Mono- and bimetallic tubes with spiral ribs from ferrous and non-ferrous metals, special alloys and bimetals, most effective by heat transfer and economical by manufacturing, now can be produced at the cross-screw rolling mills designed by VNIIMETMASH.

Due to the introduction of rolling, ribbed monometallic tubes from aluminium got wide spreading in heat exchange equipment instead the tubes from copper-brass alloys. Where it is impossible to use aluminium tubes by service conditions, bimetal ribbed ones from different metals: brass-aluminium, copper-aluminium (with aluminium on the outside) are used. The ribbing factor (the ratio of the area of the outside surface of a ribbed tube to that of a plain tube with diameter equal to rib base) is 10-20.

The mills for ribbed tubes rolling designed by VNIIMETMASH operate successfully at the works in Russia, CIS, Japan, France and other countries.

Mono- and bimetallic ribbed tubes are used in power engineering, chemical, oil, ship building and other branches of industry.

The mill ХПТР 28-40 from the 2002 is exploited at the Penzahimmash, Russia.

Monometal tubes d/s = 5...10; t = (1...2) x S h = (1...4) x t; l<=6000 mm	Bimetal tubes D/s = 10...15; t = (1...3) x S h = (1...4) x t; l<=6000 mm
Low ribbed tubes d/s = 8...12; t = (0,5...1) x S h<=t; l<=6000 mm	Profile tubes d/s = 10...20; t = (1...3) x d h<=0,1 d; b S; l<=6000 mm

The productivity of this mills according to dimensions and types of ribbed tubes is 1-10 m/min. The prime cost of rolled ribbed tubes only by 15% exeeds the cost of initial billets plain tubes whereas their use 1,5-2,5 times reduced the consumption of plain tubes by mass and 2-4 times by length.

VNIIMETMASH possesses of capacities for the production of mill ХПТР, of heat exchange ribbed tubes and tubes with circular and screw grooves. Monometal ribbed tubes are made from aluminium and copper. Bimetal ribbed tubes are made from aluminium (outer tube), carbon, stainless steel, brass, copper (inner tube). Low ribbed and profile tubes (with circular and screw grooves) are made with plain ends without deformation and parts without ribs, located along the length of tube.

Cooperation proposals:

• Equipment and auxiliaries delivery;

• Technology mastering, arrangement and repairing of equipment;

• Ribbed and profile tubes manufacturing according to customer's drawings.