3-55. You are reassembling a vital component  which  uses  a  copper sealing  ring  and  discover  there is not a new replacement ring. Which,    if any, of the following steps should you take? 1. Reinstall  the  old  ring  after inspecting it for damage 2. Install an O-ring that is compatible  with  the  fluid used  in  the  system 3. Reinstall  the  old  ring  after it has been annealed 4. None of the above 3-56. Although it has many of the characteristics  required  in  an effective seal , which of the following materials is not used as  packing  material  in  a  system in which petroleum-base fluid is used? 1. Cork 2. Asbestos 3. Natural  rubber 4. Synthetic  rubber 3-59. 3-60. 3-61. 3-62. Learning  Objective: Recognize functions, identification procedures,  inspection  and installation  techniques,  and characteristics  of  various  types of seals. 3-63. 3-57.  Which  of  the  following  statements is NOT true of T-seals? 1. T-seals  provide  a  positive seal at low pressure 2. There  is  no  military  standard part  numbering  system  to identify  T-seals 3. The dash (-) numbers used to identify the size of T-seals are part of a preliminary numbering  system 4. The Navy has created a numbering  system  to  identify T-seals  for  hydraulic actuators 3-50. To obtain the correct squeeze or clearance on V-ring packing, shims or spacers are used to adjust the packing gland depth. 1. True 2. False 3-64. Regardless  of  its  condition,  an O-ring must be discarded if it cannot  be  positively  identified. 1. True 2. False Which of the following items can be  used  to  identify  replacement O-rings? 1. Allowance parts lists (APLs) 2. Technical  manuals 3. System  drawings 4. All of the above What is the basis for computing the age of an O-ring’? 1. Service  life 2. The cure date 3. Replacement  schedule 4. Operational   conditions What is the expiration date of an O-ring which was cured on 13 July 1990 and has a 4-year shelf life? 1. 30 September 1994 2. 31 August 1994 3. 31 July 1994 4. 13 July 1994 Which  of  the  following  materials should NOT be used to fabricate tools for use in removing and installing  O-ring  and  backup rings? 1. Wood 2. Steel 3. Brass 4. Phenolic  rod Why  are  O-rings  sometimes  rolled on a cone or dowel? 1. To  expose  the  manufacturer’s identification  code 2. To expose and stretch the inner diameter surface for inspection 3. To  determine  their  breaking point 4. To condition them before installation 22