7. Non Destructive Test: base on rule, % welding joint need to do NDT will be choosen. For ex:
(1) Apply at least 10% of random RT to butt joint based on the class rule.
(Choose RT point upon the decision of QM)
(2) Apply 100% of random RT to stern cargo line
8. Pipe Covering / Protection
(1) After the inspection of pipe at shop and before the coating process, do the covering to the tip of the pipe based on sealing rule. This can protect the pipe from foreign substance influx.
(2) After the coating process, do the covering on the surface of the pipe. The covering should be removed after the on-board process is done.
9. Shop Sus Pipe Work Process (Flow Diagram)
10. Onboard Sus Pipe Work Process:
There are various grades and surface finishes of stainless steel to suit the environment the alloy must endure. Stainless steel is used where both the properties of steel and corrosion resistance are required.
Stainless steel differs from carbon steel by the amount of chromium present. Unprotected carbon steel rusts readily when exposed to air and moisture. This iron oxide film (the rust) is active and accelerates corrosion by making it easier for more iron oxide to form. Since iron oxide has lower density than steel, the film expands and tends to flake and fall away. In comparison, stainless steels contain sufficient chromium to undergo passivation, forming an inert film of chromium oxide on the surface. This layer prevents further corrosion by blocking oxygen diffusion to the steel surface and stops corrosion from spreading into the bulk of the metal. Passivation occurs only if the proportion of chromium is high enough and oxygen is present in it.
Stainless steel’s resistance to corrosion and staining, low maintenance, and familiar lustre make it an ideal material for many applications. The alloy is milled into coils, sheets, plates, bars, wire, and tubing to be used in cookware, cutlery, household hardware, surgical instruments, major appliances, industrial equipment (for example, in sugar refineries) and as an automotive and aerospace structural alloy and construction material in large buildings. Storage tanks and tankers used to transport orange juice and other food are often made of stainless steel, because of its corrosion resistance. This also influences its use in commercial kitchens and food processing plants, as it can be steam-cleaned and sterilized and does not need paint or other surface finishes.
Pls refer to other part: Part 1