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 ...
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<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 Unitsi) Minimum 8 mm thick steel plates <strong>for</strong> gas ducts from APH outlet to ESPinlet and minimum 6 mm thick steel plates <strong>for</strong> gas ducts from ESP outletto the chimney inlet.ii) Minimum 5 mm thick steel plates <strong>for</strong> air ducts.iii) A corrosion allowance <strong>of</strong> 1.5 mm shall be considered <strong>for</strong> stress calculation<strong>for</strong> the flue gas ducting.iv) Duct stiffening shall be by means <strong>of</strong> rolled sections.v) The thickness <strong>of</strong> the duct plate shall be suitably increased, if required, inthe transition zone at steam generator outlet where the flue gases changedirection, to increase the wear life <strong>of</strong> the duct plates.vi) Interconnection ducts shall be provided in air and gas system <strong>for</strong> flexibility<strong>of</strong> plant and equipment operation as necessary.7.2.5 Material <strong>of</strong> constructioni) Duct plates, turning vanes,per<strong>for</strong>ated platesASTM A 36 or equivalent (suitablealloy steel <strong>for</strong> gas temperature above400 0 C)ii) Structural shapes ASTM A 36 or equivalentiii) Pipe struts, trusses, bracing ASTM A 53 or equivalent seamlesssteel pipeiv) Erection tools <strong>for</strong> ducts ASTM A 307 or equivalentv) Bolts <strong>for</strong> connection tostructural steelvi) Stainless Steel ASTM A 316 L or equivalentvii) Access & inspection doors Rein<strong>for</strong>ced steel plates7.2.6 Insulation & laggingASTM A 325, AISIA 325 (frictiontype) or equivalenti) Thermal insulation shall be applied to all air/ gas ducts to comply with therequirements as specified elsewhere in this document.ii) Acoustic insulation shall be used on air and gas ducts to restrict the noiselevel to specified values.7.2.7 Expansion jointsi) Metallic type expansion joints suitable <strong>for</strong> the service conditions shall beprovided. The expansion joint design shall con<strong>for</strong>m to the requirements <strong>of</strong>the EJMA <strong>Standard</strong>s.ii) The expansion joints shall be <strong>of</strong> heavy duty construction. The expansionjoint material shall be compatible with the flowing medium, the externalenvironment and the operating temperature. Suitable corrosion anderosion allowances shall also be taken.59
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