GHDG-800 fixed large flash butt rail & turnout welding machine

GHDG-800 fixed large flash butt rail & turnout welding machine with high DC power supply, is used in fixed plant to weld short rails to rails of 500 meters and more, or to weld turnouts to rails (Such as high-manganese steel frogs), or weld large alloy parts.
This type of welding machine can weld any type of rails and frogs, accurately align the rails or frogs, effectively prevent the rail from slipping during the upset forging, immediately trim after upsetting, and the power supply performance is stable and uniform.
This welding machine can realize any combination of continuous welding process, pulsation welding process and preheating welding process.

Part A: The basic information
Name of the machine: Updated Fixed large Flash Butt Rail & Turnout Welding Machine
Model of the machine：DGHG-800
Machine composition: It is mainly composed of water-cooling system, hydraulic system, welding main circuit, electrical control system, welding head, software system and other parts.

Part B: Scope of application
This welding machine is suitable for the processing of flash butt welding of large profiles, especially for the welding of turnouts and rails.

Part C: How it works
The welding machine has four independent clamping devices, which can accurately clamp the welded workpiece with irregular cross-section and keep it horizontal. The welding machine has a centering function, which can adjust the relative position of the workpiece to be welded to complete high-precision butt welding.

During welding, a strong DC current is supplied to the workpiece to be welded through the clamping electrode, which effectively reduces the welding resistance. When the welding surface of the workpiece to be welded reaches a sufficient temperature, upsetting is performed to complete the welding. The upsetting mechanism can distribute the forging pressure on the welding surface to ensure the welding accuracy.

Part D: Welding range
Welding of turnouts and rails conforming to the national standards of China, the standard of European Union, Russian standard, the standard of United States , etc., including the welding combination of rails and rails, rails and turnout frogs (with austenitic spacers, high-manganese steel spacers).
Weldable cross section: up to 16000 mm2
Tensile Strength: 800 – 1300 N/mm2
Welding Efficiency: max 20 joints/hour

Part E: Technical Parameters

E.1 Power Requirements
Power Supply voltage: 400±15V
Number of phases of power supply: 3
Frequency of power supply: 50 Hz

E.2 Transformer
Transformer capacity: 630 kVA
Maximum voltage drop: 10%

E.3 Main electrical parameters of welding machine
Transformer rated primary voltage: 400 V
Phases of primary voltage: 3
Frequency of primary voltage: 50 Hz
Auxiliary voltage: 230 V
Number of phases of auxiliary voltage: 2
Frequency of auxiliary voltage: 50 Hz
Transformer power rating: 580 kVA
Startup Duration Factor (ED): 50%
Secondary idling DC voltage: 7.7 V
Transformer Transforming Stages: 1

E.4 Technical parameters of mechanical parts
Maximum upset force : max. 1000 kN
Clamping force: max. 2000 kN
Electrode pressure: max. 1000 kN
Clamping stroke: max. 120 mm
Upset stroke: max. 50 mm

E.5 Technical parameters of hydraulic system
High pressure (pump pressure): 140 bar
Low pressure: 40 bar System pressure: 130 bar
Accumulator charge pressure: 40 bar
Volume flow with pump pressure : 190 L/min
Fuel tank capacity: 400 L

E.6 Technical parameters of water-cooling system
Water quality requirements: clean, filtered, calcium-free, neutral to low alkaline.
Flow: 150 L/min
Cooling water pressure: 4 – 6 bar
Entry water temperature: max 25 °C
Temperature Rise: 7 °C
Cooling power: 63000 kcal/h
Filtration accuracy: 100 μm
dH – value, total hardness:  9 – 15 °
dH – value, carbonate hardness: max. 9 °
pH – value: 7 – 8
Solid fraction: max. 50 mg/L
Sum of salts (sulfates/nitrates/chlorides): max. 70 mg/L

Part F Main features

*Low welding resistance for high power DC welding power is used
*Independent three-stage cooling system is used, which resulting in easy overhaul and monitor, preventing cross-contamination, and have high cooling efficiency
*High alignment accuracy for closed-loop automatic alignment is used
*With fault self-diagnosis
*With temperature detection and thermal compensation
*The multi-mechanism welding process can be used to adjust the welding process to a greater extent according to the process requirements.

Part G Structure view