TM   5-4930-227-14 Section XIV. TANKS AND COMPONENTS 3-41. Cleaning Tanks and Components b. Draining Tank. a.  General.  The  tank  and  tank  components must be cleaned before any repair is initiated. Each  time  a  major  component  is  removed  for  re- pair, inspection or other service, all parts must be thoroughly cleaned. Clean the discharge valve each time the tank is drained. Clean the tank in- terior  and  exterior  prior  to  repair. b.  Components.  Clean  metal  parts  with  clean- ing solvent, Federal Specification P-S-661. Im- merse  each  part  in  solvent  and  remove  contami- nants  by  brushing.  Allow  parts  to  dry  thorough- ly.  Coat  parts  with  a  thin  film  of  light  lubri- cating  oil  or  perservative  oil  before  assembly. 3-42. Manhole Assembly a. Vent Assembly. The manhole assembly ((7) fig.  3-32)  is  provided  with  a  vent  assembly located in the cover (6). b.  Removal. (1)  Refer  to  figure  3-33,  release  cam  (7) and raise hing (15). (2)  Open  manhole  cover  (10)  and  loosen the six nuts (2) so that, hooks (4) will drop free of tank rim. (3)  Lift  manhole  cover  from  tank. c. Disassembly.  Refer to figure 3–33 and dis- assemble  manhole  cover. d.  Cleaning  and  Inspection. (1) Clean parts with an approved cleaning solvent  and  dry  thoroughly. (2)  Impact  parts  for  breaks,  cracks,  dam- aged  threads  and  defects.  Replace  a  defective part. e. Reassembly. Refer to figure 3-33 and reas- semble  the  manhole  cover. f.  Installation. (1) Replace manhole cover on tank. (2)  Position  hooks  (4)  on  tank  rim  and tighten nuts (2), (3)  Close  cover  (10),  drop  hinge  (15)  into position  and  lock  cam  (7). 3-43. Pump Port a. General. A pump port cover assembly ( (10 fig. 3-32) is provided so that a hand pump may be used. b. Service.  Remove pump port cover and ex- amine gasket. Replace if defective. 3-44. Drain Valve Assembly a. General.  A drain valve assembly is provided for  draining  the  tanks. (1)  Refer  to  figure  3-32  and  turn  handle (9)  counterclockwise  to  drain  tank. (2)  Turn  handle  clockwise  to  close  drain. c.  Removal. (1)  Remove  manhole  cover  (para  342). (2)  Insure  that  tank  has  been  completely drained. (3)  Enter  tank  through  manhole  opening. (4)  Refer  to  figure  3-34  and  loosen  set- screw (5). d. Disassembly. Refer to figure 3-34 and dis- assemble  drain  valve. e.  Cleaning  and  Inspection. (1) Clean  all  parts  with  an  approved  clean- ing solvent and dry thoroughly. (2)  Inspect  all  parts  for  breaks,  cracks, and  damaged  threads.  Replace  a  damaged  part. f. Reassembly.  Refer to figure 3-34 and reas- semble  drain  valve. g.  Installation. (1) Tighten setscrew (5). (2) Replace manhole cover (para 342). 3-45. Discharge Valve Assembly a.  Removal. (1)  Remove  manhole  cover  (para  3-42). (2)   Pull   control   lever   ((5)   fig.   3-32)   to close position and remove dust cap (17). (3)  Enter  tank  thru  manhole  opening. (4)  Refer  to  figure  3-35,  loosen  adjusting bale  (6),  disengage  lift  rod  (7)  from  adjusting bale and remove lift rod. (5)   Outside   the   tank,   remove   six   nuts (24) holding valve to sump ring (8) and remove valve  assembly. b. Disassembly. Refer to figure 3-35 and dis- assemble  valve. c. Cleaning  and  Inspection. (1) Clean  all  parts  with  an  approved  clean- ing solvent and dry thoroughly. (2) Inspect all parts for cracks, breaks, or other  damage.  Replace  a  defective  part. d.  Reassembly.  Refer  to  figure  3–35  and  reas- semble  discharge  valve. e. Installation. (1) Position valve body (20) cm sump ring (8) and install nuts (24). (2)  Inside  tank,  place  lift  rod  (7)  in  stem (12) ancl adjusting bale (6), and tighten adjust- ing  bale. (3) Replace manhole cover (para 3-42). 3-40