You might be asking, what is P-Numbers? P-Number is often used in WPS and Welder’s Qualification.
In accordance to QW-420.1 of ASME IX, to reduce the numbers of welding and brazing procedure qualification required, base metals have been assigned P-Numbers, and for ferrous base metals which have specified impact test requirements, Group Numbers within P-Numbers. These assignments are based essentially on comparable base metal characteristics, such as composition, weldability, brazeability and mechanical properties, where this can logically be done. These assignments do not imply that base metal maybe indiscriminately substituted for a base metal which was used in the qualification test without consideration of compatability from the stand point of metallurgical properties, and service requirements. Where notch-toughness is a consideration, it is presupposed that the base metals meet the specific requirements.
The P-Numbers of each specific materials are listed in QW/QB-422 of ASME IX.
Saturday, December 20, 2008
Tuesday, December 2, 2008
CODES AND STANDARDS
CLASS OF WORK
There are many types of work which require engineering materials to be joined by welding, for example:
Pressure vessels
Bridges
Oil rigs
Earth moving equipment
Aero-engines
Ventilation systems
Storage tanks
Heavy vehicle chassis
Car bodies
Food processing plant
The quality requirements of the joints in these fabrications depend on their fitness-for-purpose and differ significantly from one application to the next. Pressure vessels require welds, which can withstand the stresses and high temperatures experienced in operation. Oilrigs are designed to withstand the effect of wave formation and wind loads. Earth moving equipment has to accommodate differences in terrain and earth conditions and is subject to fatigue loading. Welds in food processing plants must withstand corrosion by hot acidic liquors.
Below are listed some typical codes of practice and standards which cover various types of constructions fabricated by welding.
Code----------- Class of Work
BS 5500-------- Unfired fusion welded pressure vessels
ASME VIII------ American boiler and pressure vessel code
BS 2633-------- Class 1 arc welding of ferritic steel pipe work for carrying fluids
BS 4515-------- Process of welding steel pipelines on land and offshore
BS 5950-------- Structural use of steelwork in building
AWS D1.1------- Structural welding code (American)
BS 5400-------- Steel, concrete and composite bridges
BS 6235-------- Code of practice for fixed offshore structure
API 1104------- Standard for welding pipelines and related structures
These documents can also provide a useful source of data for applications where codes do not exist. It should be remembered, however, that the principal criterion in the codes listed is the quality of the joint in relation to the service conditions. There are other applications where success is judged by different criteria, such as dimensional accuracy.
Another important consideration is controlling the cost of welding. Variations in weld times and quantities of consumables can readily result if the method of making a weld is left to the welder to decide.
The continuous and satisfactory performance of weldments made to various codes requires that specific guidelines are laid down to cover all variables. These guidelines are usually grouped under the general heading of a Weld Procedure.
CODE OF PRACTICE
A code of practice is a set of rules for manufacturing a specific product. It should contain:
Design Requirements (e.g. fit-up, preparation and type of joints)
Material (e.g. types, thickness ranges)
Manufacturer’s Working Practice
Inspection Criteria (e.g. 100% visual, percentage other NDT)
Acceptance Criteria (e.g. defect size, limits, etc.)
Welding Process (e.g. type, consumables)
Types Of Tooling (e.g. use of strongbacks)
Contractual Information
The difference between a code and a standard is that a code states how to do a specific job and does not contain all relevant information, but refers to other standards for details.
A code or standard generally mentions three parties - the customer or client, the manufacturer or producer and the inspection authority. In a code the term ‘shall’ means mandatory - must be done, and the term ‘should’ means recommended - not compulsory.
A concession is an agreement between the contracting parties to deviate from the original code requirements. (BS 5135)
There are many types of work which require engineering materials to be joined by welding, for example:
Pressure vessels
Bridges
Oil rigs
Earth moving equipment
Aero-engines
Ventilation systems
Storage tanks
Heavy vehicle chassis
Car bodies
Food processing plant
The quality requirements of the joints in these fabrications depend on their fitness-for-purpose and differ significantly from one application to the next. Pressure vessels require welds, which can withstand the stresses and high temperatures experienced in operation. Oilrigs are designed to withstand the effect of wave formation and wind loads. Earth moving equipment has to accommodate differences in terrain and earth conditions and is subject to fatigue loading. Welds in food processing plants must withstand corrosion by hot acidic liquors.
Below are listed some typical codes of practice and standards which cover various types of constructions fabricated by welding.
Code----------- Class of Work
BS 5500-------- Unfired fusion welded pressure vessels
ASME VIII------ American boiler and pressure vessel code
BS 2633-------- Class 1 arc welding of ferritic steel pipe work for carrying fluids
BS 4515-------- Process of welding steel pipelines on land and offshore
BS 5950-------- Structural use of steelwork in building
AWS D1.1------- Structural welding code (American)
BS 5400-------- Steel, concrete and composite bridges
BS 6235-------- Code of practice for fixed offshore structure
API 1104------- Standard for welding pipelines and related structures
These documents can also provide a useful source of data for applications where codes do not exist. It should be remembered, however, that the principal criterion in the codes listed is the quality of the joint in relation to the service conditions. There are other applications where success is judged by different criteria, such as dimensional accuracy.
Another important consideration is controlling the cost of welding. Variations in weld times and quantities of consumables can readily result if the method of making a weld is left to the welder to decide.
The continuous and satisfactory performance of weldments made to various codes requires that specific guidelines are laid down to cover all variables. These guidelines are usually grouped under the general heading of a Weld Procedure.
CODE OF PRACTICE
A code of practice is a set of rules for manufacturing a specific product. It should contain:
Design Requirements (e.g. fit-up, preparation and type of joints)
Material (e.g. types, thickness ranges)
Manufacturer’s Working Practice
Inspection Criteria (e.g. 100% visual, percentage other NDT)
Acceptance Criteria (e.g. defect size, limits, etc.)
Welding Process (e.g. type, consumables)
Types Of Tooling (e.g. use of strongbacks)
Contractual Information
The difference between a code and a standard is that a code states how to do a specific job and does not contain all relevant information, but refers to other standards for details.
A code or standard generally mentions three parties - the customer or client, the manufacturer or producer and the inspection authority. In a code the term ‘shall’ means mandatory - must be done, and the term ‘should’ means recommended - not compulsory.
A concession is an agreement between the contracting parties to deviate from the original code requirements. (BS 5135)
DUTIES OF A WELDING INSPECTOR
VISUAL INSPECTION
At any point in the course of welding, i.e. tacking, root pass, filler pass or capping pass, but particularly for the root and cap, a detailed inspection may be required. British Standard 5289: 1976 gives guidance on tools and responsibilities together with sketches of typical defects.
The inspector at this point must -
a)observe, identify and perhaps record (measure) the features of the weld.
b)decide whether the weld is acceptable in terms of the particular levels that are permitted; defect levels may be ‘in-house’ or national codes of practice.
When the defect size is in excess of the permitted level then either a concession must be applied for (from a competent person), or the weld rejected.
AIDS OF VISUAL INSPECTION
Illumination:Good lighting is essential.
Inspection Lenses: The magnification should not exceed 2 - 2.5 diameters. If higher magnification is required use a binocular microscope.Optical viewing can progressively develop from eyesight, to use of a hand torch and mirror, to the addition of a magnifier and light source.
In order to achieve accessibility, remote probe units are available which must have the following properties.
a)Large field of vision
b)Freedom from distortion of image
c)Accurate preservation of colour values
d)Adequacy of illumination
CODE OF PRACTICE
A code of practice for an inspection department should take the form outlined below. It is appreciated that full implementation of the code would be extremely costly and therefore it may be necessary to reduce the amount of inspection to less than is theoretically required.
The inspector should be familiar with the following:
a)All applicable documents
b)Workmanship standards
c)All phases of good workshop practice
d)Tools and measuring devices
INSPECTION BEFORE WELDING
Before Assembly:
Check * All applicable documents.
* Quality plan is authorised and endorsed with signature, date and company stamp.
* Application standard is up to date with the latest edition, revision or amendment.
* The drawings are clear, the issue number is marked and the latest revision is used.
* Welding procedure sheets (specifications) are available, have been approved and are employed in production.
* Welder qualifications with identification and range of approval are verified and that only approved welders as required are employed in production.
* Calibration certificates, material certificates (mill sheets) and consumer certificates are available and valid.
* Parent material identification is verified against documentation and markings.
* Material composition, type and condition.
* Correct methods are applied for cutting and machining.
* Identification of welding consumables such as electrodes, filler wire, fluxes, shielding and backing gases and any special requirements (e.g. drying) are met.
* Plant and equipment are in a safe condition and adequate for the job.
* Safety permits e.g. hot work permit, gas free permit, enclosed space certificate are available and valid.
After Assembly
Check * Dimensions, tolerances, preparation, fit-up and alignment are in accordance with the Approved drawings and standards.
* Tack welds, bridging pieces, clamping and type of backing - if any used are correct.
* Cleanliness of work area is maintained.
* Preheat in accordance with procedure.
NOTE Good inspection prior to welding can eliminate conditions that lead to the formation of defects.
INSPECTION DURING WELDING
Check * The welding process must be monitored.
* Preheat and interpass temperatures must be monitored.
* Interpass cleaning - chipping, grinding, gouging, must be monitored.
* Root and subsequent run sequence.
* Essential variables such as current, voltage, travel speed to be monitored.
* Filler metals, fluxes and shielding gases are correct.
* Welding is in compliance with weld procedure sheet and application standard.
INSPECTION AFTER WELDING
Check * Visual inspection to be carried out to ascertain acceptability of appearance of welds.
* Dimensional accuracy to be ascertained.
* Conformity with drawings and standards requirements.
* Post weld heat treatment, if any, monitored and recorded.
* NDT carried out and reports assessed.
* Assess defects as to either repairing, or application for concession.
* Carry out any necessary repairs.
* Control of distortion
REPAIRS
* Repair procedure and welding code should be authorised.
* Defect area should be marked positively and clearly.
* Check when partially removed and fully removed (visual and NDT).
* Re-welding should be monitored.
* Re-inspect completed repair.
Collate all documents and reports. Pass the document package on to a higher authority for final inspection, approval and storage.
THE WELDING INSPECTOR
RESPONSIBILITIES
Ensure compliance with standard or code.
Ensure workmanship.
Ensure welding criteria by ‘policing’ work and documentation.
ATTRIBUTES
Honesty and integrity.
Literacy.
Fitness - physical and eyesight.
DUTIES
Observe.
Measure.
Identify.
At any point in the course of welding, i.e. tacking, root pass, filler pass or capping pass, but particularly for the root and cap, a detailed inspection may be required. British Standard 5289: 1976 gives guidance on tools and responsibilities together with sketches of typical defects.
The inspector at this point must -
a)observe, identify and perhaps record (measure) the features of the weld.
b)decide whether the weld is acceptable in terms of the particular levels that are permitted; defect levels may be ‘in-house’ or national codes of practice.
When the defect size is in excess of the permitted level then either a concession must be applied for (from a competent person), or the weld rejected.
AIDS OF VISUAL INSPECTION
Illumination:Good lighting is essential.
Inspection Lenses: The magnification should not exceed 2 - 2.5 diameters. If higher magnification is required use a binocular microscope.Optical viewing can progressively develop from eyesight, to use of a hand torch and mirror, to the addition of a magnifier and light source.
In order to achieve accessibility, remote probe units are available which must have the following properties.
a)Large field of vision
b)Freedom from distortion of image
c)Accurate preservation of colour values
d)Adequacy of illumination
CODE OF PRACTICE
A code of practice for an inspection department should take the form outlined below. It is appreciated that full implementation of the code would be extremely costly and therefore it may be necessary to reduce the amount of inspection to less than is theoretically required.
The inspector should be familiar with the following:
a)All applicable documents
b)Workmanship standards
c)All phases of good workshop practice
d)Tools and measuring devices
INSPECTION BEFORE WELDING
Before Assembly:
Check * All applicable documents.
* Quality plan is authorised and endorsed with signature, date and company stamp.
* Application standard is up to date with the latest edition, revision or amendment.
* The drawings are clear, the issue number is marked and the latest revision is used.
* Welding procedure sheets (specifications) are available, have been approved and are employed in production.
* Welder qualifications with identification and range of approval are verified and that only approved welders as required are employed in production.
* Calibration certificates, material certificates (mill sheets) and consumer certificates are available and valid.
* Parent material identification is verified against documentation and markings.
* Material composition, type and condition.
* Correct methods are applied for cutting and machining.
* Identification of welding consumables such as electrodes, filler wire, fluxes, shielding and backing gases and any special requirements (e.g. drying) are met.
* Plant and equipment are in a safe condition and adequate for the job.
* Safety permits e.g. hot work permit, gas free permit, enclosed space certificate are available and valid.
After Assembly
Check * Dimensions, tolerances, preparation, fit-up and alignment are in accordance with the Approved drawings and standards.
* Tack welds, bridging pieces, clamping and type of backing - if any used are correct.
* Cleanliness of work area is maintained.
* Preheat in accordance with procedure.
NOTE Good inspection prior to welding can eliminate conditions that lead to the formation of defects.
INSPECTION DURING WELDING
Check * The welding process must be monitored.
* Preheat and interpass temperatures must be monitored.
* Interpass cleaning - chipping, grinding, gouging, must be monitored.
* Root and subsequent run sequence.
* Essential variables such as current, voltage, travel speed to be monitored.
* Filler metals, fluxes and shielding gases are correct.
* Welding is in compliance with weld procedure sheet and application standard.
INSPECTION AFTER WELDING
Check * Visual inspection to be carried out to ascertain acceptability of appearance of welds.
* Dimensional accuracy to be ascertained.
* Conformity with drawings and standards requirements.
* Post weld heat treatment, if any, monitored and recorded.
* NDT carried out and reports assessed.
* Assess defects as to either repairing, or application for concession.
* Carry out any necessary repairs.
* Control of distortion
REPAIRS
* Repair procedure and welding code should be authorised.
* Defect area should be marked positively and clearly.
* Check when partially removed and fully removed (visual and NDT).
* Re-welding should be monitored.
* Re-inspect completed repair.
Collate all documents and reports. Pass the document package on to a higher authority for final inspection, approval and storage.
THE WELDING INSPECTOR
RESPONSIBILITIES
Ensure compliance with standard or code.
Ensure workmanship.
Ensure welding criteria by ‘policing’ work and documentation.
ATTRIBUTES
Honesty and integrity.
Literacy.
Fitness - physical and eyesight.
DUTIES
Observe.
Measure.
Identify.
Welder’s Test Position (ASME IX QW-461.3-461.7)
Groove Welds in Plate - Test Positions
1G, 2G, 3G & 4G
Groove Welds in Pipe - Test Positions
1G (rotated), 2G, 5G, 6G
Fillet Welds in Plate - Test Positions
1F, 2F, 3F, 4F
Fillet Welds in Pipe- Test Positions
1F (rotated), 2F, 2FR (rotated), 4F & 5F
Stud Welds - Test Positions
1S, 2S & 4S
1G, 2G, 3G & 4G
Groove Welds in Pipe - Test Positions
1G (rotated), 2G, 5G, 6G
Fillet Welds in Plate - Test Positions
1F, 2F, 3F, 4F
Fillet Welds in Pipe- Test Positions
1F (rotated), 2F, 2FR (rotated), 4F & 5F
Stud Welds - Test Positions
1S, 2S & 4S
Monday, December 1, 2008
How to Tig Weld – Basics of Tig Welding
Got a welding project to do? Need help with tig welding? Don’t worry. We’ve got some tips on how to tig weld that will save you and your welding project from disaster.
If this is your first welding project, it’s best if you get a little background information on welding first.
Welding, unlike soldering and brazing – two things that are usually mistaken to involve a similar process as welding, uses coalescence to join metals or thermoplastics.
This is done through melting the work pieces and adding another material to create a weld puddle which, when cooled, becomes a strong joint and produces the weld. So a weld, in case you’re still wondering, is simply a joint formed by welding.
To produce a good weld, first you need to make an arc. With this arc, create a weld puddle and put fill metal on it and push it along the weld joint. Finish the arc. Let the puddle cool and protect it by leaving the torch over it.
In Tig welding, it’s also important to establish a good electrical contact between the tungsten and collet. This way, current transfer and weld quality can be improved.
Practice good maintenance for your welding tools by checking them regularly for worn parts and keeping your tig torch components tightened always. You should also clean your weld joint and the filler metal by removing oil, grease, and dirt, as these elements may cause arc instability or dirty welds.
There are many books and courses that provides more tips for tig welding. Welding is both an art and a science but to achieve a perfect tig weld, you have to practice it often to get the hang of it.
By Ricky Lim
Heats School of Welding Technology, Inc. provides courses for TIG Welding as well as SMAW
If this is your first welding project, it’s best if you get a little background information on welding first.
Welding, unlike soldering and brazing – two things that are usually mistaken to involve a similar process as welding, uses coalescence to join metals or thermoplastics.
This is done through melting the work pieces and adding another material to create a weld puddle which, when cooled, becomes a strong joint and produces the weld. So a weld, in case you’re still wondering, is simply a joint formed by welding.
To produce a good weld, first you need to make an arc. With this arc, create a weld puddle and put fill metal on it and push it along the weld joint. Finish the arc. Let the puddle cool and protect it by leaving the torch over it.
In Tig welding, it’s also important to establish a good electrical contact between the tungsten and collet. This way, current transfer and weld quality can be improved.
Practice good maintenance for your welding tools by checking them regularly for worn parts and keeping your tig torch components tightened always. You should also clean your weld joint and the filler metal by removing oil, grease, and dirt, as these elements may cause arc instability or dirty welds.
There are many books and courses that provides more tips for tig welding. Welding is both an art and a science but to achieve a perfect tig weld, you have to practice it often to get the hang of it.
By Ricky Lim
Heats School of Welding Technology, Inc. provides courses for TIG Welding as well as SMAW
Sunday, November 30, 2008
70 6G WELDERS - TIG OR MIG (Urgent) for CANADA
Hey guys here's another opening for welders. Canada needs you!!! If you are qualified, please contact the agency directly. If you are not yet qualified, Heats School of Welding Technology, Inc. can help you. Enroll with us and we will train you to become a certified welder.
here the job opening......
SCS PLACEMENT SERVICES INC.
POEA License No. : POEA-162-LB-060208-R
Address : 96 New York Avenue, Cubao Quezon City Metro Manila
Tel. No. : 2 913 6104
70 6G WELDERS - TIG OR MIG (Urgent)
Work Site: Ontario, Canada
Opening Date: Nov 24, 2008 Closing Date: Dec 30, 2008
For Manpower Pooling Only. No Fees shall be collected from the Applicant.
"BEWARE OF ILLEGAL RECRUITERS"
Prospective Principal/Project Canadian Client
Proposed Salary 3,000 CAD
Qualifications Gender : Male
Age : 23 - 40 yrs old
Education : At least Vocational Diploma / Short Course Certificate
Yrs. of Experience : 2 yr(s)
1. With experience in pipe lines welding as 6G welders either in Tig or Mig process.
2. With experience in heavy industrial plant as welder.
3. With recent TESDA certification and WQT record from your previous employer.
NOTE: An applicant who does not meet the above minimum requirement, NO NEED TO APPLY PLEASE.
Please bring the following documents during the preliminary interview:
1. Updated comprehensive resume with detailed job description in every employer’s work experience. (2 sets original copies)
2. School and employment credentials including trainings and seminars attended. (2 sets xerox copies)
3. Recent passport (2 sets xerox copies)
4. Recent NBI Clearance – Travel Abroad (2 sets xerox copies)
5. 2 x 2 colored ID picture (2 pcs.)
6. Long folder with fastener (1 set)
NOTE: Only short-listed applicants will be notified for preliminary interview.
here the job opening......
SCS PLACEMENT SERVICES INC.
POEA License No. : POEA-162-LB-060208-R
Address : 96 New York Avenue, Cubao Quezon City Metro Manila
Tel. No. : 2 913 6104
70 6G WELDERS - TIG OR MIG (Urgent)
Work Site: Ontario, Canada
Opening Date: Nov 24, 2008 Closing Date: Dec 30, 2008
For Manpower Pooling Only. No Fees shall be collected from the Applicant.
"BEWARE OF ILLEGAL RECRUITERS"
Prospective Principal/Project Canadian Client
Proposed Salary 3,000 CAD
Qualifications Gender : Male
Age : 23 - 40 yrs old
Education : At least Vocational Diploma / Short Course Certificate
Yrs. of Experience : 2 yr(s)
1. With experience in pipe lines welding as 6G welders either in Tig or Mig process.
2. With experience in heavy industrial plant as welder.
3. With recent TESDA certification and WQT record from your previous employer.
NOTE: An applicant who does not meet the above minimum requirement, NO NEED TO APPLY PLEASE.
Please bring the following documents during the preliminary interview:
1. Updated comprehensive resume with detailed job description in every employer’s work experience. (2 sets original copies)
2. School and employment credentials including trainings and seminars attended. (2 sets xerox copies)
3. Recent passport (2 sets xerox copies)
4. Recent NBI Clearance – Travel Abroad (2 sets xerox copies)
5. 2 x 2 colored ID picture (2 pcs.)
6. Long folder with fastener (1 set)
NOTE: Only short-listed applicants will be notified for preliminary interview.
Learning About Welding and Necessary Supplies
Welding is an age-old process of joining metals. Welding supplies are necessary for better metal works.
The environment is a concern for all of us today. One way of saving the environment is limited use of wood in constructions, small and big. Many wood replacements were developed to imitate wood appearance. The use of metals is the more popular wood alternative.
Use of metals requires an age-old process. This is the fabrication process or the joining of materials. Welding does joining of materials, metals, or even thermoplastics. Causing coalescence joins metals. The process involves melting the pieces to be joined together and having molten filler in between to form a strong joint. Heat is used, or in combination with pressure, in producing a weld.
Welding utilizes a number of energy sources. These sources include gas flame, electric arc, laser, electron beam, friction, and ultrasound. Welding is considered as an industrial process. In spite of this thinking, welding can be done in an unlimited number of circumstances one imagines. Welding is possible in an open-air situation, underwater and yes, even in space.
Welding is dangerous, in all location where welding is possible to be done. Care must be observed when doing a welding work. Precautions should be taken into consideration to avoid unacceptable consequences such as burns, electric shock, eye damage, poisonous fumes, and overexposure to ultraviolet light.
For centuries, welding is done through the simplest process of forged welding. Heating the materials and pounding to connect metals. In this procedure, heat and pressure are used. Historic structures and art masterpieces were constructed and fabricated using this simple welding process.
Arc welding is the most popular welding process used in many work places. This is done by an electric arc between an electrode and the base materials. The metals are melted at the welding point. Electric arc is created and maintained by the use of an electric power supply. Use of an alternating or direct current and a consumable or a non-consumable electrode is possible in an electric arc welding. Shielding gas usually protect the welding area.
Arc welding requires an electrical power supply. Most commonly used are the constant current power supplies and the constant voltage power supplies. The length of the arc is directly related to the voltage while on the other hand, the amount of the heat input is related to the current. In manual arc welding, the constant current power supplies are used most often.
Power or energy supplies are the most important supplies needed in the welding processes. Another requirement in welding is a continued supply of electrodes or what is commonly referred to as welding rods. Replacement supplies for the various welding equipment and tools might be an option for a continued and uninterrupted work.
Miscellaneous supplies can be considered on hand at the work place for a better workflow. These supplies may include brushes and brooms, tape, cable ties, tie downs, tarpaulins, and vacuums.
In order that welders and assistants may perform their jobs better, supplies of these safety and comfort products may be stocked at the working area. These supplies are as follows, but not limited to the list; eye protection, face protection, gloves, first aid, protective clothing, hearing protection, respiratory protection, and other such worker comfort product.
By: Jayesh Bagde
The environment is a concern for all of us today. One way of saving the environment is limited use of wood in constructions, small and big. Many wood replacements were developed to imitate wood appearance. The use of metals is the more popular wood alternative.
Use of metals requires an age-old process. This is the fabrication process or the joining of materials. Welding does joining of materials, metals, or even thermoplastics. Causing coalescence joins metals. The process involves melting the pieces to be joined together and having molten filler in between to form a strong joint. Heat is used, or in combination with pressure, in producing a weld.
Welding utilizes a number of energy sources. These sources include gas flame, electric arc, laser, electron beam, friction, and ultrasound. Welding is considered as an industrial process. In spite of this thinking, welding can be done in an unlimited number of circumstances one imagines. Welding is possible in an open-air situation, underwater and yes, even in space.
Welding is dangerous, in all location where welding is possible to be done. Care must be observed when doing a welding work. Precautions should be taken into consideration to avoid unacceptable consequences such as burns, electric shock, eye damage, poisonous fumes, and overexposure to ultraviolet light.
For centuries, welding is done through the simplest process of forged welding. Heating the materials and pounding to connect metals. In this procedure, heat and pressure are used. Historic structures and art masterpieces were constructed and fabricated using this simple welding process.
Arc welding is the most popular welding process used in many work places. This is done by an electric arc between an electrode and the base materials. The metals are melted at the welding point. Electric arc is created and maintained by the use of an electric power supply. Use of an alternating or direct current and a consumable or a non-consumable electrode is possible in an electric arc welding. Shielding gas usually protect the welding area.
Arc welding requires an electrical power supply. Most commonly used are the constant current power supplies and the constant voltage power supplies. The length of the arc is directly related to the voltage while on the other hand, the amount of the heat input is related to the current. In manual arc welding, the constant current power supplies are used most often.
Power or energy supplies are the most important supplies needed in the welding processes. Another requirement in welding is a continued supply of electrodes or what is commonly referred to as welding rods. Replacement supplies for the various welding equipment and tools might be an option for a continued and uninterrupted work.
Miscellaneous supplies can be considered on hand at the work place for a better workflow. These supplies may include brushes and brooms, tape, cable ties, tie downs, tarpaulins, and vacuums.
In order that welders and assistants may perform their jobs better, supplies of these safety and comfort products may be stocked at the working area. These supplies are as follows, but not limited to the list; eye protection, face protection, gloves, first aid, protective clothing, hearing protection, respiratory protection, and other such worker comfort product.
By: Jayesh Bagde
Tuesday, November 25, 2008
One more Employer Looking for Fresh Graduate TIG Welder
Hey guys, one more employer si looking for fresh graduate TIG Welder.
Here is the email....
On Tue, 11/25/08, Dominic N. Chung wrote:
From: Dominic N. Chung
Subject: Inquiry for Job Hiring
To: pwtc_luzon@yahoo.com
Date: Tuesday, November 25, 2008, 3:32 AM
Dear Sir/ Madam,
We are looking for a fresh graduate who is familiar with Tig welding.
our office is here in Sta Mesa, Metro manila.
thank you and more power.
Dominic Nicandro Chung
Here is the email....
On Tue, 11/25/08, Dominic N. Chung wrote:
From: Dominic N. Chung
Subject: Inquiry for Job Hiring
To: pwtc_luzon@yahoo.com
Date: Tuesday, November 25, 2008, 3:32 AM
Dear Sir/ Madam,
We are looking for a fresh graduate who is familiar with Tig welding.
our office is here in Sta Mesa, Metro manila.
thank you and more power.
Dominic Nicandro Chung
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