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3 Cards in this Set
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- Back
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Describe the procedure for getting a boiler ready for survey |
1. A suitable time needs to be arranged, taking into consideration steam demand and standby arrangements before the boiler is laid up. 2. Any standby boiler should be fully tested, including safety devices, to ensure a problem free operation, before the boiler is shutdown. 3. Tools, spares and manpower should all be confirmed before the job begins. 4. A work plan needs to be created for the isolation, referring to any company and/or OEM procedures. 5. Thorough risk assessment needs to be carried out, with a permit to work, full lockout and ragout completed as per work plan. 6. Economisers should be cross connected, and normal operation confirmed, including pressures and temperatures before the boiler is shut down. 7. Once the standby boiler is up and running and everything okay, the boiler can be shut down. 8. The boiler should be locked and tagged out, including combustion circuit (fuel, steam etc.) 9. The ECR and watch keeper should at all times be kept up to date, and made aware that the boiler is no longer available for use. 10. Contingency plan should be made in the event that the running boiler cannot maintain steam pressure. 11. With the boiler isolated, including feed inlets, economiser returns and steam stop valves, the boiler should be left to cool down naturally, to avoid thermal stressing of the components. 12. Double isolations should be used wherever possible, and if not possible, then blanks fitted in order to allow for the inspection of the shell valves. 13. The boiler should be left to drop in pressure until around 1 bar. At this point the vent line should be cracked open and steam witnessed out of the line. Check the vent line clear and prove the pressure inside. 14. Boiler can now be slowly, fully emptied, with the vent line fully open such that no vacuum is pulled inside. 15. The top door should be opened first, just cracked open to ensure no vacuum condition exists inside. BE CAREFUL, STILL ROASTING. 16. With the top door open, and when its safe and cool to do so, the water side can be checked for its magnetite layer, this is like a gunmetal, purpley colour however this will soon disappear when oxygen is allowed in. 17. Boiler is an enclosed space and for any entry it requires an enclosed space permit to work. 18. Furnace can be inspected, for any oil sludge build up, any erosion around the tube plate and tubes, flame impingement, refractory. 19. All Shell valves should be removed, clearly marked, checked for any scale formation, corrosion or erosion, and overhauled. 20. once survey completed, boiler should be put back to normal, loaded up as per OEM. |
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What are the lifting and seating pressures regarding boiler safety valves?
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The safety valve will lift at a maximum of 3% above design pressure. The valve should prevent an accumulation of pressure of no more than 10% above design pressure. The valve should seat at no more than 10% below design pressure. |
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What are the following made out of? ship hull, superstructure,bedplate,liner,cyl cover,piston, crankshaft |
Ship Hull- 0.23% Carbon Steel Superstructure- Aluminium Bedplate- 0.4% medium carbon steel Cylinder liner- grey cast iron alloy Cylinder cover- forged steel (2 stroke) Cast iron (4stroke) Piston- crown molybdenum steel crankshaft- 0.4% carbon steel main bearings- white metal, tin aluminium on a steel shell |
