Standard Technical Features of BTG System for Supercritical 660 ...
Standard Technical Features of BTG System for Supercritical 660 ...
Standard Technical Features of BTG System for Supercritical 660 ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Standard</strong> <strong>Technical</strong> <strong>Features</strong> <strong>of</strong> <strong>BTG</strong> <strong>System</strong> <strong>for</strong> <strong>Supercritical</strong> <strong>660</strong>/800 MW Thermal Units6.5.2 Pressure partsb) The casing/ pent house and its supporting system shall be capable <strong>of</strong>taking additional loads due to accumulations <strong>of</strong> ash upto 300 mmheight or actual expected (in between two overhauls <strong>of</strong> the units),whichever is higher. This additional load is over and above otherloads considered <strong>for</strong> casing design. The ash density <strong>for</strong> the purpose<strong>of</strong> ash loading shall be at least 1350 kg/m³.c) The pent house shall be provided with arrangement <strong>of</strong> fans <strong>for</strong>cooling by supply <strong>of</strong> fresh air.i) MaterialsThe material used <strong>for</strong> Steam Generator components i.e. boiler pressureparts including boiler tubing, headers, separators, piping, vessels, valves& fittings etc. and other components shall be equal to or better than thefollowing unless specified otherwise:Design metal temperatureMateriala) Upto & including 400 0 C Carbon steel to ASME SA-106 Gr. B/Cor SA 210 Gr. A1/ Gr. C or equivalent.b) Upto & including 550 0 C Alloy steel to ASME SA-335: P-11/P-12/P-22; ASME SA213:T-11/T-12/T22/T23 or equivalent.c) Upto & including 605 0 C Alloy steel ASME SA-335/213:P-91/T-91, T-92, or equivalent.d) Above 605 0 C Austenitic stainless steel, Super 304H,TP347H or equivalent.ii)The design <strong>of</strong> all pressure parts (tubes, headers, separators, vessels etc.)shall meet the requirements <strong>of</strong> Indian Boiler Regulations (IBR).iii) Design pressure <strong>of</strong> the steam generator pressure parts shall be at least1.05 times the maximum operating pressure, or as required by IBR/otherinternational codes, whichever is higher.iv) The thickness <strong>of</strong> the pressure parts (steam and water tubes/headers,separators, pressure vessels etc.) shall be calculated using IBR<strong>for</strong>mulae/factor <strong>of</strong> safety etc. (and not as per codes/<strong>for</strong>mulae acceptableto IBR). Minimum tube thickness at the bends in no case shall be lessthan the minimum required tube thickness <strong>for</strong> the straight tubes. For thispurpose appropriate thinning allowance shall be considered whilecalculating the thickness <strong>of</strong> the bends. Additional erosion allowance onthe calculated tube thickness shall be provided at specific locations asspecified.31
Change language