Line Pipe Seamless API 5L Grade B: (As Per Specification) (Under Single Stage One Envelope Bidding Procedure) ine Pipe 8 NB x 0.500 WT Bevelled Ends, Qty=90 Metre. Line Pipe 4 NB x 0.237 WT Bevelled Ends , Qty=120 Metre Line Pipe 2 x 0.154 WT Plain