Outline of Rail Gas Pressure Welding Apparatus
Rail gas pressure welding was started in 1953 in Japan. Since then, rails have been made longer to prevent running noises, to improve riding comfort, and to reduce rail track maintenance cost due to higher train speed. In 1974, a small type, lightweight rail gas pressure welding apparatus was developed. This apparatus joins rails under pressure by heating butted rail ends with an oxy-acetylene flame.
This maximum temperature of the rail weld interface is 2200°F to 2400°F (1200℃ to 1300℃).
Consequently, both base metals are joined without any fusion and the strength of the weld joint is almost the same as that of base metals.
Gas pressure welding is mostly mechanically accomplished. Therefore, joining strength is even and highly reliable.
The same strength can be obtained by either gas pressure welding or flash butt welding.
In this welding method, on-track welding, as well as shop or field depot welding, are available.
A trimmer device is incorporated in the apparatus to remove burrs right after gas pressure welding, and this way, the soundness of the joint can be checked.
This apparatus can be used also to weld head hardened rails (including part of alloy steel rails).
In this case, a post-weld heat treatment is necessary for obtaining weld joints as good as base metals.
Features
This apparatus is geared to obtain uniform weld quality. Because burrs are cut off through extrusion while during high temperature right after gas pressure welding when a defect such as a weld flaw occurs in the weld joint, it is opened during extrusion for trimming and this is effective for quality control.
Weld Strength and Hardness
Because heating temperature is controlled below the steel melting point and no filler metal is used, weld strength is as high as that of the base metal. The weld joint of the head hardened rail is softened due to welding heat. However, a post-weld heat treatment device can be used to restore the hardness of the welded part as high as that of the base metal. Please refer to page 8 for details.
Workability
This apparatus is designed for compactness, lightweight, and mobility to make the on-track application possible, not to speak of shops or field depot welding. Pressure welding efficiency with this apparatus is remarkably high.
Economy
Main consumables are oxygen, acetylene, fuel for the generator and grinding stones. Cost per weld is far more economical than that of other welding methods even when amortization for machines and labor cost are considered.
Welding Method
|
1. Rail End Surface Grinding
Grinding of the rail end surface is necessary for the rail gas pressure welding.
|
|
2. Setting of Pressure Welding Apparatus
The welding machine is set on the rail, and the alignment checked of the rail is can take place.
|
|
3. In Process of Pressure Welding
The welding machine pressurizes and heats the butting part of all surroundings with a special burner by oxy-acetylene flames and both rails are joined. |
|
4. Finish of Pressure Welding
After setting the trimmer, extinguish the fire of the burner and stop upsetting, release the clamp on the right side. |
|
5. Trimming
Hot shear removal of the burr of the whole circumference with a trimmer. |
|
6. Welded Part Right After Pressure Welding
After trimming, the welder has to check the crack at the joint point.
|
Model
Main body & Operation unit
Gas controller
Recommended Model of Main body & Operation unit
Specification
Main body & Operation unit
| Model | Manual type | Semi-Auto type | |||
|---|---|---|---|---|---|
| TGP-5 | TGP-5-B | TGP-8-S2-T（C） | |||
| Main body | Clamping force | Max 230kN | Max 230kN | Max 230kN | |
| Upset force | Max 330kN | Max 330kN | Max 330kN | ||
| Size (mm) | L1,310×W550×H740 | L1,380×W570×H775 | L1,350×W570×H660 | ||
| ※Weight | Carrying | 230kg | 270kg | 290kg | |
| Working | 300kg | 350kg | 360kg | ||
| Appearance |
|
|
|
||
| Hydraulic pump | Power supply | 1.5kW, 200/220V, 50/60Hz, 3-phase | 2kW, 200/220V60Hz,3-phase | ||
| Other than the above voltage can be manufactured. Please consult us. | |||||
| Max. pressure | 70MPa | 70MPa | |||
| Size (mm) | W600×D550×H850 | W600×D550×H850 | |||
| Weight | 120kg | 135kg | |||
| Appearance |
|
|
|||
| Operation unit | Operation method | Manual operation of hydraulic changeover valve | Touchscreen operation | ||
| Size (mm) | W725×D575×H700 | W201×D97×H230 | |||
| Weight | 65kg | 1kg | |||
| Appearance |
|
|
|||
| Operating environment | Temperature: 0 ℃ (-10℃) to 40℃, humidity: 20 to 85% RH, but no condensation.
In ( ), cold district specification type：【TGP-8-S2-TC】 |
||||
| Characteristic | ・Light weight type | ・Rigidity type
・Replaceable consumable parts |
・Hydraulic operation is automatic
・Welding record ・Automatic control of closure welding ・Hydraulic hose reduction |
||
DESIGN/PARTS may be changed without notice.
※Carrying：at the carrying / without hydraulic equipments.
Working：at the working / with hydraulic equipments.
Gas controller
| Model | Analog type display | Digital type display | |
|---|---|---|---|
| MA-10255 | DGF-A（B） | DGF-C | |
| Power supply | Unnecessary | AC100-240V Single-phase AC100-240V | Single-phase |
| Operation method | Manual adjustment
(Pressure & flow adjustment) |
Manual adjustment
(Flow adjustment) |
Automatic setting |
| Size (mm) | W400×D420×H422 | W440×D355×H265 | W510×D415×H300 |
| Weight | 21kg | 13kg | 23kg |
| Installation | Horizontal installation | Horizontal installation unnecessary | Horizontal installation unnecessary |
| Display |
|
|
|
| Appearance |
|
|
|
| Operating environment | Temperature: -10℃ to 40℃, humidity: 20 to 85% RH, but no condensation.
（Oxygen and acetylene gas should be used with sufficient heat retention.） |
||
| Characteristic | ・Power supply is Unnecessary | ・Easy to read digital display
・Data of flow rate can be recorded 【Separate Recorder is required】 ・Lineup of battery type |
・Easy to read digital display
・Data of flow rate can be recorded 【Please connect to TGP – 8 – S2, or a separate recorder is required】 ・Automatic flow control function by TGP-8-S2 |
DESIGN/PARTS may be changed without notice.
Sales Performance of the Apparatus
