Maintenance
Turbines are designed to run for decades with very little maintenance of the main elements; overhaul intervals are on the order of several years. Maintenance of the runners and parts exposed to water include removal, inspection, and repair of worn parts.
Normal wear and tear includes pitting from cavitation, fatigue cracking, and abrasion from suspended solids in the water. Steel elements are repaired by welding, usually with stainless steel rods. Damaged areas are cut or ground out, then welded back up to their original or an improved profile. Old turbine runners may have a significant amount of stainless steel added this way by the end of their lifetime. Elaborate welding procedures may be used to achieve the highest quality repairs.
Other elements requiring inspection and repair during overhauls include bearings, packing box and shaft sleeves, servomotors, cooling systems for the bearings and generator coils, seal rings, wicket gate linkage elements and all surfaces.
Read more about this topic: Water Turbine
Famous quotes containing the word maintenance:
“In public buildings set aside for the care and maintenance of the goods of the middle ages, a staff of civil service art attendants praise all the dead, irrelevant scribblings and scrawlings that, at best, have only historical interest for idiots and layabouts.”
—George Grosz (1893–1959)
“However patriarchal the world, at home the child knows that his mother is the source of all power. The hand that rocks the cradle rules his world. . . . The son never forgets that he owes his life to his mother, not just the creation of it but the maintenance of it, and that he owes her a debt he cannot conceivably repay, but which she may call in at any time.”
—Frank Pittman (20th century)
“It is an injustice that an old, broken, half-dead father should enjoy alone, in a corner of his hearth, possessions that would suffice for the advancement and maintenance of many children.”
—Michel de Montaigne (1533–1592)