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23 Cards in this Set
- Front
- Back
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What does CRP do? |
Controllable reversible pitch Varies angle of prop blades (pitch) so we do not have to change the rotation of the shaft. Shafts always rotate in the outward direction. |
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What has to happen with the CRP system is secured? |
Once every four hours, the IEM is to log the head tank level and report level If no oil is sighted, then the CCS supervisor is to start the pump and fill the head tank. |
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What is the range of the prop blades? |
-61% to 120% |
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What are the CRP sump levels? |
1300 full; 1100 operating |
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What are the CRP head tank levels? |
150-190 capacity 125 - 150 operating |
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What are the CRP electric pumps logics? |
Starts at <90 gpm flow Shuts off at >120 gpm flow |
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What is the CRP electric pump rated at? |
190 gpm for 1000 psi |
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How many microns is are the quad filters? |
25 microns |
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What are the control oil filters rated at ? |
25 micron |
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What are the pump suction duplex filters rated at? |
238 microns |
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What does the sequencing valve open up at? |
Opens @ 500 psi |
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What does the aux reducing valve reduce CRP pressure to? |
Reduces 500 psi to 400 psi |
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What pressure does the main relief valve open at? |
Lifts at 1000 psi |
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What does the aux relief valve do? |
Protects control oil side Lifts at 500 psi |
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What does the hopm bypass valve do? |
Relieves power oil back to sump during initial startup to prevent over pressurization of the hub |
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What is the CRP path? |
Sump > suction check valve > strainers > pumps > quad filters > ball check valve |
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Path for control oil? |
Aux reducing valve > control oil filter > changeover valves > ehsv if in auto, joystick if in manual > aux servo piston to control movement of valve rod |
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Power oil path? |
Sequencing valve (500 psi to open to ensure pressure is sent to aux reducing valve first) > aux servo piston to control movement of valve rod > main servo piston to move blades at hub > return to sump of control oil > return to sump/ head tank if power oil |
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What is the purpose of the CRP head tank? |
Maintains static head pressure on the oil in the hub when the system is secured, stopping seawater from leaking past the blades into the system. |
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What does the OD box do? |
Each shaft has an od box mounted on the forward end of the gear casing and it’s purpose is to control the position of the blades. Local control of pitch from inside the main space |
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What is the hopm? |
Hydraulic oil power module Divides CRP into two types of oil power and control oil |
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What is the nstm for CRP? |
245 |
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What is emergency ahead pitch? |
Set in the event of a CRP hydraulic failure, when the operational necessity exists to operate the shaft Hand operated pump is connected to the OD box. Used to pump the aux piston to the 120% position. Locking mechanism used once set. |
