We have recently had an incident in a turbine generator where an earth fault caused excessive damage to the stator and rotor. Melted copper was deposited on the outer surface of the 18Cr-18Mn coil retaining ring. Copper melts at 1085degC. I would expect that as the copper cooled, excessive...
What is the effect of hydrotesting a steel vessel to pressures ranging from 1,2 to 1,35 times the design pressure in terms of approaching or exceeding the yield strength? Can limited yielding be expected? If a vessel has been hydrotested to 1,35x design pressure at commissioning and then...
Thanks for the responses Metalguy. We have performed an extensive refurbishment programme on about 4000m of 304L piping - we surface buffed ALL the pipe and inspected with liquid dye penetrant. ALL defects (pits, cracks, scratches etc) were then removed by deeper buffing (while respecting...
We dose the system with crystalline boric acid - it is the nuclear safeguard system of a Pressurised Water Reactor. The 304L has suffered severe transgranular SCC deradation on the external surface and our concern is that it will be especially susceptible to any form of impurity or oxygen...
We are using backing rings in 304L piping where it is difficult to obtain a satisfactory purge. The service fluid is borated water at 25 deg Centigrade. The piping has proven to be extremely susceptible to SCC from external chloride contamination and high residual tensile stresses. Therefore...
