8-18. In  a  refrigerant  plant,  liquid refrigerant  may  flood  back  to  the compressor  from  the  evaporator  if  the thermostatic  expansion  valve  is 1. stuck shut 2. adjusted  for  too  high  superheat  at the  outlet 3. adjusted  for  too  low  superheat  at the  outlet 4. reducing  the  amount  of  refrigerant flowing  into  the  coil 8-19. If  it  is  suspected  that  the  expansion valve  assembly  requires  replacement, which of the following conditions should be  met  before  an  expansion  valve  test  is made? 1. The  liquid  strainers  are  cleaned 2. The  solenoid  valves  are  operative 3. The  system  is  sufficiently  charged 4. Each of the above 8-20. What  should   a service   drum that is used for  testing   an expans ion  valve  contain? 1. Pressurized  R-12 2. Dry  compressed  air 3. A gas similiar to the one used in the  thermal  element  of  the  valve 4. Each of the above gasses For  questions  8-21  through  8-24,  assume that  you  are  testing  the  thermostatic expansion  valve  of  a  refrigeration  plant. 8-21. When  should  the  thermal  element  be immersed in a bath of crushed ice? 1. Before  the  valve  inlet  is  attached to the gas source 2. After  the  high  and  low  pressure gages  have  been  connected 3. Before  the  high  pressure  gage  is connected  to  the  valve  outlet 4. After  the  valve  on  the  air  supply line has been opened 8-22. A  thermostatic  expansion  valve  is  set for  5°F  of  superheat,  what  should  the outlet  pressure  read  on  a  gage? 8-23. Which  of  the  following  operating conditions  is  an  indication  that  the expansion  valve  is  seating  properly? 1. Low  pressure  gage  stops  increasing after a few pounds 2. Low  pressure  gage  continues  to increase  slowly  after  a  few  pounds 3. Either 1 or 2 above happens 4. Low pressure gage increases rapidly and  equals  the  inlet  pressure 8-24. You  have  removed  the  ice  packing  from  the control bulb. Which of the following outlet  pressure  conditions  indicates  that the  valve  is  operating  normally? 1. The  pressure  does  not  change 2. The  pressure  decreases  rapidly 3. The  pressure  increases  rapidly 4. The  pressure  decreases  a  few  pounds, then  stabilizes Question 8-25 is to be judged True or False. 8-25. The  entire  expansion  valve  assembly  must be  replaced  when  the  power  element  is inoperative. Learning Objective: Recognize practices that  will  help  assure  a  properly operating  refrigeration  and  air conditioning  system,    and identify some of the  symptoms  that  may  lead  to  system failure. 8-26. Under  normal  operating  conditions  how full  should  the  receiver  of  a  properly charged  refrigeration  system  be  when  the compressor  stops? 1. 25% full 2. 50% full 3. 85% full 4. 100%  full 1. 16.1 psi 2. 22.5  psi 3. 26.1 psi 4. 32.5 psi 50