Welding Machines

Introduction :
Offered in 50 to 200 KVA capacity, available in longitudnal / circumferential and universal versions. Percision built, sturdy design and robust construction suitable for high production and uninterrupted service in the manufacturing of drums, barrels, silence, fuel tanks, transformer radiator, water heater & auto rims, etc.

These machines are always made to specific customer requirement with highly sophisticated & leak proof joints.

Standard Rating :
50,75,100,150 and 200 KVA

Construction :
The main frame of the machine is of heavy rigidly re-inforced & robust welded steel construction. It combines a compact streamlined appearance with maximum resistance to mechanical deflection. The welding transformer is enclosed in the main frame and is easily accessible, for inspection.

STANDARD THROAT DEPTHS (mm) :
280, 460 & 600 (other throat available on request)

Normal Working Height :
900 (mm)

WELDING TRANSFORMER :
Transformer of a special type, water cooled, having core of high grade electrical steel, primary and secondary coils of solid electrolytic copper of ample section, heavy duty class ‘F’ insulated, impregnated and tropicalised suitable for withstanding continuous temperature of 140º C.

CURRENT CONTROL :
Transformer primary coils provided with taps brought out to tap change links for adjustment for welding current in a 6 step from 50 to 100%. Tap change links are enclosed behind machine door and are easily accessible for variation of welding heat.

COOLING SYSTEM :
Transformer, secondary connections, arms and electrode wheels are water cooled. Internet water cooling piping with flow adjusting values for each circuit and discharge to an open drain pot for visual observation of flow are provided in the machine.

ELECTRODE :
Circular disc type top and bottom welding Electrodes.

ELECTRODE CONTROL SYSTEM :
Upper electrode is actuated by hand lever to provide electrode force.

ELECTRONIC CONTROLS :
Seam welders are provided with solid-state electronic controls housed in a well-designed sheet steel cabinet. The standard design of the cabinet is suitable for mounting it on the sidewall of the machine; floor mounting shall also be provided a request. The control knobs and panel are elegantly arranged, provided maximum convenience to the operator. The front panel is protected from misuse by providing a transparent guard door. All internal wiring is easily accessible for servicing. The circuit design is versatile enough for almost all type of requirements and consists of the following facilities.

• A squeeze time control to select the delay between initiation of the foot switch and the start of the weld. Timing is adjustable from 2-25 cycles, continuous
• Synchronous (digital) timing control of 1-9 cycles “ON” and 0-9 cycles “OFF” both in steps of one cycles each.
• Heat control circuit based on phase shifted firing of thyristors which enable continuous adjustment of current between 10% to 100% of then value available from welding transformer.
• High power switches device consisting of 2 Thyristors connected in inverse parallel mounted on water-cooled heatsinks. The sizes of the thyristors are chosen to watch the KVA of the transformer and the devices are of ample capacity to withstand momentary overloads. Protection devices for high voltage surges and a thermoswitch (for inhibiting the operation if the temperature of the thyristor pad rises above a preset limit) are incorporated.
• Hold time to provide a delay between stoppage of weld and separation of electrode wheels. Range of adjustment is 1-9.

WELD INITIATION :
By means of operators foot switch connected to a low voltage safe initiating circuit.

MOTOR DRIVE SYSTEM :
Machine can be supplied with either A.C. or D.C. motor drive system as per customers choice.

• D.C. Motor driven system consists of an infinitely variable speed, reversible D.C. Motor, variac, rectifier & protective fuses system with reduction gear unit to provide stepless speed variation.
• A.C. Motor driven system consists 3-phase induction motor speed as constant.

Note : Machine shall be supplied with A.C. MOTOR DRIVE SYSTEM AS STANDARD UNLESS SPECIFIED otherwise by the customer.

SERVICE REQUIREMENTS :
Customer to provide the following service facilities :-
POWER SUPPLY :

• For Transformer : 415 V, Single phase, 50 cycles (suitable for connection to 2 lines of 3 phase supply). Main supply cable for transformer connection. Disconnect switch with fuses of recommended rating.
• For Motor : 415 V, 3 phase, 50 cycles or 230 V, single phase, 50 cycles or 230 V, single phase, 50 cycles for D.C. motor drive, depending on the drive system selected supply cable 1.5 sq. MM 4 core, TPIC switch fuse unit 500 V, 15 Amps, with fuses of 5 Amps for D.C. motor Drive system.

COMPRESSED AIR :
Supply of air recommended flow volume at minimum pressure of 5.6 kg/cm2 (80 psi) by the customer.

TECHNICAL SPECIFICATIONS :

• Spot and nut projection possible on the same machine
• Robust construction – less vibrations – no maintenance of controller broad / connectors.
• Controlled delivery of welding current by made constant current feedback controller.
• Quantity watch on every spot. Weak or faulty spot highlighted instantly.
• Error and weak spot alarm buzzer.
• Fused copper laminate flexible links for lifetime use
• High speed cylinder operations gives better cylinder follow up.
• Electrode movement made precise by LM bearing.
• Engineered for minimum downtime.

TECHNICAL SPECIFICATIONS :

Rated power @ 50% Duty Cycle

KVA

35

50

75

100

Secondary Voltage

Volt

4.8, 6.4

5.9, 7.4

6.5, 9

6.7, 9

Welding Current Max

KA

12

13.5

15

20

Control Type

Secondary feedback constant current control

Time Setting Least Count

Millisecond

20

20

20

20

Throat Depth

mm

250-300

250-300

250-300

250-300

Arm Gap Max

mm

300

300

300

300

Electrode Force min - max

Kg

150 to470

150 to470

150 to470

150 to470

Free Air Consumption (@1 bar) for

100 Spots and 25mm Stroke

Liters

250

250

250

250

Strokes Per Second Max at No Weld

Nos.

6

6

6

6

Cooling Water Pressure

Kg/cm. Sq

2

2

2

2

Cooling Water Flow Rate Min

It/min

9

10

10

12

Welding Capacity (indicative comparisons only)

Sheet Metal CRCA

mm

2/2.5

2.5/3

3.3

4.4

Sheet Metal HR

mm

2/2.5

2.5/3

3.3

5.4

Sheet Metal SS

mm

1.2/1.5

1.2/2

2.2

2.5/2.5

Projection Nut Welding

mm

M8

M10

m12

m16

Dimensions Depth x Width

mm

1050 x 410

1050 x 410

1050 x 410

1050 x 410

Height

mm

1750

1750

1750

1750

Weight

mm

500

510

520

600

Note : Optional low cost voltage compensation control is also available.

• High weld abilities are achieved with special type of transformer.
• Ability to weld thick material at low speed using short length arms.
• In Manually operated machine at low speed using short length arms.
• Easy maintenance.

Construction :
The unit is of robust construction sturdy heavy rigidly reinforced welded steel construction. It combines a compact streamlined appearance with maximum resistance to mechanical deflection. The transformer enclosed in the main frame and is easily accessible, for inspection.

Welding Transformer :
Manufactured from high grade materials of copper strips and sections, water cooled with class ‘F’ insulation with standing continuous temperature rise of 140`C. The coils are impregnated and tropicalised.

Current Control :
By tap method with 8 tap adjustments on primary of the main transformer having current control from 50% to 100% in 8 steps.

Cooling system :
By tap link method with 8 tap adjustments on primary of the main transformer having current control Electrodes, Electrode holders, Arms, Transformer are all water cooled with one single water-cooling circuit.

Electrode Control System :
Upper electrode is actuated by foot lever or by air cylinder. The electrode force can easily be calculated in both systems. Air system is provided with gauge and manual system with calibrated spring. All air accessories such as filter, lubricator, regulator, gauge, solenoid valve and speed valve are incorporated.

Maximum Operating Speed :
Machine is mechanically capable of attaining 60 spots per minute.

TECHNICAL SPECIFICATIONS :

VIRDI's MIG welders are used universally in light and heavy fabrication workshops, shipbuilding & auto industries, in manufacture of stainless steel, mild steel, copper vessels & container in chemical and allied industries.

These VIRDI CO2/ MIG equipment are designed and engineered for CO2 welding of mild steel, low alloy steels and MIG welding of high alloy steels and light metals.

Salient Features :

• Welds mild steel, stainless steel wires & bronze alloy wires
• Suitable for solid wires as well as fluxed cored wires
• Easy connection system for torch plug-in to wire feeder
• Most reliable / easy / maintenance wire feeder with roll / quick release type
• Adjustable spot time control available on request
• Coarse / Fine controls for proper selection of voltage
• Sleek & most flexible torch
• Wire feeder units are normally supplied as separate unit to give greater area of operation & flexibility. However in-built version is also available (on request)

Technical Specification :