psi.
The air supply shall be securely shut off. After
a minimum of 15 minutes, the pressure shall
be readjusted in both cells to the original
pressures called out in Table 4-3.
Disconnect air supply and check test Future
for leaks. Ensure that all valves are closed.
Six hours after the readjustment period, the
pressure shall be measured and corrections for
changes in temperature made. For each lo F
rise or drop in temperature, 0.031 (31/1000)
psig shall be subtracted from or added to the
final pressure reading to obtain the corrected
pressure. For 0-10°F change see Table 4-4.
Table 4-3. LRU-18/U Test Pressures.
If the life raft has been stacked during the
6-hour inspection period, remove from
stacking and place in a horizontal position on
the floor or table in the inspection area and
take test pressure reading. In no event shall
the pressure in the raft be determined with
another raft stacked upon it.
If corrected pressure in CO2 cell is below 1.6
psi or corrected pressure in oral cell is below
0.6 psi, inflate to leakage test pressure and coat
with a soap solution to locate leaks. Mark leak
areas. Rinse life raft with fresh water, air dry,
and repair IAW paragraph 4.8.1.
Steps g through i shall be performed only after
leakage test readings have been recorded.
Deflate raft in accordance with paragraph 4.7.1.
Ensure that inflation valve lever is cocked.
Install new CO2 cylinder in accordance with
Table 4-4. Temperature Conversion Chart.
Rise in temperature: subtract from gauge reading.
Fall in temperature: add to gauge reading.
END OF TASK