Dear Members / Friends
I need code reference regarding following Q.1: Client wants to weld pads without releasing water? Q.2: Can weld without releasing water, if yes what problems will appear in future? Q.3: If we can weld, what is the code / standard acceptance criteria? subcontractor filled water for Hydrotest without completing the welding of some pads(plate 9mm) & shoe supports Materials as following 1. Pipe Thickness is 23.83 mm 2. Dia 18" 3. Service : high pressure steam 4. Design pressure/temperature is 53.4 bar/427C 5. Test pressure is 148.2 Bar as per B31.3 |
Hi, You are correct, Minimum refers to the one cycle for which this part will expose until final work shop PWHT. hence mill test certificate shall include this. Max. SPWHT, refers to additional cycles of heat treatment that are reserved for future repairs during equipment lifetime. Again, these simulated no. Of cycles shall be specified in MTC. The idea is we need to make sure that steel mechanical properties are not compromised upon exposure to multiple repairs (i e 4 cycles in your case). One could say, if steel is subjected to 4 cycles and is ok, then it should by defacto be good for one cycle, yet, this is wrong assumption cause mechanical problems and microstructure of materials varies accordingly based on no. Of cycles for which material will expose. This is apparent in alloy steel and especially for impact test values as an example. In your case, this forged CS with properties before PWHT can be understood to be " as forged" condition (i.e. Wit...
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