What is Welding Procedure Specification (WPS)?


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What is WPS?

Welding Procedure Specification or WPS is a document used to describe the welding process. The document contains a welder’s instructions to manufacture quality welding as required.

The Contract Documents must require the presence of the Welding Procedure Specifications (WPS) for each welding carried out in the project.

The WPS should be reviewed by an engineer and the WPSs should also be distributed to the Inspectors responsible for welding inspection.

WPS must contain all variables (essential, nonessential, and supplementary essential) that are used in the welding process and must refer to the Procedure Qualification Record (PQR). With the support of PQR changes are made to the essential variables in the initial WPS.

Procedure Qualification Record:

The PQR is a record of variables recorded when the test coupons are welded. It also includes the test results of the specimens tested. Recorded variables are the actual variables used in manufacturing welding.

The completed PQR shall document all essential and, if necessary, additional essential variables for each welding process used during the test coupon welding.

Contents of WPS:

The information provided in the WPS must be sufficiently detailed so that the welding carried out will meet the required code, standard, or specifications. And all these details must be clear and can be followed by welder and welding operators without experiencing difficulties.

Download WPS model: Welding-Procedure-Specification-Structural.pdf (65.7 KB)

Items listed in a WPS:

  • Scope
  • Base Metal
  • Welding Processes
  • Type, Classification, Composition of filler Metals
  • Type of Current and Current Range
  • Arc Voltage and Travel Speed
  • Joint Design and Tolerances
  • Joint Preparation and Cleaning of surfaces for Welding
  • Joint Welding Details
  • Position of Welding
  • Preheat and Interpass Temperature
  • Root Preparation Prior to Welding from second Side
  • Peening
  • Removal of Weld Section for Repair
  • Repair Welding
  • Post Weld Heat Treatment
  • Tack Welding

List of Welding process and their designation:

  • Shielded Metal Arc Welding - SMAW

  • Gas Metal Arc Welding - GMAW

  • Flux Cored Arc Welding - FCAW

  • Metal Cored Arc Welding - MCAW

  • Gas Tungsten Arc Welding - GTAW

  • Submerged Arc Welding - SAW

  • Plasma Arc Welding - PAW

  • Electroslag Welding - ESW

  • Electrogas Welding - EGW

  • Stud Welding - SW