Page 149 - CITS - Welder - Trade Theory

WELDER - CITS

Lesson 46 - 48 : Requirement for qualification in different

codes Qualification procedure under

various codes Different tests and

inspection involved in qualification

Pressure welding codes and standards
(IBR, ASME etc.) Writing procedure for

WPS and PQRs

Objectives

At the end of this lesson you shall be able to
• describe the welding, qualification and code
• explain the welder performance qualification
• explain the weld procedure specification.

Welding procedure, Performance, Qualification and codes
Introduction
Code’ is any set of standards set forth and enforced by a local government for the protection of public safety,
health etc.. as in the structural safety of building, (building code) health requirements for plumbing, ventilation
etc.... (Sanitary or health code) and the specifications for fire escapes or exits (Fire code) ‘Standard’ is defined as
‘something considered by an authority or by general consent as a basis of comparison, an approved model’. As a
practical matter, codes tell the user what to do and when and under what circumstances to do it. Codes often legal
requirements that are adopted by local jurisdictions that then enforce their provisions. Standards tell the user how
to do it and are usually regarded only as recommendations that do not have the force of law. The uses of welding
in Engineering Industries are Boilers, Heat Exchangers, Pressure Vessels, Bridges, Ships, Pipelines, Reactors,
Storage tanks, Construction Structures and Equipment etc. When a design engineers designs a welding structure,
the function of production & Quality control personnel is to translate that design in to a real component. From a
design point of view properties of the weld joint are designed as-
1 Physical soundness (free from discontinuities)
2 Related Theory for Exercise 2.6.06 Metallurgical compatibility (Chemistry of weldment, base metal, gas etc.)
3 Mechanical Properties The welding Procedure Specification (WPS) is written exactly to translate these property
requirements on to relevant welding variables.
The procedure has to be testified on a test piece for its intended performance by a qualified welder. To draw a
correct weld procedure, performance methods and qualification criteria, there are popular codes and standards
are available. All the codes specifies the rules for the preparation of welding procedures specification and the
qualification of welding procedures, welders and welding operators. This code specifies the rules for all manual
and machine welding processes. Reading of Welding Procedure specifications (WPS) & Reading of Procedure
Qualification Record (PQR) Government as well as private organizations develop and issue standards that apply
to a particular area of interest. Many standards with regard to the welding industry are prepared by the American
Welding Society (AWS). Many countries have their own national standards on the subject of welding. The following
are examples of the various standards, and the bodies responsible for them.
There is also the International Organization for Standardization (ISO). The main goal of ISO is to establish uniform
standards for use in international trade. The American Welding Society publishes numerous documents on welding
and some of them are listed below:
Welding procedure qualification: A welding procedure qualification is the test to prove that the properties of a
weld to withstand the service conditions as designed for particular/specific purpose.
Welder performance qualification : A welder’s performance qualification is the test to certify a welder’s or a
welding operator’s ability to deliver consistently quality welds. This performance qualification is always done in
accordance with a qualified weld procedure specification.

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