MD&A Webinars | Managing Emergent Findings during Overhaul: "Diaphragm Dishing Issues"
The Diaphragm Dishing presentation will cover types of diaphragm construction, causes of diaphragm dishing, signs of dishing, and give examples of diaphragm failures. Repair options with photos are shown including structural repairs with weld replacement and the addition of bridges. New manufacture and nozzle plates are also included.
Customer takeaways from the session:
A) Dishing is the permanent downstream deflection of a diaphragm due to high temperature creep.
B) Insufficient main weld depth, weak weld material, inadequate partition cross-section, a lack of bridges, running overtemperature and poor weld quality can all contribute to diaphragm dishing.
C) Opening axial clearances to the diaphragm webs and HiLo packing teeth should be reviewed early in an outage for signs of diaphragm dishing.
D) Structural dishing repairs during an outage can include increasing weld depth and adding bridges to correct the original design/manufacturing deficiencies.