TM 10-6640-215-13 4-53. REMOVE/INSTALL GAS CYLINDERS AND GAS REGULATOR VALVES - continued. c. Pull gas cylinder sliding rack out from cabinet. d. Close gas cylinder discharge valve. e. Disconnect and remove gas regulator from gas cylinder and replace protective cap. f. Release the upper and lower retaining straps that secure gas cylinder to sliding rack. g. Remove gas cylinder. INSTALLATION Install Gas Cylinder (Typical).  See figure 4-53. a. Place gas cylinder in position on sliding rack. b. Secure gas cylinder on sliding rack with upper and lower retaining straps. c. Remove protective caps and install gas regulator on gas cylinder. d. Slide cylinder sliding rack with cylinder into storage position in cabinet taking care not to kink hoses. e. Latch the gas cylinder sliding rack retaining lock. f. Verify gas regulator operation. g. Close gas cylinder cabinet door. 4-54. REMOVE/INSTALL WATER LEVEL REGULATOR. This task covers:   a. Removal b. Installation INITIAL SETUP: Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 2) Materials/Parts Required Teflon Tape, (Appendix E, Section II, Item 157) 4-142