TM   10-6640-216-13&P D-During Table 2-11. Operator Preventive Maintenance Checks and Services - continued B - Before A - After M - Monthly W - Weekly Interval Procedures Item Check for and have Equipment is Item to Be repaired or adjusted Not Ready/ No. B D A W M    Inspected as necessary. Available If: 2 Recessed Inspect  for  condition Steps  damaged  or Step and  security. loose. Assemblies 3 Laboratory Inspect for broken or Defective  or  missing Tiedown missing  rings. rings. Rings 4 Blower a.  Check  louvers  for Louvers  are  blocked. Exhaust any  obstructions. Door b.  Inspect  access  door Latches,   keepers, for  defective  or seals,  or  hinges missing  latches, damaged  or  missing. keepers,  seals,  and hinges. 5 Purge Port a. Inspect  access  doors Latches,  keepers, Doors for  defective  or seals,  or  hinges missing  latches, damaged  or  missing. keepers,  seals,  and hinges. b.  Inspect  door  micro- Microswitches  do  not switches to be sure operate   correctly. they  activate properly when door is closed,  and deactivated  when door is opened. c.  Check  air  exhaust Dirty,  damaged  or filters  for  cleanliness, missing  exhaust damage  or  missing filters. condition. 6 Utilities Box a. Inspect  access  door Latches,  keepers, and Access for  defective  or seal,  or  hinges Door missing  latches, damaged  or  missing. keepers, seal, and hinge. b.  Check  connectors  for Defective  or  loose security  and connections. damaged  threads. 2-23