07:47 Jul-02-2001 Asim Niazi NDT Inspector Inspection Unit, Fauji Fertilizer Co., Pakistan, Joined Jul 2001 6
High Temperature UT
Q. Is it possible to flaw size a crack inside turbine casing TAPER portion ? Material Chrom-Moly steel at 150 degrees celsius. UT was performed with high temperature miniature probe 45, 60 degrees. Main crack depth was detected but crack ends could not be monitored as travelling in the raduius of taper portions of flange.
08:51 Jul-04-2001 Asim Niazi NDT Inspector Inspection Unit, Fauji Fertilizer Co., Pakistan, Joined Jul 2001 6
Re: High Temperature UT on KS Turbine Casing crack. We have experienced cracks in our Synthesis machine steam inlet nozzles which are low alloy casting. We are monitoring the depth of the cracks by using Krautkramer Gmbh probes (W45B2GV & W60B2GV) only in the straight portion due to the constructional constraints of the probes. These probes were procured to acquire data on intricate and small radius surfaces at elevated temperature service. But installation of large dimension wedges (to avoid the exposure of probe crystal to high temperature) is restricting the utilization practically for straight surfaces only. Subsequently ends monitoring cannot be ensured due to the crack propagation in nozzle curvature at one side and variable thickness portion on other side.
Can anyone please advice us regarding any other high temperature miniature angle probe or alternate non-destructive technique, which can be used to monitor the cracks depth as well as the length.