A client from a Nuclear Power Station contacted us to see if we could offer a Remanufacture Plus solution for a highly stressed valve seat in the boiler HP Bypass System. Their usual supplier had closed and they were seeking improved life from the component.
Following a full assessment of a failed component to determine all dimensions and materials it was shown that the original design had used Stellite® hard facing material, which is prone to cracking (see our <IP intercept case study> for a good example of this problem).
A proposal was determined and put to our customer, who agreed to the upgrade.
This included the use of an advanced Cobalt alloy to form the seat, fully welded to the parent material.
The proposal included qualification of the weld procedure (WPQR) for the advanced Cobalt alloy in accordance with standards EN ISO 14732: 2013.
This includes laboratory micrographic and mechanical tests, dye penetrant NDT, macro examination, macro photograph and hardness survey across the weld and Heat Affected Zone (HAZ).
– XRF analysis of an original component to determine materials used.
– Co-ordinate measuring machine to determine all dimensions.
– Engineering and Technical review to determine the required course of action.
– Determine then Qualify the WPQR needed.