Gasket Leakage on Y-Strainer Bolted Flange

Problem

Flange gasket leaked on a Y-Strainer at a steam plant for a local university. Leakage occurred on this piping system so maintenance replaced the full face gasket and the leak persisted. They then changed gasket material with no success. Joint sealant was also tried and it immediately failed. Design Pressure is 175 psig, Temp. 375 deg. F. Service media is steam. 10 inch flange.

Solution

The flanges were inspected and found to be in acceptable condition with minimal gouges and imperfections. AP Services reps also verified the torque values and proper installation procedures were followed. During this investigation, it was found that the studs being used have never been changed since the plant went online and were an inferior grade which did not allow for proper torque. New bolts were installed and upgraded to B7, hardened flat washer was used under the flange nuts, and the bolting system was lubricated. AP Services also upgraded the material to flexible graphite sheet to help take care of any cuts/gouges in flange. The application has been leak-free since.

Product Info

AP STYLE 6300R