notice inviting tender for supply of return bend , return bend , size-4 nb x sch 80 , 180 degree , short radius , seamless 1 . moc: astm a403 wp321h; 2 . dimensions: as per asme b16 . 28 . 3 . end finish: bevelled conforming to ansi b16 . 25 . 4 . return bends shall be free from surface imperfections . 5 . return bends shall be pickled free from scale . 6 . all 321h grade return bends shall be solution annealed at a minimum temperature as per astm a 403 . the grain size range shall be as per astm e112 no . 7 to no . 4 . 7 . the wall thickness at all points shall be at least 87 . 5% of the specified nominal wall thickness . thickness testing shall be witnessed by tpi inspector . 8 . all 321h grade return bends shall be given a stabilization heat treatment subsequent to the solution anneal . 9 . vendor shall carry out dp test of complete outer surface of 100% return bends which shall be witnessed by tpi inspector . notes: 1 . vendor shall engage one of the tpi agency from lris/tuv/bv/irs for final inspection . 2 . each return bend shall be supplied with proper third party stamping . 3 . qap shall be submitted for rcf approval after po placement < ( >&< ) > before starting the actual manufacturing process . 4 . all the test certificates shall be endorsed by tpi inspector . 5 . vendor to furnish all relevant documents / inspection records in original which shall comprise of test certificates for chemical composition and physical properties of material , metallography for grain size , heat treatment records , tpi inspection and final release note . 6 . at a minimum , all items shall bear legible marking giving name or brand of manufacturer , the grade of material from which the item has been made , specification number , heat number < ( >&< ) > heat treatment lot identification . for austenitic materials , the marking ink or paint shall not contain any harmful metal or metal salts such as zinc , lead or copper which cause corrosive action on heating . , tpi charges: all arrangement for tpi inspection & visit shall be done by vendor . vendor shall engage one of the tpi agency from lris/tuv/bv/irs for final inspection .