required for the particular test you are making. A hand boiler test pump can be used in building up  the  hydrostatic  test  pressure.  If  you  do  not have a hand test pump, buildup the required test pressure  by  continuing  to  run  the  feed  pump  after the  boiler  has  been  filled.  In  any  case,  be  very careful that you do not exceed the specified test pressure.  After  the  boiler  is  full,  it  takes  very little  additional  pumping  to  build  up  pressure. To  avoid  complications  arising  from  changes in pressure caused by changes in temperature, you should use water that is approximately the same temperature as the boiler and the fireroom. In any case, the temperature of the water must be at least 70°F. While the hydrostatic pressure is being built up,  the  boiler  should  be  very  carefully  checked for signs of strain or deformation. If there is any indication  of  permanent  deformation,  stop  the hydrostatic test and make the necessary repairs. If it is not possible to make the repairs right away, give a second hydrostatic test, progressing slowly up to 20 psi less than the pressure at which the first  test  was  stopped.  If  the  boiler  passes  this second  test  successfully,  the  new  working  pressure of  the  boiler  must  be  two-thirds  of  the  test pressure  reached  on  the  second  test,  and  all  safety valves  must  be  set  accordingly. Do not make any attempt to set up on leaky handhole  or  manhole  plates  until  the  pressure  has been  pumped  up  to  within  50  psi  of  the  test pressure.  After  all  manhole  and  handhole  leakage has been remedied, pump the pressure on up to test  pressure.  Check  the  pressure  drop  over  a period of time. If all valves have been baked off, the  maximum  acceptable  pressure  drop  is  1.5% of  the  test  pressure  over  a  period  of  4  hours.  If connected  valves  are  merely  closed  and  left installed,  a  drop  test  will  not  indicate  the  true condition of the boiler. The pressure drop test is conducted  at  boiler  design  pressure. A  tube  seat  should  not  be  considered  tight unless it is bone dry at the test pressure. Any tube that cannot be made tight under a hydrostatic test should  be  renewed  or  rerolled. If  there  is  an  excessive  pressure  drop  when there  is  only  a  slight  leakage  at  tube  joints, handholes, and manholes, the loss of pressure is almost  certainly  caused  by  leakage  through  valves and   fittings.   Valves   and   fittings   should   be overhauled  and  made  tight. Five-Year Inspection and Test At  5-year  intervals,  each  boiler  must  be inspected   for   integrity   of   welds   and   nozzle connections.  Lagging  must  be  removed  from drums  and  headers  sufficiently  to  expose  the welded  joints  and  the  nozzle  connections.  The welds and nozzle connections must be inspected visually from both inside and outside. If there is any  doubt  about  the  welds,  they  should  be inspected by magnetic particle inspection or dye penetrant  inspection.  If  any  area,  through  ex- amination  (visual,  magnetic  particle,  or  dye penetrant) reveals that a 150-percent boiler design pressure  hydrostatic  test  is  warranted,  and  the  area proves  to  be  tight  under  test  pressure,  further investigation  of  the  suspected  area  should  be conducted.   The   investigation   should   continue until the true condition of the area is known, and if  necessary,  appropriate  repairs  are  made. INSPECTION OF FIRESIDES Boiler firesides should be inspected for signs of damage to the refractory lining, tubes, protec- tion plates, baffles, seal plates, support plates, and other   metal   parts.   This   type   of   inspection   is usually conducted when the boiler is secured for fireside cleaning, but it should be conducted each time  the  boiler  is  secured. Refractory Inspection Frequent  inspection  of  refractories,  together with early repair of any weak or damaged places, can do a lot to prevent refractory failure and to postpone  the  need  for  complete  renewal.  It  is  a good maintenance practice to inspect the refrac- tories  every  time  the  boiler  is  opened  up.  Such inspections  should  be  very  detailed  if  you  have reason to think the boiler has been operated under severe  service  conditions—steaming  at  high  rates, burning   low-grade   or   contaminated   fuel,   or undergoing  rapid  fluctuations  of  temperature. Severe  conditions  cause  rapid  deterioration  of refractories and, therefore, increase the need for frequent  inspections. To make a proper inspection of boiler refrac- tories,  you  should  have  considerable  knowledge of  the  causes  of  refractory  deterioration.  Also, you  should  know  how  to  tell  the  difference between  serious  damage,  which  may  require  a complete renewal of brickwork, and less serious damage,  which  may  be  dealt  with  by  patching. 12-14