STEAM- JACKETED KETTLES Kettles require, as a minimum, monthly inspections. Figure   7-4   illustrates   an   arrangement   of   shipboard steam-jacketed   kettles.   An   annual   preventive maintenance  inspection  is  also  important.  Here  are  a few   factors   to   keep   in   mind   while   inspecting steam-jacketed kettles. When making a MONTHLY inspection, check the draw-off  faucets,  valves,  and  piping  for  leaks.  Check the steam pressure-reducing valve to ensure it is in good condition  and  is  functioning  properly.  Lubricate  the hinges of the kettle cover with mineral oil. During the ANNUAL inspection, check each kettle for leaks, cracks, and dents. Examine the cover, hinges, and  latch  for  warp  and  alignment.  Check  the  steam piping and the condensate piping, the valves, and the traps  for  leaks  and  obstructions.  Remove  the  safety valves; then clean, lubricate, and calibrate them before reinstalling.  Remove  any  rust  and  corrosion  by  using Navy approved solvents. Other than visual inspections, each individual piece of galley equipment requires its own type of preventive maintenance. During  each  ship’s  regularly  scheduled  overhaul, steam-jacketed   kettles   should   be   tested   using   the following procedure: 1.   Put each kettle into a cold-water pressure test of 90 psi for not less than 30 minutes. 2.  Check  the  safety  valves  on  each  kettle.  The testing of safety valves should he covered by the PMS. In  general,  kettle  safety  valves  are  set  to  release  at  a pressure of 45 psig. 3.   Replace kettles that are cracked, badly pitted, or bulge under a pressure test. 4. Replace all malfunctioning safety valves. Table 7-3 shows some common troubles and repair recommendations  on  steam-jacketed  kettles  and  other steam-heated equipment. Table 7-3.—Common Troubles and Repair Recommendations on Steam-Jacketed Kettles and Other Steam-heated Equipment Inspection   Point Steam jacket Steam jacket Steam jacket Pipe  joints Pipe  joints Control  valves Control valves Condensate  strainer Steam  trap Lagging Reducing   valve Safety  valve Covers Drawoff valve Symptoms Not  beating Stays  hot Leaks Leaks Corrosion Stuck open or closed Leaks  at  stem No flow Malfunctioning Broken or crushed Incorrect   pressure Stuck  open  or  lifting under  pressure Tight  operation Leaks Time When noted When  noted Monthly Monthly Monthly When  noted Weekly When  noted Every  6  months Quarterly When  noted When  noted When  noted When  noted Possible   Troubles/Causes No  steam;  valve  stuck closed;  trap  malfunctioning Valve partly open or scored seat Rapid  changes  in  temperature causing  cracks;  faulty  weld Joints  made  incorrectly;  not tight Leaks  or  condensation No steam or too much steam; packing too tight or valve frozen Packing  not  tight  enough Restricted   strainer Parts dirty or worn Water  soaked;  stepped  on Parts dirty or worn Leaks  or  corrosion Hinges dirty Scored Possible   Corrections Check steam supply; free stuck  valve Repair  or  replace  valve Raise heat slower, reweld bust  or  crack Unscrew,  clean  and  repair joint Repair  and/or  clean Loosen  packing  gland  or  free frozen  valve  stem Tighten packing Clean  strainer Disassemble, clean, and repair Replace  defective  sections Disassemble, clean, and repair;  clean  and  adjust pressure  every  6  months Replace or repair valve Clean  and  lubricate  binges Resurface or replace. DO NOT REPLACE WITH REGULAR  GATE  VALVE 7-7