Welder performance qualifications, Mechanical Engineering

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.

Posted Date: 9/18/2012 1:45:45 AM | Location : United States







Related Discussions:- Welder performance qualifications, Assignment Help, Ask Question on Welder performance qualifications, Get Answer, Expert's Help, Welder performance qualifications Discussions

Write discussion on Welder performance qualifications
Your posts are moderated
Related Questions
Standard for Exchange and Transfer (SET) The interface SET is a standard for the exchange of all data which is generated for CAD/CAM. It is a French development and was first p

what is the relation ship between tolrancr grade and manufacturing process ?

Calculate the length of plastic deformation: Calculate the length of plastic deformation along 45o in case the applied stress is 63.25% of yield stress in the plate of abov

Define rpm

Determine  forces in members of cantilever truss: Determine  forces  in  members   B C   and  BD   of   cantilever truss  shown  in  the figure in the figure given below.

Illustrate governing Mechanism of Francis turbine.

Q. Steam Generator Master Pressure Control? The combined header pressure is controlled by a regular P.I.D. controller which ultimately trims the water flow to each boiler. A

EXPLAIN THE COMPOUND BELT DRIVES

Derive steady flow energy equation?Also give applications of steady of steady flow energy mathematical equation?

Once vendor drawings are received and piping isometric drawings are prepared, the Mechanical engineer will provide a final stress package to the stress engineer per The stress a