TM 10-6640-239-13 4-116 4-50.    GAS CYLINDER AND GAS REGULATOR VALVE. This task consists of: a. Remove b. Install INITIAL SET-UP Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 1) General Safety Instructions WARNING Pressure systems safety precautions apply to all ranges of pressure.  Care must be take during testing to ensure that all test connections are properly and tightly made prior to applying pressure to the test setup.  Ensure gas cylinder valves are tightly closed prior to removing/replacing gas cylinders.  Use care in moving gas cylinders. REMOVE Remove Gas Cylinder (Typical).  See Figure 4-44. a. Open gas cylinder cabinet door. b. Unlatch appropriate gas cylinder sliding rack retaining lock (1). c. Pull gas cylinder sliding rack (2) out from cabinet. d. Close gas cylinder discharge valve (3). e. Disconnect and remove gas regulator (4) from gas cylinder (5) and replace protective cap (6). f. Release upper and lower retaining straps (7) that secure gas cylinder (5) to sliding rack (2). g. Remove gas cylinder (5). INSTALL Install Gas Cylinder (Typical).  See Figure 4-44. a. Install gas cylinder (5) in position on sliding rack (2) and secure with upper and lower retaining straps (7). b. Remove protective caps (6) and install gas regulator (4) on gas cylinder (5). c. Open gas cylinder discharge valve (3). d. Slide cylinder sliding rack (2) with cylinder (5) into storage position in cabinet taking care not to kink hoses. e. Latch gas cylinder sliding rack retaining lock (1). f. Verify proper operation. g. Close gas cylinder cabinet door.