Tubes with internal ribs - MARGO Rury i złącza stalowe

Seamless tubes with internal ribs (internal riffling) are made by cold drawing. They are used as boiler tubes or heat exchangers tubes.

Steel grades according to EN 10216: P235GH, 16Mo3

Compared with tubes that have a smooth internal surface, tubes with ribs offer the customer many advantages:

improved level of heat transfer even with a higher share of steam;
very good level of heat transfer, retained also at lower medium flow;
lower temperature of tube walls = lower risk of tube’s distortion;
internal riffling prevents from sedimentation of solid particles present in the medium = lower risk of corrosion process = increased lifetime of a tube;
improved heat transfer by a suitable optimization of the riffle geometry.

Parameter	Range [mm]	Range [inch]
Outside diameter D	18-72	.750-3.000
Tube wall thickness T	1-6,5	.047-.250
Number of ribs	6-8
Rib height h	0,3-1,0	.016-.047
Rib width at the top f	3-8	.125-.313
Rib side angle ß	30°
Rib radius r	0,1-0,15	.004-.006
Rib pitch angle a	25°-35°
Rib pitch length (360°)	depending on outside diameter
Distance of rib centers in the longitudinal direction	upon agreement
Rib width at the top	upon agreement
Width of the distance between ribs at the top	upon agreement
Inside tube circumference	upon agreement
Transversal tube diameter	upon agreement
Tube length	upon agreement