- Engine should have run 30 mins of diesel oil before stoppage
- Open the indicator cocks, shut the main air starting valve and engage the turning gear
- close the fuel supply and ruturn valve on the fuel pump
- Drain the remaining fuel from the fuel pump
- Inspect the cams and rollers
- The stagnation pressure control valve has to be dismantled
- Note the valve desiganation S-suction , D- delivery and U- for spill valve
- Remove the valve cover and the springs
- Pressure bushes are released using special wrench
- The vavles are removed using a withdrawal device
- Examine valve seats and contact surfaces. Defective should be reconditioned or replaced
- The valve contact surface in fuel pump block should be in good condition.Damaged surfaces must be reconditioned
- After cleaning the fuel pump block throughly the suction and spill valves are cleaned in diesel oils and fitted back respectively without their springs
- The pressure bushes are tightened to 300Nm
- The dial gauges should be inspected before mounting it to their holes
- Start the oil pump for bearings and crossheads and adjust pressure to normal operation
- set reversing lever on emergency control stant to ahead
- The fuel lever is removed from remote position and engaged to position " 8 "
- The shutdown servo motor is set to its working position
- The piston of the shutdown servomotor is locked in position by means of spacing tube and tensioning bolts
- The control air shut off valves are closed and then system is vented
- The fuel quality setting lever is to Zero . Note its position befor mixing
- Replace the VIT cam with a circular running in disc
- Set the fuel lever on the emergency control stand. So that the pointer on adjusting scale is on 8. Specified on the accepatance record
- Make sure the VIT indicator is at 0(zero) and the roller is in contact with the circular disc and no spaces are there to reduce the fuel delivery
1. High cost: Manganese bronze is a costly alloy, making it less economical for large propellers. 2. Low strength-to-weight ratio: Compared to other propeller materials like nickel-aluminum bronze or stainless steel, manganese bronze has a lower strength-to-weight ratio. 3. Susceptible to corrosion: Manganese bronze can corrode in seawater, especially when exposed to high velocities and turbulence. 4. Poor cavitation resistance: Manganese bronze is more prone to cavitation damage than other materials. 5. Difficult to cast and machine: Manganese bronze is challenging to cast and machine, making it less desirable for complex propeller geometries. 6. Limited weldability: Manganese bronze has poor weldability, making repairs and modifications difficult. Nickel-aluminum bronze or stainless steel are commonly used for propellers due to their: - High strength and durability - Excellent corrosion resistance - Good cavitation resistance - Ease of casting and machining - Weldability
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