🔧 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 👇

⸻

✅ 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

⸻

2. Perform the Welding Trial:

Using the pWPS, we weld a test coupon under controlled conditions.

All parameters are monitored and recorded carefully.

⸻

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.

⸻

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)

⸻

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.

⸻

6. Final WPS Approval:

Based on the PQR, the Welding Procedure Specification (WPS) is issued and approved for production use.

⸻

This cycle ensures that every weld meets performance expectations before it even reaches the field.