TM 9-2320-361-10 Key 11 12 Item and Function Exhaust Stack Cap is closed to force exhaust gases to enter heating chamber under tank. Shutoff Valve is opened to release exhaust gases from heating chamber. Key Item and Function 13 Manhole Covers provide openings for cleaning each compartment. 14 Filler Covers provide openings for filling each compartment. 2-13 2.5 BODY EQUIPMENT CONTROLS AND INDICATORS (Contd)