TM 10-6640-215-13 5-7.  REMOVE/INSTALL WATER TANK DRAIN. This task consists of a.  Removal b.  Installation INITIAL SET-UP: Tools required General Mechanics Tool Kit, (Appendix B, Section III, Item 2) Material Required Teflon Tape, (Appendix E, Section II, Item 157) Equipment Condition Water tank removed (para 5-6). REMOVAL Remove Water Tank Drain.  See figure 5-3. a. Disconnect drain valve and attached pipe fittings from water tank. b. Disconnect pipe fitting and tee from drain valve. INSTALLATION Install Water Tank Drain.  See figure 5-3. a. Apply teflon tape to male pipe fittings.  Be sure to wrap tape in same direction as pipe thread. b Connect tee and pipe fitting to drain valve. c. Connect drain valve and attached fittings to water tank. d. Install water tank (para 5-6). e. Prepare and operate water system using internal water tank as source in accordance with procedures listed in paragraph 2-8. f.   Inspect for leaks and check for proper operation. Figure 5-3.  Water Tank Drain Removal and Installation 5-6