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PREVENTATIVE MAINTENANCE

TM-5-3895-374-24-2 M081 Asphalt Mixing Plant Manual
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TM 5-3895-374-24-2 2. Check alignment - See suggestions under "Installation Alignment" in this manual. 3. Check  piping  to  be  sure  there   is   no   strain   on   the pump casing. 4. Rotate  the  pump  shaft  by  hand  to  be  sure  it  turns freely. 5. Jog motor to be sure it is turning in the right direction: see discussion on pump rotation under "Installation - General" item 4 in this manual. 6. Check   any   pressure   relief   valve   to   be   sure   it   is installed correctly.  See discussion on pressure relief valve under "Installation - General". 7. Check suction piping to be sure (a) it is all connected and tight, (b) valves are open, and (c) end of pipe is below liquid level. 8. Check discharge piping to be sure (a) it is connected and tight, (b) valves are open, and (c) there is a place for the liquid to go. 9. Lubricate   any   grease   fitting   on   the   pump   using   a good,    general    purpose    #2    ball    bearing    grease. Check  any  gear  reducer,  motor,  coupling,  etc.    for instructions   and   lubricate   as   recommended.      See Engineering Service Bulletin ESB515. 10. or   packed   pumps,   loosen   packing   gland   nuts   so gland can be moved slightly by hand. Adjust gland to reduce leakage only after pump has run long enough   to   reach   constant   temperature.      Packing should weep a little to keep it cool and lubricated. 11. Do not use the Viking pump to flush, pressure test or prove the system with water.  Either remove the pump or   run   piping   around   it   while   flushing   or   testing. Pumping   water,   dirty   or   otherwise,   can   do   more damage   in   a   few   minutes   than   months   of   normal service. 12. Check to be sure all guards are in place. 13. Now you are ready to push the "start" button - gently. If the pump begins to deliver liquid within 60 seconds, you’re in business.  If it does not, push the "stop" button.  Do not run the pump longer than one minute without liquid in it; you will ruin it. Review the steps just outlined, consider what the suction and discharge gauges indicate, see page 6:  if everything appears to be in order, put some liquid in the pump, a lubricating liquid is best.  This will help it prime. Push  the  "start"  button  again.    If  nothing  is  flowing  within  two minutes.  stop the pump.  The pump is not a compressor, it will not  build  up  much  air  pressure:    it  may  be  necessary  to  vent the discharge line until liquid begins to flow. If  the  pump  still  does  not  deliver,  the  cause  may  be  one  or more of the following: 1. Suction line air leaks; vacuum  gauge  reading  should help determine if this is the problem. 2. End  of  suction  pipe  not  submerged  deep  enough  in liquid. 3. Suction  lift  is  too  great  or  the  suction  piping  is  too small. 4. Liquid is vaporizing in the suction line before it gets to the pump. If  after  consideration  of  these  points  it  still  does  not  pump, suggest  you  review  again  all  points  given  under  START  UP; read through Troubleshooting in this manual and try again.  If it still does not pump, contact your Viking representative. TROUBLESHOOTING A Viking pump which  is  properly  installed  and  maintained  will give long and satisfactory performance. NOTE Before  making  any  pump  adjustment  or opening  the  pump  liquid  chamber  in  any manner, make sure that: 1)  any  pressure  in  the  pumping  chamber  has  been  vented through   the   suction   or   discharge   lines   or   other   openings provided for this purpose, 2) the driver has  been  "locked  out" so  that  it  cannot  inadvertently  be  started  while  work  is  being done on the pump and 3) the pump has been allowed to cool down  to  the  point  where  there  is  no  chance  of  anyone  being burned. If  trouble  does  develop,  one  of  the  first  steps  toward  finding the  difficulty  is  to  install  a  vacuum  gauge  in  the  suction  port and  a  pressure  gauge  in  the  discharge  port.    Readings  on these gauges often will give a clue as to where to start looking for the trouble. Vacuum Gauge - Suction Port 1. High reading would indicate a. Suction  line  blocked  -  foot  valve  stuck,  gate valve closed, strainer plugged. b. Liquid too viscous to flow through the piping. c. Lift too high. d. Line too small. 2. Low reading would indicate a. Air leak in suction line. b. End of pipe not in liquid. c. Pump is worn. d. Pump is dry - should be primed. 3. Fluttering, jumping, or erratic reading a. Liquid vaporizing. b. Liquid coming to pump in slugs, possibly an air leak or insufficient liquid above the  end  of  the suction pipe. c. Vibrating    from    cavitation,    misalignment,    or damaged parts. Pressure Gauge - Discharge Port 1. High reading would indicate a. High viscosity and small and/or long discharge line. b. Gate valve partially closed. c. Filter plugged. d. Vertical  head  did  not  consider  a  high  specific gravity liquid. e. Line  partially  plugged  from  build  up  on  inside of pipe. f. Liquid in pipe not up to temperature. g. Liquid    in    pipe    has    undergone    a    chemical reaction and has solidified. h. Relief valve set too high. 2. Low reading would indicate a. Relief valve set too low. Page 3 - 1206







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