Product Update -  CHOPREC 401
SELECTING THE RIGHT WELDING & CUTTING EQUIPMENT
 
INTRODUCTION
It is very important to select the right welding process and equipment for a fabrication job. Selection of either inappropriate welding process or equipment leads to quality problems and at times to rework / delays which reduce productivity. This assumes greater importance because of multiple choices available due to technological advancements. The selected welding process and equipment influence the overall welding cost of a fabricated structure. This mailer provides guidelines to select the right welding and cutting equipment for a given application.
 
IMPORTANT CRITERIA FOR SELECTION OF WELDING AND CUTTING EQUIPMENTS
As mentioned above, multiple choices of technology are available for welding a given structure or job.  In general, following important criteria should be considered while selecting equipment for “best fit solution”.
  • Study of applications
  • Arc welding process selection
  • Equipment type/technology type available
  • Environment and field or site conditions
  • Duty cycle at which equipment is proposed to be used
  • Enclosure/ protection desired
  • Class of insulation required
  • Input supply conditions and electrical protections required thereof
  • Maintenance of equipment/ availability of service
  • Availability of equipment with special features
 
STUDY OF APPLICATIONS
Before selecting welding equipment, particularly for projects where large number of equipment will be required, it is always better to study the applications to understand following:
  • Types of welding processes to be used at a particular site
  • Are the welding processes and parameters accurately defined in the drawings and WPS/PQR established?
  • Productivity level, project completion time schedules etc.
  • Use of conventional or new technology -energy efficient equipment
  • Indoor or outdoor use
  • Whether equipment are to be used for a specific project and shall be disposed off subsequently once the project is over
  • Criticality of application and any specific requirement / approval from customer’s customer or third party/inspection agency required
  • Specific delivery schedules, demonstration of equipment etc required, as applicable.
  • Costing budget.
Analysis of above will help select optimum solution of equipment for the given application     
 
SELECTION OF RIGHT ARC WELDING PROCESS
Different metals can be joined by one or more welding processes. Also different welding processes require different skill levels from welder. Therefore, as a first step, select the process for a given metal to be joined from the table given below:
Welding Process
Cutting Process
Metal
Type
Stick
MIG
FCAW
SAW
AC-
TIG
DC-
TIG
CAC
-A-AC
CAC
-A-DC
Plasma
Steel
Stainless Steel
Aluminium
Cast Iron
Copper, Brass
Titanium
Magnesium Alloys
Skill Level
Moderate
Low
Low
Moderate
High
High
Moderate
Moderate
High
(CAC-A-AC=Carbon Arc Cutting with AC power, CAC-A- DC= Carbon Arc Cutting with DC power)
 
As mentioned, more than one welding process can be used for a given requirement. The advantages and the merits of various processes are given below which will help select right process for the given application.
 

A

SMAW/MMAW /
STICK WELDING
Most suitable for outside/open door use
One of jobs or relatively less volume jobs
Better accessibility for intricate joints
Ideal for dirty/rusty surfaces

B

GMAW/MIG/MAG CONTINUOUS WELDING
Suitable for high welding productivity
Most suitable for relatively thinner sheets
Very neat and clean welding without slag removable
Easy to learn for welders

C

FLUX CORED (FCAW)MIG/MAG
Suitable for deep penetration for welding thick sections with less nos. of runs
Provides higher welding deposition rates
Gives excellent weld bead shape

D

SUBMERGED ARC WELDING (SAW)
Most suitable where excellent mechanical properties are required
Suitable for heavy duty longitudinal structures like girders
High deposition rates gives higher welding productivity
Gives excellent weld bead shape

E

TIG WELDING
(GTAW)
Used where highest quality welding required
Gives precise welding with very good welding finish
Most suitable for thinnest sheets where better heat input controls are required and very minimal distortion allowed

F

PLASMA ARC CUTTING
Used with almost all electrical conducting metals
Distortion free, dross free, burr free, narrow kerf with clean cuts, compared to carbon arc cutting

G

AIR CARBON ARC CUTTING
(CAC) AC & DC
Cutting operation is performed by the arc generated between Carbon or graphite electrode and the base metal with adequate air flow to remove the metal
Used to remove metal from defective weld area
 
SELECTING WELDING EQUIPMENT OF RIGHT TECHNOLOGY
Inverter or Chopper type power sources have a power factor about 0.92 and efficiency more than 85%. The energy cost for using these types of welding power sources will be much lower than the transformers and diode type rectifiers as illustrated in the table given below. Apart from the lower energy bill, welding performance also improves with the use of Inverters or Chopper based power sources, since spatter level is much lesser with these power sources.
 
Inverter based/Chopper based 400A Rectifier, Electrode -5.0 mm, and Weld current – 200A
Parameter
Diode based
Thyristor based
Inverter based
Chopper based
Weld current 
200
200
200
200
Input Current
27.0
21.5
11.4
11.5
Input KVA
18.8
15.5
8.40
8..6
Input KW
10.0
9.0
7.0
7.2
Power factor
0.53
0.58
0.84
0.84
Efficiency %
60
70
85
84
ENVIRONMENT AND SITE CONDITIONS
Welding equipments are designed for operation at 40 Degree Celsius ambient temperature and at 1000mtr altitude as per international standards. For applications at higher temperature and higher altitudes, these machines are to be suitably derated in consultation with equipment manufacturers, since ventilation gets affected at higher temperatures as well as at higher altitudes.
If ventilating air is very salty or corrosive or contaminated with acidic fumes, dust/dirt etc, then windings should be protected with additional layer of resin impregnation and printed circuit boards should be epoxy coated to protect them against corrosion etc. The terminal connectors should be suitably treated and sealed so that they do not get short circuited due to dust/dirt and do not get open circuited due to corrosion or oxide formation at contact pins.
Site conditions should be studied and recommendations should be made to ensure satisfactory performance of welding equipment.
 
SELECTION OF EQUIPMENT FOR DIFFERENT DUTY CYCLES AND LOAD CONDITIONS
Following guidelines can be observed for the selection of equipment based on their expected workload.
 
Duty Symbol
Workload/Usage / Duty
Likely Duty cycle
Welding current Range Recommended
L
Light Duty
Single shift
20% to 35 % Up to 225 Amps
M
Medium Duty
Single or Two Shift
>35% to 60% 225 Amps to 300 Amps
H
Heavy Duty
Two or Three shift
> 60% to 100% More than 300 Amps
 
DEGREE OF PROTECTION FOR ENCLOSURE OF WELDING MACHINE
The degree of protections offered by the enclosure is indicated by letters IP21, IP22, IP23, IP44 etc. The letter IP means International Protection class; the first digit of suffix indicates protection against the ingress of foreign body (2 indicates the body size 12 mm or more, 4 indicates the body size between 1mm and 12 mm dia); second digit indicates protection against ingress of splashing rain water (1 indicates splashing water up to 15 degrees from vertical plane and 3 indicates up to 60 degrees from vertical plane and 4 indicates all around the machines). IP23 and IP44 are recommended for machines for outdoor use where as IP21 & IP23 are recommended for machines for internal or shop floor use.
 
CLASS OF INSULATION OF WELDING MACHINES
 Insulation class F withstands temperature up to 155 degree Celsius and insulation class H withstands temperature up to 180 degree Celsius. Insulation class H should be recommended for machine for higher ambient temperatures and where machine is likely to be used at higher welding currents.  Normally welding machine with H insulation class is more reliable in difficult or worst ambient conditions.
 
INPUT SUPPLY CONDITIONS AND ELECTRICAL PROTECTION
Welding equipments are used within the shop floor as well as at project sites. Welding equipment need to be protected against extreme over voltage, under voltage, and voltage/current spikes. User must therefore, make sure that such protections are provided on the machines to avoid frequent breakdowns of machines due to erratic input supply conditions. Apart from under and over voltage protections, machine should be provided with single phase, over load and over heating protections to prevent overloads and avoid  breakdown and loss of productive time.
 
MAINTENANCE/ AVAILABILITY OF AFTER SALES SERVICE
Often equipment is sent to different sites on specific requirements. Users must check availability of service from manufacturer at these locations to ensure minimum downtime.
 
AVAILABILITY OF EQUIPMENT WITH SPECIAL FEATURES
Welding equipments with following additional features are available and can be selected where essential
  • Power sources with built in Energy Saving Devices (ESD)
  • Power source with Arc On time measurement/indication (ARCON)
  • Voltage Reducing Devices (VRD), where output voltage is reduced to a safe limit when power source is not in use
  • Ventilation or  air suction to the power source, only when required
  • Use of multiple wires simultaneously to improve the productivity
  • Welding Payloads for simultaneous use by 2 /4/6/8 or more welders
 
CONCLUSION
The user will be benefited by going through the above criteria for selecting right equipment to improve welding productivity.

Ador Welding Ltd. offers a wide range of welding and cutting equipment for these processes. Please click on the name of equipment to view detailed specifications:
Welding Process Transformer
 AC power sources
Diode based DC power sources Thyristor based
DC power sources
Inverter based DC power sources Chopper based DC power sources
SMAW E Welmac 150
E Welmac 190

DM 250
DR 300
DH 400
DS 500

RED 403/503
TPA 303/403
GL 401
GL 601
Silent Challenger 301
Silent Challenger 401
Silent Challenger 501
Thyroluxe 401
Thyroluxe 500
Thyroluxe 600
Champ 150
Champ 163
Champ 253

Champ 400
Champ 600
Choprec 401
Silent Challenger 2x300
GMAW /
FCAW
MULTI
  Maximig 251/400
Automig 250/400
Ranger 400/403
Ranger 503/600
Ranger Multi 600
Champ Multi 400
Champ Multi 400 (SSPW)
Silent Challenger Multi 2x301
GTAW RED 403
RED 503

HF 2000AD
HF 3000AD
GL 401
GL 501
HF 2000/AD
HF 3000/AD
Thyroluxe 401
Thyroluxe 500
Thyroluxe 600
HF 3000
Champ Tig 163/303, 300AD
303AD
 
SAW   Maestro 600/800/
1000/1200
Maestro  600/800/ 1000/1200(T) Maestro 1000 (i)  
AIR PLASMA
CUTNG
  Plasma cut 25   Champ cut 8
Champ cut 25
 
 
Please contact cmo@adorians.com for advice on selecting welding process and equipment to improve weld quality and productivity while reducing downtime and rework.
CHPREC 401
Faster response time through 40 Khz switching frequency circuits resulting superior welding
Improvement in the protection circuits for superior fool proofing against failures
Improving reliability of key components by a factor of 4 over previous generation which has been done in consultation with component manufactures
RANGER 400 / 600
RANGER 400 / 600
Sturdy, compact and 100% dependable, portable power source
A wirefeeder half the normal weight of the conventional one,, minimizes welder fatigue
Added operator safety because of low voltage supply to wirefeeder from the source
MAESTRO SERIES
MAESTRO SERIES
Choice of Boom mounted or Tractor mounted models with Diode / Thyristorised Power Source
Bcom mounted head comes with a choice of manual, semi-motorised and fully motorised cross slides
Programmed sequential operations of Power Source, Wire Feed and Carriage through built-in solid state circuitry
SILENT CHALLENGER MULTI 2 x 301
SILENT CHALLENGER MULTI 2 x 301
India's First Silent Double Operator Welding Set with Multi Process Welding Capabilities and Confirming to Latest CPCB Norms for Noise and Emission Level
Highly Reliable even in Hostile Site Conditions
ADOR Institute of
Welding Technology
Ador Institute of Welding Technology
 
Refresher Course in
Welding Technology (SC-1)
2nd - 7th August 2010
 
Course for
Welding Procedures &
Qualifications (QA-2)
16th - 18th August 2010
 
Certification Course for
Welding Inspector (QC-1)
4th - 9th Oct. 2010
 
Course for Quality Assurance
& Control of Welding (QA-1)
11th - 14th Oct. 2010
 
Hands on training for
Welders / Operators
 
Project Engineering
Solutions
ADOR Institute of
Welding Technology
Welding &
Cutting Solutions
Centre for
Engineering Excellence
Ador Welding Limited - Welders To The Nation
www.adorwelding.com
cmo@adorians.com Contact us