METHOD OF PRODUCING LARGE-DIAMETRE GAS-AND-OIL TRANSFER PIPES Russian patent published in 2010 - IPC B21C37/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy, namely to production of large-diametre thick-sheet steel pipes for oil and gas mains. Proposed method comprise heating slabs, rolling them into sheets and hot-rolling said sheets to produce tube producing tubular billet. Prior to producing the latter, sheet edges are hot-rolled in vertical edger followed by removal of edges and chamfers for welding by thermo milling. Tubular billet produced, it is cooled in muffle refrigerator under controlled cooling conditions. Produce tubular biller cooled down, its electrically welded, trimmed, leveled and hydraulically tested. Producing tubular billet and producing tube proper are separate processes. Edges are rolled in vertical edger with relative reduction over the width of 2-15%.

EFFECT: higher efficiency and quality, expanded applications.

2 cl, 1 dwg