Whether it is gas, arc or resistance welding equipment, little preventive maintenance can save us from large future expenditures.
Barely any modern industrial plant is without welding equipment for both production and maintenance today.
Welding has become a necessary step in every metal fabrication process and in recent years its importance in the maintenance of the plant has increased to the point where it cannot be ignored.
Today the need to keep welding equipment longer is more than before because replacement parts are more expensive.
It can be achieved better production from welding equipment by correct maintenance
Many types of welding equipment are in use in modern plants. The use of such equipment requires separate maintenance procedures.
Here we will discuss the equipment used in welding processes and their maintenance.
Since the equipment used in the resistance welding process is relatively expensive, all of its parts require regular inspection and care at various intervals such as weekly, monthly or yearly, depending on many factors.
Resistance welding requires regular maintenance of some equipment, such as timers, switches, motors, contactors, electrodes and holders, cooling and air systems, clamps, and hydraulic fittings, welder exteriors, etc.
Maintenance program for Resistance welding
- Clean electrode holder, clamps and exterior of the welder, use carbon tetrachloride for machine cleaning; it does not attack copper. Avoid using gasoline.
- Do not allow dirt to accumulate in the transformer, this may cause serious burns. Use the low pressure (25psi or less) air duct of a vacuum cleaner.
- Footswitch, tube sockets, cables and ventilating screens should be checked and cleaned on monthly basis.
- The flush cooling system should be reversed once a month to wash out dirt and rust particles.
- Inspection of water hoses and connections for rust and other damage should be carried out quarterly.
- Water hoses must be inspected and connections for corrosion and another damage quarterly.
- If needed, run a test on a sequence timer with an oscilloscope or cycle recorder, recalibrating unit.
- The air system should be checked for any leaks, such as faulty regulation valves and controls.
- Check for excess wear in all moving parts of the machine.
- Clean transformer, replace water and air hoses if required.
The maintenance program followed here depends on the type of transformer or D.C motor-generator.
- Lubricate the bearings and other moving parts if, using a DC inductor-generator.
- Check the brushes for wear and, instead of short brushes, fitting them into the commutator contour. If not, there is a possibility that the commutator may be damaged.
- Electrode holders, welding cables and ground connections should be checked properly.
- Check the bearings for hover-heating during operation, if the bearing is overheated, take it out and replace it.
- Brushes and spring should be checked.
- Blow out the transformer with a low-pressure blower.
- Use a blower to clean the transformer with low pressure (25 psi) air duct.
- Transformer supporting bolts and loose electrical connections should be tightened properly.
- Check the ventilating fan and clean if it is required.
- Examine condensers, baked units, or those that extract dielectric oil and must be replaced.
- Check condensers. Buckled units or those that exude dielectric oil are blown and must be replaced.
- Loose electrical connections and supporting bolts should be tightened.
- All electrical connections should be checked for any defects.
- All moveable part of the machine and bearings should be clean and re-lubricated.
- Blow out a transformer or generator armature and field coil, mother coil, rotor and stator coil and clean it properly.
However, these recommendations are general and may not include specific practices favouring the manufacture of some machines, but as a general guide, these recommendations can be used and improved performance can be ensured.
Maintenance of these units requires more care than the other types as a serious problem can arise from the pressure parts being damaged. Some of the main measures for this are as follows:
- Pressure regulator, flash arrestor, hose pipe, should be checked on daily basis.
- Oxygen and acetylene shutoff valves should be checked for any leakage daily.
- Inspect gas piping and manifolds, if using.
- Avoid using lubricant in regulators in any way to connect cylinders.
- Apply the solution to suspected leak on daily.
- Check blowpipe tips for carbon or slag.
- Check the hose pipe for any leakage.
- The ventilator intake pipe should be free from any obstructions.
All pressure gauges and regulators should be checked.
Twice a year
Check the suction tube or hood supports and structure for any defects.
Check the complete ventilation system
Conclusion: A good welding maintenance program is helpful in keeping the plant top notch.
Protective tools for gas welding operation