🔧 How Do I Qualify a Welding Procedure? (WPS Process Step by Step)
As a mechanical engineer working in pipe manufacturing, qualifying a welding procedure is not just a technical task — it’s a guarantee of quality and safety.
Here’s how to from a concept to a qualified WPS 👇
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1. Start with a pWPS (Preliminary Welding Procedure Specification):
I prepare a draft based on project specs and the applicable standard (e.g., API 5L or ASME IX).
It includes:
" Welding process: SAW / GMAW / SMAW
" Joint type & groove design
" Base metal grade
" Filler wire & flux
" Preheat & interpass temperatures
" Welding positions and passes
" Voltage, amperage, travel speed
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2. Perform the Welding Trial:
Using the pWPS, we weld a test coupon under controlled conditions.
All parameters are monitored and recorded carefully.
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3. Non-Destructive Testing (NDT):
Before we cut the coupon, we apply:
" Visual Inspection (VT)
" Ultrasonic Testing (UT) or Radiography (RT)
This ensures surface and internal weld soundness.
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4. Destructive Testing (DT):
We cut and test the coupon to verify:
" Tensile strength
" Bend test
" Impact test (for PSL 2 or low-temperature service)
" Macro/micro examination
" Hardness test (if required)
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5. Issue PQR (Procedure Qualification Record):
If all results meet the code and project requirements, we record them in the PQR, which validates the process.
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6. Final WPS Approval:
Based on the PQR, the Welding Procedure Specification (WPS) is issued and approved for production use.
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This cycle ensures that every weld meets performance expectations before it even reaches the field.