TM 10-6640-215-13 5-21.  REMOVE/INSTALL FLOW CONTROL DEVICES (GUM BATH SYSTEM). This task consists of: a.  Removal b.  Installation INITIAL SET-UP: Tools required General Mechanics Tool Kit, (Appendix B, Section II1, Item 2) Material Required Teflon Tape, (Appendix E, Section II, Item 157) References TB-SIG-222, Soldering Methods and Techniques REMOVAL Remove Gum Bath System Flow Control Devices.  See Figure 5-20. a. Remove threaded flow control devices by unscrewing device from tees or elbows located in system piping. b. To remove soldered/brazed valves or flow control devices, proceed as follows: (1) Disconnect pipe union(s) closest to control device to being removed. (2) Remove pipe section with control device attached. (3) Unsolder/unbraze control device from piping. INSTALLATION Install Gum Bath System Flow Control Devices.  See Figure 5-20. a. Apply teflon tape to male fittings.  Be sure to wrap tape in same direction as pipe thread. b. Screw threaded flow control devices into tees or elbows located in system piping. c. To install soldered/brazed valves or flow control devices, proceed as follows: (1) Solder/braze control device to piping. (2) Install pipe section with control device attached. (3) Connect pipe union(s). d. Prepare and operate water system using internal water tank as source in accordance with procedures listed in paragraph 2-8. e. Inspect for leaks and check for proper operation. 5-40