CAUTION Do not heat the tank in excess of 110°F to seal the injection groove as higher temperatures are considered as a fire hazard. The proper temperatures for sealing are 79° to 84°F. If the tank is exposed to temperatures below 50°F, the tank  must  be  heated  above  70°F  before  sealing  is attempted. This may be accomplished in a heated hangar or by using portable heating units or electric blankets. NOTE:  If  the  sealing  compound  does  not appear  after  approximately  4  to  5  minutes,  you may assume that the compound is too cold, the groove   is   plugged,   or   the   surface   gap   is excessive. In this case, the injection should be discontinued  until  the  discrepancy  is  remedied. Testing When an integral fuel cell has been repaired, it must be  pressure  checked  before  it  is  filled  with  fuel.  Since the pressure testing procedure will vary with different types  of  aircraft,  you  should  always  consult  the structural repair manual for the aircraft concerned for the proper procedure. The following equipment is used for  pressure  testing  as  system: ·    A source of nitrogen and a means of regulating the nitrogen pressure NOTE: The use of nitrogen for pressure testing the fuel system is recommended since nitrogen is  an  inert  gas,  and  therefore  presents  no explosive  hazard  when  it  is  introduced  into  a fuel cell containing fuel vapors. A source of dry air  is  not  recommended  because  it  would increase the ratio of oxygen to fuel vapor in the cell,  and  the  possibility  of  an  explosion  would be  increased. · · · Suitable hoses and fittings to connect the testing equipment  to  fuel  the  system A0 to 5 psi pressure gauge installed downstream of the nitrogen supply Miscellaneous  plugs  and  caps  for  blocking various lines and fittings RECOMMENDED  READING  LIST NOTE: Although the following references were current  when  this  TRAMAN  was  published,  their continued  currency  cannot  be  assured.  Therefore,  you need to be sure that you are studying the latest revision. Blueprint   Reading   and   Sketching,   NAVEDTRA 10077-F1, Naval Education and Training Program Management Support Activity, Pensacola, Florida, July 1988. Fluid Power,  NAVEDTRA  12964,  Naval  Education  and Training  Program  Management  Support  Activity, Pensacola,  Florida,  July  1990. Naval Aviation Maintenance Program, OPNAVINST 4790.2  (series),  Office  of  the  Chief  of  Naval Operations,  Washington,  D.C. Aviation  Hydraulics  Manual,   NAVAIR   01-1A-17, Commander,  Naval  Air  Systems  Command, Washington, D. C., 1 February 1992. General  Manual  for  Structural  Repair,   NAVAIR 01-1A-1,   Commander,   Naval   Air   Systems Command,  Washington,  D.  C.,  15  July  1969, Change 11, 15 August 1989. Technical  Manual  Structural  Hardware,  NAVAIR 01-1A-8,   Commander,   Naval   Air   Systems Command, Washington, D. C., 1 September 1980, Change 24, 15 October 1987. Naval  Occupation  Safety  and  Health  (NAVOSH) Program  Manual  For  Forces  Afloat  OPNAVINST 5100.19A,   Commander,   Naval   Air   Systems Command, Washington, D. C., January 1983. Naval  Occupational  Safety  and  Health  (NAVOSH) Program   Manual,   OPNAVINST    5100.23B, Commander,  Naval  Air  Systems  Command, Washington,  D.  C.,  August  1988. Navy  Support  Equipment  Common  Basic  Handling  and Safety  Manual  NAVAIR  00-80T-96,  Commander, Naval Air Systems Command, Washington, D. C., 1 April 81, Change 1, March 1986. Technical Manual Index and Application Tables for Aircraft Jacks, NAVAIR 19-70-46, Commander, Naval Air Systems Command, Washington, D. C., 1 November  1989. Technical  Manual  USN  Aircraft  Weight  and  Balance Control, NAVAIR 01-1B-50, Commander, Naval Air  Systems  Command,  Washington,  D.  C.,  1 October 1990. 3-50