Welder performance qualifications, Mechanical Engineering

Assignment Help:

WELDER PERFORMANCE QUALIFICATIONS


Requirement of Welder Qualification

In performance qualification, the basic attempt is to establish the ability of the welder to deposit sound metal. In case of welding operator qualification it is his mechanical ability to operate the welding machine that is tested and acknowledged.

During welder's qualification, only the essential variables (as applicable to welder's skill) are considered and production welds with such altered variables should not be continued without additionally qualifying the welders. A welding machine operator usually gets qualified along with procedure test. Additional qualifications are to be suitably enforced as and when certain essential variables are not meeting.

Codes for Performance Qualifications and Acceptance of Defects


A large number of industrial codes now a days recognise prequalified welding procedures as t he manufacturing firms are able to produce the documentary evidence for such procedures as in vogue in their organisations. The selection, training and qualification of welders are the next few steps. Some of the popular codes to look for, at this juncture are:

  • Indian Boiler Regulations - IBR
  • ASME Boiler and Pressure Vessel Code - Section IX (Welding, Brazing & Soldering Qualifications)
  • DIN 8560 - (Testing of Welders)
  • BS 4872 - (Approval Testing of Welders when welding procedure approval is not required.
  • ISO
  • EN

 


There are also number of other specifications for welder testing, pertaining to individual codes of construction. A welder's plate test coupon can be maximum 300 mm x 400 mm with appropriate thickness to cover the allowed, specified thickness ranges. Similarly 2 pipes (or tubes) having a maximum of 125 mm length each are joined together for a pipe weld test coupon.

The test coupons are then subjected to radiography testing. Welders are outrightly failed for the following indications in the radiographic film. All other defects are acceptable within limits.

1. Severe root porosites / blow holes
2. Cluster of porosites
3. Cracks
4. Lack of fusion / incomplete penetration

After necessary post weld heat treatment the plates or pipes are marked, stamped, cut and machined into mechanical test specimens. Though, the requirements of the codes are slightly varied, 2 face bend tests and 2 root bend t ests alone are conducted for performance qualifications. In lieu of the above a radiographic evaluation is done.


Related Discussions:- Welder performance qualifications

Diesel cycle, The pressure and temperature of a diesel cycle at the start a...

The pressure and temperature of a diesel cycle at the start are 1 bar and 20C respectively and the compression ratio is 14. The pressure at the end of expansions 2.5 bar. Find perc

Describe the extrution process, Q. Describe the extrution process? The ...

Q. Describe the extrution process? The extrusion process, in many cases produces material in an intermediate form for subsequent reprocessing to its final component form. The p

Leak repair torquing procedure, Q. Leak Repair Torquing Procedure? Atte...

Q. Leak Repair Torquing Procedure? Attempt to tighten only the bolts contained within an arc that includes the leak area plus one or two bolts either side of the leak to the or

Computer aided analysis, This components extensively used teh specialized ...

This components extensively used teh specialized and / or general purpose software. Often it may development for typical application and to perform calculations in the design

Explain about nonconforming material, Q. Explain about Nonconforming Materi...

Q. Explain about Nonconforming Material? If PMI test results indicate that the material or item does not meet the specified composition of the alloy, the subject material/item

Calculate values of ki - thick cylinder, Calculate values of KI - thick cyl...

Calculate values of KI - thick cylinder: If cracks of 6 mm and 12 mm length are separately present only one side of inner surface in radial direction find two values of KI.

What do you mean by forging, With the help of neat diagrams show various ro...

With the help of neat diagrams show various roll arrangement used in rolling mills. What do you mean by forging? With the help of a diagram differentiate between press forging and

Section modulus and value of bending moment, Q. Wha t do you mean by secti...

Q. Wha t do you mean by section modulus ( Z )? What is value of bending moment in the terms of section modulus? Sol.: Section modulus is ratio of M.I. about neutral ax

Steam engine terminology, STEA M ENGINE TERMINOLOGY: 1 .     Cylind...

STEA M ENGINE TERMINOLOGY: 1 .     Cylinder Bore: Inside diameter of cylinder. 2 .     Cover End and Crank End of cylinder: In the horizontal cylinders the end that

Preliminary stress analysis, Preliminary stress analysis work will start ea...

Preliminary stress analysis work will start early in the detail engineering phase after completion of equipment layout and piping study drawings. The piping required to be analyzed

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd