To install a manhole or handhole plate, first center the fitting in the opening. Make sure the shoulder does not bind on the edges of the opening. Then slip the yoke on and start the stud nut. Run the nut on the stud until it is  hand  tight;  then  give  the  nut  one-quarter  of  a  turn with  a  wrench.  Do  NOT  tighten  the  nut  enough  to compress the gasket. When  the  boiler  is  given  a  hydrostatic  test,  the pressure of the water usually forces the manhole and handhole  gaskets  into  place  and  thus  ensures  proper seating.  The  plates  are  first  set  up  lightly.  When  the boiler  is  ready  for  testing,  the  pressure  should  be pumped  up  to  within  50  psi  of  the  hydrostatic  test pressure, regardless of any leakage from the manhole or handhole plates. Leakage is likely to be general at first, but it decreases as the pressure is increased. When the pressure is within 50 psi of the test pressure, most of the leakage stops although the nuts are still loose. If  some  plates  are  leaking  badly,  the  trouble  is probably caused by improper seating of the gaskets. As a rule, the gasket is caught on the outer edge between the edge of the plate and the edge of the counterbore for the seat. A light blow with a hammer on the outside of the plate usually relieves the tension on the gasket and allows  it  to  seat  properly. After leaky gaskets have been adjusted and while full test pressure is on the boiler, tighten up all plates firmly.  Use  only  the  wrenches  specified  for  this purpose. Some  economizer  headers  and  a  few  superheater headers  are  fitted  with  handhole  plugs  instead  of handhole  plates.  Also,  some  economizers  have bayonet types of cleanout plugs on the front ends of the tube  loops  to  allow  access  to  the  tubes  at  the  return bend  end.  Detailed  instructions  for  installing  and removing  the  plug  type  of  manhole  fittings  and  the return  bend  cleanout  fittings  are  given  in  appropriate manufacturer’s  technical  manuals. HYDROSTATIC  TESTS The  boiler  should  be  given  a  hydrostatic  test annually  or  whenever  the  operator  doubts  the  boiler strength.   The   purpose   of   the   test   is   to   prove   the TIGHTNESS  of  all  the  parts  of  the  boiler  or  the STRENGTH of the boiler and its parts. In preparing the boiler for a test, rinse it out with fresh water. Then check carefully to see that no loose scale or tools are left in any part of the boiler. The procedures for making boiler hydrostatic tests are as follows: 1. 2. 3. 4. 5. 6. 7. 8. Close all openings and "gag" (clamp down) all safety valves. Gags should be only hand tight and straight. Do NOT use a wrench; it will bend the  valve  stem  and  possibly  damage  the  seat. Remember  that  valves  are  easily  damaged  if lifted by water pressure. Close all connections on  the  boiler  except  air  cocks,  test  pressure gauge,  and  valves  of  the  line  through  which pressure is to be applied. Reduce the water level in the boiler by opening an air cock, and blow down the boiler until the water  level  is  below  the  feedwater  inlet connection.  Clear  the  blowdown  area  before blowdown. Connect a hydrostatic pump between the boiler and  water  service  connection.  Install  all  pipe and fittings between the pump and the boiler. Remember, the pipe and fittings must be able to withstand test pressures. Install a hose between the pump and the chosen water service. Ensure the chosen water service supplies ample water pressure to conduct the test. Remove the plug from the feedwater inlet cross by turning it in a counterclockwise direction. Open the boiler casing access doors or plates, so tube ends can be inspected during the test. Install a wedge between the control switch and the pressure-actuating platform. Also, install a stop valve before the control switch to protect the  control,  so  hydrostatic  pressure  will  not actuate or damage the control. The range of the pressure  control  is  usually  less  than  the hydrostatic  pressure  being  applied.  Do  NOT bend or damage the actuating parts. Fill the boiler with water until water discharges out  of  the  air  cock;  then  close  the  air  cock. Ensure  all  the  air  is  expelled  from  the  boiler before closing the air cock. Turn on the water service valve. The water temperature should be the  same  as  the  surrounding  atmosphere.  The minimum water temperature must be 70°F. Check the boiler steam pressure gauge in-line cock   to   ensure   that   it   is   open.   Ensure   the butterfly  handle  is  in-line  (parallel)  with  the tubing. 2-6