During installation of the type developed VNIIESO UDC-204 for mechanized welding butt water-gas supply pipe for installation of sanitary equipment at the construction site. Set includes a portable welding head, a portable pneumatic device and the power unit. Weight 8.5 kg of the welding head. The welding head consists of a clamping mechanism pipes, precipitation, and the drive system of the excitation magnetic field. In order to simplify the design of the welding head, reducing its size and providing welding in confined spaces clamping mechanism installed so that they, along with welded pipes for the heating of the entire process razo remain fixed relative to each other. Clamping of pipes is done by hand high-speed three-hinged clamps. Drive Air - Pneumatic diaphragm placed between two covers. The pressure is transmitted to the diaphragm and the plunger through a lever welding head - on the jaws with the trumpets. The excitation system of the magnetic field is made detachable in the radial direction and consists of four coils, creating a gap between the pipe radial magnetic field, providing the movement of the arc along the edges of welded pipes. Field coil does not have a separate power source and connected in series in the welding circuit. To set the gap between the pipes before welding is a rotary knife. Pneumatic hand-held device consists of a receiver, and electro-pneumatic valve controlling the compressed air from the compressor to the welding head. The unit includes a power supply of the arc-welding a standard DC-DC converter, power supply, compressed air - compressor, power equipment and a drum for cable and hose. The welding head is connected to a pneumatic device, wires and a hose length of about two meters. The length of the pneumatic device to the power supply unit - 75 pm For ease of installation conditions in the welding wire has a small cross section (25 mm2). The presence of relatively high voltage drop across the welding wires makes it necessary to use welding inverter 500 and the welding current at a nominal 260 a. The block provides the necessary hardware cycle of welding: Welding current switch, adjustable time delay of heating, the inclusion of sediment pressure after a predetermined time warming up to the draft of a shock. Work on the installation as follows: the ends of welded pipes are clamped in the welding head. Carbon rod is excited by an electric arc between the edges of the pipe and then automatically go through the following processes: melting of the edges of the rotating arc sediment off the welding current and removal of pressure precipitation. When working with the installation must comply with safety regulations and fire regulations established for welding with an open arc. During the welding process should not touch the pipes being welded. Tensions between the pipes in the heating process has the same magnitude as between the electrode and the workpiece in manual arc welding, ie, in the 26-28. Welding can be carried in any position at a distance of not less than 30 mm from the wall. Welded joints are of equal strength base metal. Grat is evenly distributed around the perimeter of the pipe, the quantity did not exceed 1-15 mm. When hydraulic tests on the density of the welded specimens withstand pressure of 300 kg/cm2. For welded tubes, resistance welding, all acceptable methods of quality control is used in resistance welding. The most widely used type of installation UDC-204 is, in welding the heating systems of buildings. Mounting and installation of heating systems for welding is performed, usually in advance. Billet risers are manufactured at the plant. Implementation install UDC-204 provides the following economic benefits:
- Excludes costs for oxygen, acetylene, electrodes, etc., the installation of pipe welds only by heating the ends of themselves and their squeezing after heating;
- increased productivity and quality of assembly and welding operations;
- reduced requirements for the qualification of welders, welder instead of V-VI of the discharge, performing manual arc welding, installation services performed by the operator level III;
- reduction of harmful substances released during welding galvanized pipe, due to the short duration of the process and the small area heating.
- The installation can be welded pipes with diameter 21.3 mm and 26.8 mm with wall thickness up to 3.2 mi. In the transition from one pipe size to another is a change of jaws and changing the heating time.
- Rated welding current of 260 a. The amount of current during welding of pipes of all sizes remain constant.
- Type of welding current - constant.
- Duty cycle - 2.5%.
- The voltage on the arc - in the 25-26.
- Air-pneumatic actuator.
- Air force, 1,800 kg at a pressure of compressed air - 5.5 kg/cm2.
- Welding time - up to 3 seconds.
- Plant capacity - 30 welds / hr.
- Unit weight: welding head - 8.5 kg; perenosnoo receiver - 8.0 kg; aggregate supply - 1000kg.
- Dimensions: welding head - 195x185x550, a portable receiver - 252 X236 X 360; aggregate supply - 1470H900H1490.
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