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4
TRIM OPERATIONS
(For Vessels Having a Centrifugal Trim Pump and a Priming Pump)
 
A. PUMP FROM FORWARD TRIM TANK TO SEA WITH TRIM PUMP
 
1. Open the forward trim tank flood and suction valve on the forward trim manifold, in the forward torpedo room.

2. Open the forward trim line suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the discharge to sea valve on the trim manifold.

6. Open the trim pump sea stop valve in the control room.

7. Open the forward trim tank vent valve on the 225-pound service air manifold in the control room. (When pumping to or from a tank, the tank must be vented.)

8. Open the priming pump suction stop valve at the priming float valves

9. Open the trim manifold priming vent valve leading to the priming float valve.

10. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

11. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

  12. Shut the trim manifold priming vent valve.

13. Shut the priming pump suction stop valve. (Operations 8 to 13 inclusive may be omitted if the trim system is filled with water from previous use.)

14. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

15. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

16. Shut the trim pump suction valve on the trim manifold.

17. Shut the trim pump discharge valve on the trim manifold.

18. Shut the discharge to sea valve on the trim manifold.

19. Shut the trim pump sea stop valve.

20. Shut the forward trim line suction valve on the trim manifold.

21. Shut the forward trim tank flood and suction valve on the forward trim manifold, in the forward torpedo room.

22. Shut the forward trim tank vent valve on the 225-pound service air manifold.

 
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Figure 4-1. PUMP FROM THE FORWARD TRIM TANK TO SEA WITH THE TRIM PUMP.
 
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B. PUMP FROM AFTER TRIM TANK TO FORWARD TRIM TANK WITH TRIM PUMP
 
1. Open the after trim tank flood and suction valve on the after trim manifold, in the after torpedo room.

2. Open the after trim line suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the forward trim line discharge valve on the trim manifold.

6. Open the forward trim tank flood and suction valve on the forward trim manifold, in the forward torpedo room.

7. Open the after trim tank vent valve on the 225-pound service air manifold in the control room.

8. Open the forward trim tank vent valve on the 225-pound service air manifold. (When pumping to or from a tank, the tank must be vented.)

9. Open the priming pump suction stop valve at the priming float valve.

10. Open the trim manifold priming vent valve leading to the priming float valve.

11. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

12. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

  13. Shut the trim manifold priming vent valve.

14. Shut the priming pump suction stop valve. (Operations 9 to 14 inclusive may be omitted if the trim system is filled with water from previous use.)

15. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

16. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

17. Shut the trim pump suction valve on the trim manifold.

18. Shut the trim pump discharge valve on the trim manifold.

19. Shut the forward trim line discharge valve on the trim manifold.

20. Shut the forward trim tank flood and suction valve on the forward trim manifold in the forward torpedo room.

21. Shut the after trim line suction valve on the trim manifold.

22. Shut the after trim tank flood and suction valve on the after trim manifold, in the after torpedo room.

23. Shut the forward trim tank vent valve on the 225-pound service air manifold.

24. Shut the after trim tank valve on the 225-pound service air manifold.

 
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Figure 4-2. PUMP FROM THE AFTER TRIM TANK TO THE FORWARD TRIM TANK WITH THE TRIM PUMP
 
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C. PUMP FROM FORWARD WRT TANK TO SEA WITH TRIM PUMP
 
1. Open the forward torpedo tube drain stop valve to the WRT tank in the forward torpedo room.

2. Open the WRT tank flood and suction valve on the forward trim manifold, in the forward torpedo room.

3. Open the forward trim line suction valve on the trim manifold.

4. Open the trim pump suction valve on the trim manifold.

5. Open the trim pump discharge valve on the trim manifold.

6. Open the discharge to sea valve on the trim manifold.

7. Open the trim pump sea stop valve.

8. Open the WRT tank vent valve on the forward torpedo tube blow and vent manifold. (When pumping to or from a tank, the tank must be vented.)

9. Open the priming pump suction stop valve at the priming float valve.

10. Open the trim manifold priming vent valve leading to the priming float valve.

11. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

12. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

13. Shut the trim manifold priming vent valve.

  14. Shut the priming pump suction stop valve. (Operations 9 to 14 inclusive may be omitted if the trim system is filled with water from previous use.)

15. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

16. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

17. Shut the trim pump suction valve on the trim manifold.

18. Shut the trim pump discharge valve on the trim manifold.

19. Shut the discharge to sea valve on the trim manifold.

20. Shut the trim pump sea stop valve.

21. Shut the forward trim line suction valve on the manifold.

22. Shut the WRT tank flood and suction valve on the forward trim manifold, in the forward torpedo room.

23. Shut the forward torpedo tube drain stop valve to the WRT tank in the forward torpedo room.

24. Shut the WRT tank vent valve on the forward torpedo tube blow and vent manifold, in the forward torpedo room.

 
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Figure 4-3. PUMP FROM FORWARD WRT TANK TO SEA WITH TRIM PUMP.
 
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D. PUMP FROM AUXILIARY BALLAST TANK NO. 1 TO FORWARD TRIM TANK WITH TRIM PUMP
 
1. Open the auxiliary ballast tank No. 1 flood and suction valve in the pump room.

2. Open the auxiliary ballast tank No. 1 suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the forward trim line discharge valve on the trim manifold.

6. Open the forward trim tank flood and suction valve on the forward trim manifold in the forward torpedo room.

7. Open the auxiliary ballast tank No. 1 blow and vent stop valve at the starboard side of the crew's mess room.

8. Open the auxiliary ballast tank No. 1 vent valve on the 225-pound service air manifold in the control room.

9. Open the forward trim tank vent valve on the 225-pound service air manifold. (When pumping to or from a tank, the tank must be vented.)

10. Open the priming pump suction stop valve at the priming float valve.

11. Open the trim manifold priming vent valve leading to the priming float valve.

12. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

13. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

  14. Shut the trim manifold priming vent valve.

15. Shut the priming pump suction stop valve. (Operations 10 to 15 inclusive may be omitted if the trim system is filled with water from previous use.)

16. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

17. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

18. Shut the trim pump suction valve on the trim manifold.

19. Shut the trim pump discharge valve on the trim manifold.

20. Shut the forward trim line discharge valve on the trim manifold in the control room.

21. Shut the forward trim tank flood and suction valve on the forward trim manifold, in the forward torpedo room.

22. Shut the auxiliary ballast tank No. 1 suction valve on the trim manifold.

23. Shut the auxiliary ballast tank No. 1 flood and suction valve in the pump room.

24. Shut the forward trim tank vent valve on the 225-pound service air manifold.

25. Shut the auxiliary ballast tank No. 1 vent valve on the 225-pound service air manifold.

26. Shut the auxiliary ballast tank No. 1 blow and vent stop valve.

 
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Figure 4-4. PUMP FROM AUXILIARY BALLAST TANK NO. 1 TO FORWARD TRIM TANK WITH TRIM PUMP.
 
36

 
E. PUMP FROM SAFETY TANK TO SEA WITH TRIM PUMP
 
1. Open the safety tank flood and suction valve in the pump room. 2. Open the safety tank suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the discharge to sea valve on the trim manifold.

6. Open the trim pump sea stop valve in the control room.

7. Vent the safety tank outboard at the hydraulic vent manifold. (See note below.) (When pumping to or from a tank, the tank must be vented.)

8. Open the priming pump suction stop valve leading to the priming float valve.

9. Open the trim manifold priming vent valve leading to the priming float valve.

10. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

11. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

12. Shut the trim manifold priming vent valve.

13. Shut the priming pump suction stop valve. (Operations 8 to 13 inclusive may be omitted if the trim system is filled with water from previous use.)

  14. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

15. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

16. Shut the trim pump suction valve on the trim manifold.

17. Shut the trim pump discharge valve on the trim manifold.

18. Shut the discharge to sea valve on the trim manifold.

19. Shut the trim pump sea stop valve in the control room.

20. Shut the safety tank suction valve on the trim manifold.

21. Shut the safety tank flood and suction valve in the pump room.

22. Shut the safety tank vent at the hydraulic vent manifold.

NOTE: Since the safety tank is being vented outboard, this operation is possible only while the submarine is on the surface. If the safety tank is vented inboard, pumping may be done while submerged.

 
36

Figure 4-5. PUMP FROM SAFETY TANK TO SEA WITH TRIM PUMP.
 
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F. PUMP FROM NEGATIVE TANK TO SEA WITH TRIM PUMP
 
1. Open the negative tank flood and suction valve in the pump room.

2. Open the negative tank suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the discharge to sea valve on the trim manifold.

6. Open the trim pump sea stop valve in the control room.

7. Open the negative tank vent stop valves in the pump room. (When pumping to or from a tank, the tank must be vented. Negative tank vents inboard only.)

8. Open the negative tank vent valve at the forward port corner of the control room.

9. Open the priming pump suction stop valve at the priming float valve.

10. Open the trim manifold priming vent valve leading to the priming float valve.

11. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

12. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

  13. Shut the trim manifold priming vent valve.

14. Shut the priming pump suction stop valve. (Operations 9 to 14 inclusive may be omitted if the tram system is filled with water from previous use.)

15. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

16. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

17. Shut the trim pump suction valve on the trim manifold.

18. Shut the trim pump discharge valve on the trim manifold.

19. Shut the discharge to sea valve on the trim manifold.

20. Shut the trim pump sea stop valve in the control room.

21. Shut the negative tank suction valve on the trim manifold.

22. Shut the negative tank flood and suction valve in the pump room.

23. Shut the negative tank vent valve in the control room.

24. Shut the negative tank vent stop valves in the pump room.

 
37

Figure 4-6. PUMP FROM NEGATIVE TANK TO SEA WITH TRIM PUMP.
 
37

 
G. PUMP FROM NEGATIVE TANK TO AUXILIARY BALLAST TANK NO. 2 WITH TRIM PUMP
 
1. Open the negative tank flood and suction valve in the pump room.

2. Open the negative tank suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the auxiliary ballast tank No. 2 discharge valve on the trim manifold.

6. Open the auxiliary ballast tank No. 2 flood and suction valve in the pump room.

7. Open both negative tank vent stop valves in the pump room.

8. Open the auxiliary ballast tank No. 2 blow and vent stop valve at the port side of the crew's mess room.

9. Open the negative tank vent valve at the forward port corner of the control room.

10. Open the auxiliary ballast tank No. 2 vent valve on the 225-pound service air manifold. (When pumping to or from a tank, the tank must be vented.)

11. Open the priming pump suction stop valve at the priming float valve.

12. Open the trim manifold priming vent valve leading to the priming float valve.

13. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

14. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

15. Shut the trim manifold priming vent valve.

  16. Shut the priming pump suction stop valve. (Operations 11 to 16 inclusive may be omitted if the trim system is filled with water from previous use.)

17. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

18. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

19. Shut the trim pump suction valve on the trim manifold.

20. Shut the trim pump discharge valve on the trim manifold.

21. Shut the auxiliary ballast tank No. 2 discharge valve on the trim manifold.

22. Shut the auxiliary ballast tank No. 2 flood and suction valve in the pump room.

23. Shut the negative tank suction valve on the trim manifold.

24. Shut the negative tank flood and suction valve in the pump room.

25. Shut the negative tank vent stop valves in the pump room.

26. Shut the auxiliary ballast tank No. 2 blow and vent stop valve in the crew's mess. room.

27. Shut the auxiliary ballast tank No. 2 vent stop valve on the 225-pound service air manifold.

28. Shut the negative tank vent valve in the port corner of the control room.

 
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Figure 4-7. PUMP FROM NEGATIVE TANK TO AUXILIARY BALLAST TANK NO. 2 WITH TRIM PUMP.
 
38

 
H. PUMP FROM SEA TO HOSE CONNECTION IN FORWARD ENGINE ROOM WITH DRAIN PUMP
 
1. Remove the cap from and connect a hose to the trim line hose connection in the forward engine room.

2. Open the trim pump sea stop valve in the control room.

3. Open the sea suction valve on the trim manifold.

4. Open the after trim line discharge valve on the trim manifold.

5. Open the drain pump cross connection valve.

6. Open the drain pump suction valve.

7. Open the drain pump discharge valve to the trim manifold.

8. Open the trim line hose connection valve in the forward engine room.

9. Start the drain pump.

10. Observe the drain pump indicator lamps to determine whether the water in the drain pump air chambers is at the proper level (see Sections 3B2 and 3BS).

The water is at the proper level when only the lower light marked DRAIN PUMP LOW is ON.

  When both lights are ON, the water level is too high. Admit additional air into the air chambers by means of the 225-pound air connection to the drain pump.

When both lights are OUT, the water level is too low. Expel some air from the air chambers by means of the vent valve on the drain pump.

11. Stop the drain pump when water is no longer required at the hose.

12. Shut the sea suction valve on the trim manifold.

13. Shut the trim pump sea stop valve in the control room.

14. Shut the trim line hose connection valve.

15. Remove the hose from the trim line hose connection and replace the cap.

16. Shut the drain pump discharge valve to the trim manifold.

17. Shut the drain pump suction valve.

18. Shut the drain pump cross connection valve.

19. Shut the after trim line discharge valve on the trim manifold.

 
39

Figure 4-8. PUMP FROM SEA TO HOSE CONNECTION IN FORWARD ENGINE ROOM WITH DRAIN PUMP.
 
39

 
I. PUMP FROM NO. 1 TO NO. 2 AUXILIARY BALLAST TANK WITH TRIM PUMP
 
1. Open the auxiliary ballast tank No. 1 flood and suction valve in the pump room.

2. Open the auxiliary ballast tank No. 1 suction valve on the trim manifold in the control room.

3. Open the trim pump suction valve on the trim manifold.

4. Open the trim pump discharge valve on the trim manifold.

5. Open the auxiliary ballast tank No. 2 discharge valve on the trim manifold.

6. Open the auxiliary ballast tank No. 2 flood and suction valve in the pump room.

7. Open the auxiliary ballast tank No. 1 blow and vent stop valve at the starboard side of the crew's mess room.

8. Open the auxiliary ballast tank No. 2 blow and vent stop valve at the port side of the crew's mess room.

9. Open the auxiliary ballast tank No. 1 vent valve on the 225-pound service air manifold.

10. Open the auxiliary ballast tank No. 2 vent valve on the 225-pound service air manifold. (When pumping to or from a tank, the tank must be vented.)

11. Open the priming pump suction stop valve at the priming float valve.

12. Open the trim manifold priming vent valve leading to the priming float valve.

13. Start the priming pump. Observe the priming pump vacuum gage. If the gage reads below about 20 inches, the trim pump is not fully primed since this vacuum reading indicates the float valve is not filled with water. (The sealing water tank gage must register at least two-thirds full for effective operation of the priming pump.)

14. Stop the priming pump when the gage reads about 20 inches, indicating high vacuum.

15. Shut the trim manifold priming vent valve.

  16. Shut the priming pump suction stop valve. (Operations 11 to 16 inclusive may be omitted if the trim system is filled with water from previous use.)

17. Turn the trim pump control rheostat to the slowest speed position. Start and operate the trim pump. Adjust speed to obtain desired rate of pumping. (Effective pumping is indicated by air flow which can be felt when holding the hand over the vent on the 225-pound service air manifold and a discharge reading of the trim meter which measures flow in pounds. If there is no flow, repeat priming operation.)

18. Stop the trim pump when the trim meter indicates that the required weight of water has been discharged.

19. Shut the trim pump suction valve on the trim manifold.

20. Shut the trim pump discharge valve on the trim manifold.

21. Shut the auxiliary ballast tank No. 2 discharge valve on the trim manifold.

22. Shut the auxiliary ballast tank No. 1 suction valve on the trim manifold.

23. Shut the auxiliary ballast tank No. 2 flood and suction valve in the pump room.

24. Shut the auxiliary ballast tank No. 1 flood and suction valve in the pump room.

25. Shut the auxiliary ballast tank No. 2 vent valve on the 225-pound service air manifold.

26. Shut the auxiliary ballast tank No.1 vent valve on the 225-pound service air manifold. 27. Shut the auxiliary ballast tank No. 2 blow and vent stop valve on the port side of the crew's mess room.

28. Shut the auxiliary ballast tank No. 1 blow and vent stop valve on the starboard side of the crew's mess room.

 
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Figure 4-9. PUMP FROM NO. 1 TO NO. 2 AUXILIARY BALLAST TANK WITH TRIM PUMP.
 
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