Previous explanation can be read on Boiler Tube Research (Super-Heater) Part 1.

Pipeline number 2 the condition can be seen in Figure 2.2. Visual inspection is performed to detect the location of damage to the pipe. The result can be seen in Figure 2.3 to 2.6.






From the visual inspection, conclusions may be drawn as follows:
1.Found the depletion of the outer wall pipe likely caused by erosion.
2.Found any moderately thick crust is strong enough and adhere to the outside of a pipe not subjected to erosion.
3.Did not find any excessive safety deposit on the inside of the pipe.
4.Not invent the ravages of corrosion, on the inside of pipes as, pitting corrosion, caustic corrosion or other kind of corrosion which seriously make damage .
5.Not found the depletion part of wall pipe in damage and no proof pipe beginning from the pipe


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Pipe number #2 is a segment from the pipes in secondary super-heater area. Super-heater functional is increasing saturated steam temperature from a drum into more hot steam called steam super-heat by using hot gas from furnace combustion results. Super-heater divided into two, namely primary and secondary super-heater



Primary super-heater serves to raise a saturated steam temperature from a drum into steam super-heat by earn the hot gases from furnace combustion. Primary super-heater inlet temperature is 304C and outlet temperature is 414C.


Secondary super-heater is located at the crossing of very hot gas that is above the combustion chamber and the heat radiation is received directly from the combustion chamber. The steam temperature enter to secondary super-heater was 414 C and exit steam temperature was 541C, pressure 169 kg/cm2. Steam comes out of the secondary super-heater is then used to rotating the HP Turbine.

From information obtained that the pipeline has been operating for about 10 years, namely since 2004. The pipeline has not experienced to be replacement because it is designed to operate for approximately 30 years. This pipe number 2 materials (SSH Pipe) was originally stated to SA-213-T22, but on 2 May 2014 got confirmation that material actually is SA-213-T12. Specification in detail of the pipe and its operational conditions are described in Table 2.1 and Table 2.2.



Another information about operating condition, Inner pipe temperature 414C, Inner pressure 17 MPa and Flue Gas temperature 900C.

Visual Inspection of Super-heater tube can be read on Boiler Tube Research (Super-Heater) Part 2.

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Please visit Boiler Tube Research (Bottom Slope) Part 5 for previous explanation.

Figure 1.15 distribution shows of the von Mises strength right after foreign objects fallen on a pipe with a certain speed. Based on the contour, the conclusion that Von Mises strength maximum that occurs is of 274 MPa. If the value of this strength compared with the value of the yield strength, the initial design specifications (275 MPa), in theory the pipeline haven't experienced plastic deformation. But in fact, the pipeline has been plastic deformation as a result of the collision (see Figure 1.16).






On this simulation, pipe conditioned undergoing exposure to radiation from temperature of a gas combustion of 1,200 degree celcius according to the condition in the field. Based on the temperature contour distribution happened to pipe ( picture 1.17 ), the temperature at the surface pipe still settle at between 100 degree Celsius, which means still under temperature re-crystallizing material. Thus, plastic deformation from impact of foreign matter occurs in condition cold forming. This result in accordance with the metallurgy analysis result before.



The End.

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