TM 1-4220-250-12&P 4.7 INSPECTION-ACCEPTANCE/REJECTION CRITERIA FOR SRU-37/P. 4.7.1 LRU-18/U Life Raft Function Test. This task covers:  Test Materials/Parts Initial Setup 3/8-or 1/2-Inch Diameter Rubber Tools/Equipment Hose 157E24-2201    (D15) Gloves (D25) Equipment Conditions Vacuum Cleaner 791-00-807-3704 (or Shop Air Vac)                                  Life Raft Removed From Container Assembly 1. Functional Test.  To functionally test the LRU-18/U life raft assembly,  proceed as follows: CAUTION For life raft inflation,  ensure that there is adequate area free of foreign objects. NOTE A   functional   test   shall   be   performed every   third   120   ±    10   day   inspection period. Functional tests will be accomplished with the cylinder attached to the life raft.  Cylinder and valves will remain  with  the  same  life  raft  until  the life    raft    is    functionally    tested,        or inspection    reveals    the    cylinder    and valve  to  be  unserviceable.    This  is  to ensure    that    the    cylinder    and    valve assembly is checked for proper function. a. Open  life  raft  container  assembly,    unfold  life raft,  and lay it flat. b. Measure time of inflation; life raft shall inflate to design  shape  without  evidence  of  restriction  in less than 30 seconds. c. Actuate inflation assembly. d. If   raft   does   not   properly   inflate,      determine cause.  (See Table 4-2.) e. Examine  life  raft  for  obvious  defects  such  as cuts, tears, and ruptured seams. WARNING To prevent burns,  personnel removing C0₂ cylinders should wear gloves (D25). f. If  no  obvious  defects  are  found,    remove  the C0₂ inflation valve assembly. g. Ensure that the check valve assembly is clean, free  from  foreign  matter  and  not  damaged.    If check  valve  assembly  is  damaged,    replace  in accordance with paragraph 4.8.5. h. Repair  inflation  valve  assembly  in  accordance with paragraph 4.8.4. i. If   repairs   are   made,      recheck   in   accordance with steps b and c. j. Deflate life raft.  Ensure that all carbon dioxide has been removed. 2. DEFLATION.      To   deflate   the   LRU-18/U   life   raft, proceed as follows: a. Attach one end of rubber hose (D15) to vacuum source. b. Unlock  applicable  oral  inflation  valve,    hold  in open  position,    and  hold  vacuum  pump  hose against  end  of  inflation  valve.    When  cell  is collapsed,      release   oral   inflation   valve   and screw lock closed. NOTE The vacuum source hose should be held at an angle to the inflation valve or air will not properly evacuate the cell. END OF TASK 4-11