Multi lead rifle seamless tubes - internal ribs

Multi lead rifle seamless tubes are made by cold drawing. Compared with tubes that have a smooth internal surface, tubes with internal rifles offer the customer many advantages:
(a) the degree of the heat transfer is improved even at the higher share of steam,
(b) the degree of heat transfer is very good and preserved even at a lower
flow of the media,
(c) temperature in the tube walls is being lowered therefore the risk of the wall
failure is lowered too,
(d) at the same time the space is created for an improved heat transfer by a suitable
optimization of the rifle geometry.


Dimensions of the multi lead rifle seamless tubes

OUTER DIAMETER (OD)18.0 - 72.0 mm
0.750 - 3.000 inch
WALL THICKNESS (WT)0.5 - 6.5 mm
0.047 - 0.250 inch
See tube sizes

The steel grades for the multi lead rifle seamless tubes

EN 10216P235GH, 16Mo3.
Marking system for steel grades according to EN

JIS G3461
JIS G3462

STB340, STB410, STB510.
STBA12
ASTM, ASME A/SA192, 209, 210, A 213
and other corresponding grades for tubes intended for pressure equipment

From the dimensional and weight point of view, the tubes with internal ribs are characterized with its parameters shown in the table below. In the table there are basic dimensional limits shown. The specific parameters are subject of an agreement between the supplier and the customer.

Symbol
Parameter
Range
mm
inch
OD
Outside diameter
18 - 72
0.750 - 3.000
WT
Wall thickness
1 - 6,5
0.047 - 0.250
Number of ribs
6 - 8
h
Rib height
0,3 - 1,0
0.016 - 0.047
f
Ribs width at the top (cross section)
3 - 8
0.125 - 0.313
ß
Rib side angle
30°
r
Rib radius
0,1 - 0,15
0.004 - 0.006
a
Rib pitch angle
25° - 35°
Rib pitch length (360°)
depending on outside diameter
Distance of rib centers in the longitudinal direction
upon agreement
s
Rib width at the top (longitudinal section)
upon agreement
Width of the distance between ribs at the top
upon agreement
Inside tube circumference
upon agreement
Transversal tube diameter
upon agreement
Length of tube
upon agreement

Multi lead rifle seamless tubes

Multi lead rifle seamless tubesMulti lead rifle seamless tubes (internal ribs)Multi lead rifle seamless tubes - internal ribs