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