DKHG leading producer of seamless heatexchanger tubes.


Carbon & Alloy Steel

Standards
  • ASTM A 179, A192, A209, A210, A334, A199, A213,

Carbon & Alloy Steel Grades
  • T1 / T5 / T9 / T11 / T12 and T22
  • Euronorm equivalents X11CrMo5+NT1, X11CrMo9-1+1, 10CrMo5-5, 13CrMo4-5, 10CrMo9-10
Stainless Steel & Duplex/ Super Duplex

Standards
  • ASTM A 213, A269, A312, A376, B677, A789, A790
Stainless Steel & Duplex/ Super Duplex Grades
ASTM- Grade UNS No. Werkstoff No. En-Standard
TP 304 UNS S30400 1.4301 X 5 Cr Ni 18-10
 TP 304H UNS S30409 1.4948 X 6 Cr Ni 18-10
 TP 304L UNS S30403 1.4306 X 2 Cr Ni 19-11
 TP 316/ TP 316L UNS S31600/31603 1.4401/ 1.4404 X 5 Cr Ni Mo 17-12-2/
X 2 Cr Ni Mo 17-12-2
 TP 316H UNS S31609 - -
 TP 321 UNS S32100 1.4541 X 6 Cr Ni Ti 18-10
 TP 321H UNS S32100 1.4878 X 8 Cr Ni Ti 18-10
 TP 316Ti UNS S31635 1.4571 X 6 Cr Ni Mo Ti 17-12-2
 - UNS S31254 1.4547 X1 Cr Ni Mo Cu N 20-18-7
 TP 904L UNS N08904 1.4539 X 1 Ni Cr Mo Cn 25205
 TP 405 UNS S40500 1.4002 X 6 Cr Al 13
 TP 410 UNS S41000 1.4006 X 12 Cr 13
 TP 430 UNS S43000 1.4016 X 6 Cr 17
 - UNS S31803 1.4462 X 2 Cr Ni Mo N 22-5-3
 - UNS S32760  - X2 Cr Ni Mo Cu W N 25-7-4

Nickel Alloys

Standards
  • ASTM B 161, B 163, B 165, B 167, B 407, B 423, B 444, B 622, B 668, B 729
Nickel Steel Grades
UNS No. Werkstoff No. En-Standard
 UNS NO2200 2.4066 Ni 99.2
 UNS NO4400 2.4360 Ni Cu 30 Fe
 UNS NO6600 2.4816 Ni Cr 15 Fe
 UNS NO6455 2.4610 Ni Mo 16 Cr 16 Ti
 UNS NO6625 2.4856 Ni Cr 22 Mo 9 Nb
 UNS NO8020 2.4660 Ni Cr 20 Cu Mo
 UNS NO8800 1.4876 X 10 Ni Cr Al Ti 3221
 UNS NO8825 2.4858 Ni Cr 21 Mo

Titanium Alloys

Standards
  • ASTM B 388, B 861
Titanium Alloy Grades
  • Grade 1, 2, 3, 7, 11, 12

Non Ferrous

Non Ferrous Heatexchanger Tubes
  • Aluminium Brass, Admiralty Brass, Copper, Nickel 90/ 10, Copper Nickel 70/ 30, Copper Nickel Iron Manganese 66/30/2/2, Aluminium and Aluminium Alloys
Standards
  • ASTM B 43, B 68, B 75, B 88, B111, B315, B395, B466, B 543, B 210, B 234, B 241

Remark
  • In any dimension and shape.
  • Not mentioned standards and grades on request
  • Beside the ASTM standards we can also supply the material acc. to DIN, EN, BS, NFA, JIS, GOST and others.

DKHG offers a large range of seamless heat resisting steel tubes for high temperature and pressure application.

Beside the new production of seamless heat resisting steel tubes some material is also available ex stock.


Carbon Steel & Alloy Steel
Standards & Grades
  • ASTM A 335 Grade P 1, P 2, P 5, P 9, P 11, P 12, P 15, P 17, P 21, P 22, P 23, P 36, P 91, P 92, P 122, P 911,
  • ASTM A 178, A 192/ A 210/ A 106,
  • ASTM A 209, A 200/ A 213 Grade T 1, T 5, T 9, T 12, T 17, T 21, T 22, T 23, T 24, T 36, T 91, T 92
  • A 161 LC, A 161 T1
Stainless Steel

Standards
  • ASTM A 213, A269, A271, A312,


Duplex/ Super Duplex
Standards
  • A789, A790
Nickel Alloys

Standards
  • ASTM B 161, B 163, B 165, B 167, B 407, B 423, B 444,


Titanium

Standards
  • ASTM B 388
Remark
  • In any standard and non standard grade, dimension and shape.
  • Not mentioned standards on request
  • Beside the ASTM standards we can also supply the material acc. To DIN, EN, BS, NFA, JIS, GOST and others.

In addition to the production of straight seamless and welding tubing DKHG manufactures U-Tubes for use in heat exchangers, condensers, pre-heaters and other applications. These U-Tubes are made in accordance with requirements of TEMA RCB-2.31, ASTM A / ASME SA 688, DIN 28179, ASTM B / ASME SB 163, other statutory requirements or specifications.

Beside the production of U-Tubes DKHG is also specialised in the delivery of individually conceived tube and pipe bendings for a wide range of applications.


5 excellent reasons to buy U-Tubes from DKHG

1) You save money and time
  • You only have one contact person
  • You avoid transport damages to the long initial tubes on the way to the bending company
  • You do not have to pay extra costs for the carriage to the bending company
  • You benefit from time saving due to the parallel production of the initial tubes and the U-tubes
  • You may request spare tubes, which we stock for you
  • You save space and time for assembling the heat exchangers as the U-tubes can be removed radius-wise from the wooden combs
2) Surface Quality
  • You receive tubes which are free from oil and grease as well as free from debris
  • You receive a metallic bright surface without discolouration on the inner and outer tube
3) Heat treatment of bending area
  • You can choose between solution or stress relief annealing depending on the material standard
  • On demand, we also include the annealing charts
4) Packing
  • The U-tubes are secured to the transport-rack using wooden combs in order to avoid damage
  • Your incoming material inspection is faster and more efficient due to the accurate packing sorted by radius
5) Quality
  • You receive a detailed test certificate with all the important measures of the bend along with the inspection certificate 3.1
  • You are given a warranty of up to 3 years*

* In line with our general terms and conditions of sale we guarantee defect free materials and good workmanship

Fin tubes are used wherever electric power is generated or raw materials are refined and where efficient cooling is required. Fin tubes are needed in a constantly increasing quanitity for the production of heatexchangers, condensers, coolers and furnaces. The great increase of the thermal efficiency when applying fin tubes allows a substantial reduction in site and costs of such cooling equipment. The surface of such tubes is substantially increased and consequently less tubes are required compared with exchangers with plain tubes.




Description of available types of TECHNIFIN® Tubes
TECHNIFIN® Type “G”

The fin strip is wound into a mechanically produced groove and tightened by backfilling of the base material under pressure. Groove depth 0.4 mm.

Advantages:High fin stability, excellent heat transfer, high operating temparature.


TECHNIFIN® Type “L, KL, DL“

The fin strip is shaped into a „L“ and wound onto the tube surface under tension.

Advantages: Core tube extensivly protected against corrosion by the fin foot, finning of very thin-walled tubes possible.


TECHNIFIN® TYPE "HY"

A smooth core tube is inserted into an aluminium tube.

Advantages: Higher heat transfer coefficient, for same pressure drop compared with „HY“ fin.


TECHNIFIN® TYPE "I"

The fin strip is wound onto the base tube. Typical fin material is steel.


TECHNIFIN® TYPE "N"

The fins are rolled out of the wall of the plain tube. Tube and fin are consisting of one piece.

Advantages: Excellent heattranser, good bending properties, wide rage of material can be used.


TECHNIFIN® TYPE "M"

Manufacturing and advantages as described for type „N“ bit with higher fins.


TECHNIFIN® TYPE "WO"

The fin strip is wound spirally onto the tube and welded continuously to the tube along the spiral root.

Advantages: Strong connection between fin and base tube, prevents loosening of fin because of heat stress, oxidization, corrosion etc., use at very high temperatures possible.


TECHNIFIN® TYPE "WOS"

As per type „WO“ but fins are serrated.

Advantages: Higher heat coefficient. For the same pressure drop compared with „WO“ fin.


TECHNIFIN® TYPE "LFS"

Extruded or drawn fin tube, seamless with two longitudinal opposite fins. Used in boiler wall constructions.

Advantages: Strong connection between fin and base tube, prevents loosening of fin because of heat stress, oxidization, corrosion etc., use at very high temperatures possible.


TECHNIFIN® TYPE "LFW"

I/L or U fins welded longitudianally onto the base tube.


TECHNIFIN® TYPE "S"

Square fins are welded onto a round base tube.


TECHNIFIN® TYPE "DOUBLE S"

Square fins are welded onto two round base tubes.


TECHNISTUD® TYPE "S"

Steel studs are welded by a special process onto the base tube.



Alloy range base tubes - TECHNIFIN®

Supply Range

Carbon Steel ASTM A 179, ASTM A 192, ASTM A 210 Gr. A1, ASTM A 210 Gr. C, ASTM A 106 Gr. B
Low Alloy Steel ASTM A 209 T1, ASTM A 213 / A 199 T11/T12, ASTM A 213 / A 199 T22, ASTM A 213 / A 199 T5, ASTM A 213 / A 199 T9, ASTM A 335 P1 / A 161 T1, ASTM A 335 P11 / P12 / A 200 T22, ASTM A 335 P22 / A 200 T22, ASTM A 335 P5 / A 200 T5, ASTM A 355 P9 / A 200 T9
Stainless Steel ASTM A 213 / A 312 TP 304, ASTM A 213 / A 312 TP 304L, ASTM A 213 / A 312 TP 321, ASTM A 213 / A 312 TP 316, ASTM A 213 / A 312 TP 316L, ASTM A 213 / A 312 TP 347, ASTM A 213 / A 312 TP 316TI, ASTM A 289 / A 790 UNS S 31803, ASTM B 677 Alloy 904L
Nickel ASTM B 161 Ni 200, ASTM B 161 Ni 201
Nickel Copper ASTM B 163 N 04400
Nickel-Chrom-Iron ASTM B 163 N 06600, ASTM B 161 N 08825, ASTM B 468 N 08020, ASTM B 163 N 08800
Copper Alloy ASTM B 75 / B 111 No. 122, ASTM B 75 / B 111 No. 142, ASTM B 111 Ca. No. 443, ASTM B 111 Ca. No. 687, ASTM B 111 Ca. No. 608, ASTM B 111 Ca. No. 706, ASTM B 111 Ca. No. 715
Aluminium Alloys ASTM Alloy 1050 / 1050A, ASTM Alloy 5754, ASTM Alloy 3003, ASTM Alloy 5083

Other material grades can be manufactured upon request.