TM  10-4930-204-23P Section I. INTRODUCTION 1.  Scope.  This   manual   lists   spares   and   repair parts; special tools; special test, measurement, and diagnostic  equipment  (TMDE),  and  other  special support   equipment   required   for   performance   of organizational,   direct   support,   and   general   sup- port  maintenance  of  the  Tank  and  Pump  Unit.  It authorizes  the  requisitioning  and  issue  of  spares and  repair  parts  as  indicated  by  the  source  and maintenance codes. 2.  General.  This  Repair  Parts  and  Special  Tools List is divided into the following sections: a. Section II. Repair Parts List. A list of spares and  repair  parts  authorized  for  use  in  the  per- formance  of  maintenance.  The  list  also  includes parts  which  must  be  removed  for  replacement  of the  authorized  parts.  Parts  lists  are  composed  of functional  groups  in  numeric  sequence,  with  the parts  in  each  group  listed  in  figure  and  item number   sequence.   Bulk   materials   are   listed   in NSN sequence. b.  Section  III.  Special  Tools  List.  A  list  of special  tools,  special  TMDE,  and  other  special support equipment authorized for the performance of maintenance. c. Section IV. National Stock Number and Part Number Index.  A list, in National item identifica- tion number (NIIN) sequence, of all National stock numbers (NSN) appearing in the listings, followed by   a   list   in   alphameric   sequence,   of   all   part numbers  appearing  in  the  listings.  National  stock numbers and part numbers are cross-referenced to each   illustration   figure   and   item   number   ap- pearance.  This  index  is  followed  by  a  cross- reference list of reference designators to figure and item numbers. 3. Explanation of Columns. a.  Illustration.   This   column   is   divided   as follows: (1)  Figure  Number. Indicates   the   figure number  of  the  illustration  on  which  the  item  is shown. (2) Item Number. The number used to identify item called out in the illustration. b.  Source,  Maintenance  and  Recoverability (SMR) Codes. (1)  Source  Code.  Source  codes  indicate  the manner   of   acquiring support items   for maintenance,  repair  or  overhaul  of  end  items. Source  codes  are  entered  in  the  first  and  second positions  of  the  Uniform  SMR  Code  format  as follows: Code PA PB PC PD PE PF PG KD KF Definition Item   procured a n d    s t o c k e d    f or anticipated or known usage. Item procured and stocked for insurance purposes   because   essentiality   dictates that a minimum quantity be available in the  supply  system. Item  procured  and  stocked  and  which otherwise  would  be  coded  PA  except that it is deteriorative in nature. Support   item, excluding   support equipment,  procured  for  initial  issue  or outfitting   and   stocked   only   for   subse- quent or additional initial issues or out- fitting. Not   subject   to   automatic replenishment. Support   equipment   procured   and stocked  for  initial  issue  or  outfitting  to specified  maintenance  repair  activities. Support   equipment   which   will   not   be stocked  but  which  will  be  centrally  pro- cured on demand. Item   procured   and   stocked   to   provide for  sustained  support  for  the  life  of  the equipment.   It   is   applied   to   an   item peculiar   to   the   equipment   which, because   of   probable   discontinuance   or shutdown  of  production  facilities,  would prove   uneconomical   to   reproduce   at   a later  time. An  item  of  a  depot  overhaul/repair  kit and  not  purchased  separately.  Depot  kit defined  as  a  kit  that  provides  items  re- quired at the time of overhaul or repair. An  item  of  a  maintenance  kit  and  not purchased   separately.   Maintenance   kit defined  as  a  kit  that  provides  an  item that can be replaced at organizational or intermediate levels of maintenance. 1