line up Cold Drawn Steel Tube Duplex Tube

Duplex Tube

Duplex Tube

Feature

Duplex Tube perfectly suits to heat-exchange equipment resistant to decay by primaly fluid or chemical agent.

  1. Outer tube should be low carbon steel tube or stainless steel tube, and inner tube should be brass tube or stainless steel tube.
  2. It is used for heat-exchange equipment, generally special violent corrosion refregerative, for instance, salty water and other chemical, flows inside.
  3. We press color material onto tube ends. Color material is same material as inner tube.

Standard size

(mm)

Outer diameter
(tolerance)

 Thickness (tolerance) Length (tolerance) Length of color (tolerance)
2.4 2.9 3.5 Standard max.
Outer tube Inner tube Outer tube Inner tube Outer tube Inner tube
19.0 (±0.15) 1.3 (+0.4/-0) 1.1 (±10%) - - - - 6,000 (+7.0/-0) 15 (±1.0) 19 (±1.0)
25.4 (±0.20) - - 1.6 (+0.4/-0) 1.3 (±10%) - - 20 (±1.0) 25 (±1.0)
31.8 　- - - - 2.3 (+20%/-0) 1.2 (±10%) 26 (±1.0) 32 (±1.0)

Sample

It is one example (the material and mechanical properties) as follows.

Outer

tube		 Material Chemical composition(%) Tensile strength
N/mm2		 Yield point
N/mm2		 Stretch(%) Relevant standard
C Si Mn P S Ni Cｒ
Low carbon steel 0.18
or less		 0.35
or less		 0.30
  - 0.60		 0.035
or less		 0.035
or less		 - - 340
or more		 175
or more		 30
or more		 STB340

Inner

tube		 Material Chemical composition(%) Tensile strength
N/mm2		 Stretch(%) Relevant standard
Cu Pb Fe Zn Al As Si
Condenser
brass tube		 76.0
  - 79,0		 0.05
or less		 0.05
or less		 rest 1.8
  - 2.5		 0.02
  - 0.06		 0.20
- 0.50		 375
or more		 40
or more		 C6871
BsTF2

Inner

Tube		 Material Chemical composition(%) Tensile strength
N/mm2		 Yield point
N/mm2		 Stretch(%) Relevant standard
C Si Mn P S Ni Cｒ
Stainless steel 0.08
or less		 1.00
or less		 2.00
or less		 0.040
or less		 0.030
or less		 8.00
  - 11.00		 18.00
  - 20.00 		520
or more		 205
or more		 35
or more		 SUS304TB

Usage

  • Electric power system (Condenser)
  • Petroleum refining plant
  • Petrochemical plant

Delivery record

  • HITACHI, LTD.
  • MITSUBISHI HEAVY INDUSTRIES, LTD.
  • SASAKURA ENGINEERING CO., LTD.


Contact us!