22-12 Change A U.S. Navy Diving Manual—Volume 5 22-5 OPERATION 22-5.1 Predive Checklist.  To ensure each item is operational and ready for use, perform the  equipment  checks  listed  in  the  Recompression  Chamber  Predive  Checklist, Figure 22-11a. 22-5.2 Safety Precautions.   Do not use oil on any oxygen fitting, air fitting, or piece of equipment.   Do not allow oxygen supply tanks to be depleted below 100 psig.   Ensure dogs are in good operating condition and seals are tight.   Do not leave doors dogged (if applicable) after pressurization.   Do not allow open flames, smoking materials, or any flammables to be carried into the chamber. Table 22-2.  Recompression Chamber Air Supply Requirements. Recompression Chamber Configuration Primary Air Requirement Secondary Air Requirement CATEGORY A: No BIBS overboard dump No CO 2 scrubber No air BIBS No O 2 and CO 2 monitor Sufficient air to press the IL once and the OL twice to 165 fsw and vent during one TT6A for one tender and two patients with maximum extensions. Sufficient air to press the IL and OL once to 165 fsw and vent for one hour at 70.4 scfm. CATEGORY B: BIBS overboard dump No CO 2^scrubber No air BIBS ^O2 and CO 2 monitors Sufficient air to press the IL once and the OL twice to 165 fsw and vent for CO 2 during one TT6A for one tender and two patients with maximum extensions. Sufficient air to press the IL and OL once to 165 fsw and vent for one hour at 70.4 scfm CATEGORY C: BIBS overboard dump ^CO2 scrubber No air BIBS ^O2 and CO 2 monitors Sufficient air to press the IL once and the OL twice to 165 fsw.' Sufficient air to press the IL and OL once to 165 fsw and vent for one hour at 70.4 scfm CATEGORY D: BIBS overboard dump ^CO2 scrubber Air BIBS ^O2 and CO 2 monitor Sufficient air to press the IL once and the OL twice to 165 fsw. (For TRCS, sufficient air to power CO 2 scrubbers must be included) Sufficient air to press the IL and OL once to 165 fsw and enough air for one tender and two patients (when not on O 2 ) to breathe air BIBS during one TT6A with maximum extensions. CATEGORY E: BIBS overboard dump ^CO2 scrubber ^O2 and CO 2^monitor Spare CO 2^scrubber Secondary power supply NITROX BIBS No Air BIBS Sufficient air to press the IL once and the OL twice to 165 fsw. Sufficient air to press the IL and OL once to 165 fsw and enough air/ NITROX for one tender and two patients (when not on ^O2 ) to breathe air/NITROX BIBS during one TT6A with maximum extensions. Notes: 1) Additional air source per PSOB will be requied for TT4, 7 or 8. 2) For chambers used to conduct Sur “D” sufficient air is required to conduct a TT6A in addition to any planned Sur “D”