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Flared Fittings
PACKING  AND  GASKET MATERIAL

Fireman - Navy Firefighter, Fireman training manual
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service  systems  at  a  maximum  operating  pressure of 3000 psi and a maximum operating temperature of   250°F.   Flareless   fittings   are   installed   to conserve space and to reduce weight, installation time,  and  system  cleaning  time.  Do  not  use flareless fittings if you do not have enough space to  properly  tighten  the  nuts  or  if  you  have  to remove the equipment or piping for access to the fittings. An exception to this rule is a gauge board. It is designed so it may be removed as a unit for repairs  or  alterations.  Do  not  use  flareless  fittings where  you  cannot  easily  deflect  the  piping  to permit  assembly  and  disassembly. Before  assembly,  ensure  the  tubing  end  is square,  concentric,  and  free  of  burrs.  For  an effective  fitting,  be  sure  the  cutting  edge  of  the sleeve  or  ferrule  bites  into  the  periphery  of  the tube;  you  can  do  this  by  presetting  the  ferrule. FLANGE  SAFETY  SHIELDS A  fuel  fire  in  the  MER  or  an  AMR  can  be caused by a leak at a fuel oil or lube oil pipe flange connection. Even the smallest leak can spray fine droplets of oil on nearby hot surfaces. To reduce this possibility, FLANGE SAFETY SHIELDS are provided  around  piping  flanges  of  inflammable liquid systems, especially in areas where the fire hazard  is  apparent.  The  spray  shields  are  usually made  of  aluminized  glass  cloth  and  are  simply wrapped  and  wired  around  the  flange. PIPE HANGERS Pipe hangers and supports are designed and located  to  support  the  combined  weight  of  the piping,  fluid,  and  insulation.  They  absorb  the movements imposed by thermal expansion of the pipe  and  the  motion  of  the  ship.  The  pipe  hangers and  supports  prevent  excessive  vibration  of  the piping  and  resilient  mounts  or  other  materials. They are used in the hanger arrangement to break all  metal-to-metal  contact  to  lessen  unwanted sound transmissions. One type of pipe hanger you need to become familiar with is the variable spring hanger. This is used to support the ship’s bleed air piping. It provides  support  by  directly  compressing  a  spring or springs. The loads carried by the hangers are equalized by adjustment of the hangers when they are hot. These hangers have load scales attached to them with a traveling arm or pointer that moves in a slot alongside the scale. This shows the degree of pipe movement from cold to hot. The cold and hot positions are marked on the load scale. You should  check  the  hangers  when  they  are  hot  to ensure  that  the  pointers  line  up  with  the  hot position  on  the  load  scales.  You  can  adjust hangers that are out of position by loosening the jam  nut  on  the  hanger  rod  and  turning  the adjusting  bolt  of  the  hanger. INSPECTIONS  AND  MAINTENANCE Reasonable care must be given to the various piping assemblies as well as to the units connected to the piping systems. Unless the piping system is  in  good  condition,  the  connected  units  of machinery cannot operate efficiently and safely. You should be familiar with all the recommended maintenance  procedures  and  observe  the  safety precautions  when  working  on  piping  systems. The  most  important  factor  in  maintaining piping  systems  in  satisfactory  condition  is  keeping joints,  valves,  and  fittings  tight.  To  ensure  this condition,  you  need  to  make  frequent  tests  and inspections. Piping should be tested at the frequency and test  pressure  specified  following  the  PMS  and  the applicable   equipment   technical   manual.   Test pressure  must  be  maintained  long  enough  to  show any  leaks  or  other  defects  in  the  system. Instruction manuals should be available and followed  for  the  inspection  and  maintenance  of piping  systems  and  associated  equipment;  how- ever, if the manufacturer’s instruction manual is not  available,  you  should  refer  to  the  NSTM, chapter 505, for details of piping inspection and maintenance. PIPING SYSTEM IDENTIFICATION   MARKING All piping should be marked to show the name of the service, destination (where possible), and direction  of  flow  (fig.  9-60). Figure 9-60.—Pipe markings. 9-40






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