Assignment   10 Auxiliary  Machinery  (continued) Textbook Assignment: Engineman 1&C, NAVEDTRA 10543-E1, pages 7-22 through 8-21 Learning Objective: point out the operational, troubleshooting, and repairing  techniques  for  the submerged tube and the flash-type distilling  plants. 10-1. 10-2. 10-3. 10-4. Which of the following ships have vapor compression  distilling  units? 1. Aircraft   carriers 2. Submarines 3. Destroyers 4. Frigates Questions 10-2 through 10-21 refer to low-pressure submerged tube distilling plants. Varied operating conditions are a primary cause of which of the following problems? 1. Changes  in  feed  levels 2. Scaling  of  evaporator  tubes 3. Improper  liquid  level  in  the  first effect 4. Higher  steam  pressures You need to adjust three controls in order to bring heat and fluid condition into balance. You  should  use  which  of the  following  techniques? 1. Adjust  all  three  controls simultaneously 2. Adjust all three controls singly and quickly 3. Adjust each control singly and in increments 4. Adjust  each  control  at  lo-minute intervals Which of the following factors is/are most likely to cause a decrease in the plant's   efficiency? 1. Air leaks in the first tube nest 2. Low  volume  in  the  last-effect  shell 3. Dirty  circulating  water  strainer 4. All of the above 10-5. 10-6. 10-7. 10-8. 10-9. Steam orifices should be inspected how often? 1. Monthly 2. Biannually 3. Annually 4. With each overhaul Water used to desuperheat live steam should  be  taken  from  what  source? 1. The first-effect tube nest drain pump 2. The second-effect tube nest drain pump 3. The freshwater supply 4. The steam feed system Fluctuations in the first-effect steam pressure and temperature cause similar fluctuations  in  which  of  the  following parts  of  the  plant? 1. The  second  effect  only 2. The  steam  supply  line  only 3. The water levels only 4. The  entire  plant Tubes in the first-effect tube nest should be cleaned whenever the mercury drops below which of the following levels? 1. 1 in. 2. 1 1/2 in. 3. 2 in. 4. 2 1/2 in. When you can NOT feed water into the first  effect,  you  should  look  for  which of  the  following  causes? 1. Scale  deposits  in  the  air  ejector condenser 2. Scale  deposits  in  the  vapor feed  heater 3. Obstructions  in  the  feed  line 4. All of the above 61