Sunrod boiler inspection and cleaning

1.Open furnace and confirm that the furnace drain pipe is clear.

   Wash furnace tubes and sunrod elements with HPWJ.(high pressure water jet)
   Confirm that water drains from the furnace instantly otherwise
   tubes will be corroded due to sulphuric acid attack.

2.HPWJ is not enough to clean the Sunrod elements.
   Clean sunrod elements gas side from top & bottom by constructing special
    tools.Confirm that the pins of the elements are clean.
   This is not an easy job and have to check many times that the pins
   are clean

3.Open steam drum and all the inspection doors of the water header.

4.Raise the angle bar on the top of the furnace pipe.
Flush with high pressure water one by one all the furnace tubes and confirm that
water is draining to the water header.
Replace angle bar in position confirming that all hinges are intact.

5.Confirm that all the connections of water low level shut down float switch
and water level transmitters are clear and overhaul all the small valves

6.Overhaul all the blowdown valves

7.Inspect condition of refractories inside the furnace and renew as necessary

8.Check furnace air tightness and repair accordingly.

Comments

Manganese bronze is not typically used as a propeller material .Why

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

MAN B&W MC Engine VIT Pump

The pump is basically a jerk type with a plunger moving in a matched barrel, using two helical grooves machined in the plunger to control the end of injection by uncovering spill ports and causing the discharge pressure to drop rapidly, thus causing the needle valve in the injector to close. Oil is supplied to the barrel via the spill ports and a suction valve. The suction valve, situated at the top of the barrel opens when the pressure in the barrel falls below the supply pump pressure; i.e. during downward stroke of plunger, while spill ports are covered by plunger. Replaceable erosion plugs are fitted in the pump housing opposite the spill ports. The high pressure oil, spilling back, as the edge of the helix uncovers the s...

Shell Expansion Plan

It is a two dimensional drawing of a three dimensional surface of the ship’s hull form. This plan is very useful for the following information:It is used for marking the location of a hull Damage on this plan by identifying the strake number , letter and frame number so that the exact location of the damage and also suggested repairs are marked in a localised copy. The shell expansion can be used for finding areas of painting surfaces such as topside, boot topping and bottom areas by applying Simpsons rules directly. In the shell expansion the vertical scale used is different from the horizontal scale and a suitable adjustment has to be made when calculating areas. This becomes useful in solving disputes concerning areas of preparation and painting. It gives information on the thickness of the original strake which is indicated by the number in the circle shown in the strake. The quality of steel used is also shown by letters A,B,D E and AH, BH,DH, EH.

MEOclassIIexamnotes

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