TM 10-8415-208-12 Table 3-2.  Unit Preventive Maintenance Checks and Services for the STEPO-I (Cont) A - After Operation Q - Quarterly INTERVAL Item Item To Be Procedures Equipment Is No. Inspected Check For And Have Repaired Not Ready/ A Q Or Adjusted As Necessary Available If: 20 · Disconnect face piece vent Coupling is tube coupling. connected. 21 · ·    Vent Tube Ensure plugs are installed in Plugs missing. Plugs vent tube ends. 22 Metal Tubing Inspect for damage and Damage is found or tightness of connections. connections are loose. 23 · Waist and Inspect webbing for rips or Webbing is ripped or Chest Straps tears and broken buckles. torn or buckles broken. 24 Face Piece Inspect for cuts, holes or any Cuts, holes or other damage. damage is found. 25 · Ensure lens is clean. Dirty lens. 26 · Clean, disinfect and sanitize Unit not clean. (See paragraph 3-9.4) 27 · Head Harness Inspect for missing or broken Buckles are broken Straps buckles.  Ensure proper fit. or missing.  Proper fit cannot be made by minor adjustments. 28 Breathing Inspect breathing tube for Damage is found or Tube damage and ensure the cover cover not tied on. is tied at both ends. 29 Disconnect breathing tube from Breathing tube is regulator. attached. 30 Face Piece Ensure warning light lamp is Lamp not installed. Light installed. 31 Warning Light Disconnect face piece electrical Cable is connected. Cable connector NOTE The filter cartridge will be replaced after each use or every 6 months for a unit in storage. 32 Filter Ensure filter has been installed in Filter missing. filter housing. Change 2  3-138