TM 10-6640-215-13 5-18.  REMOVE/INSTALL ELECTRIC STEAM BOILER SIGHT GLASS. This task consists of: a.  Removal b.  Installation INITIAL SET-UP: Tools required General Mechanics Tool Kit, (Appendix B, Section III, Item 2) REMOVAL Remove Electric Steam Boiler Sight Glass.  See Figure 5-16. WARNING To   prevent   injury   to   personnel,   be   sure   electric   steam   boiler   has   had   time   to   cool   before performing  any  maintenance.    Steam  temperature  as  high  as  600°F  (279.9°C)  can  be  obtained  in this unit. a. Close two isolation valves. b. Lift two protective rods from sight glass. c. Loosen two retaining nuts and remove sight glass. INSTALLATION Install Electric Steam Boiler Sight Glass.  See Figure 5-16. WARNING To   prevent   injury   to   personnel,   be   sure   electric   steam   boiler   has   had   time   to   cool   before performing  any  maintenance.    Steam  temperature  as  high  as  600°F  (279.9°C)  can  be  obtained  in this unit. a. Position sight glass between two retaining nuts.  Tighten nuts. b. Slide two protective rods down through holes in isolation valves. c. Open two isolation valves. 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. 5-32