Guide to PVDF IR Welding: Parameters, Bead Quality, and Qualification

What factors can influence the appearance of infrared welding bead size?

Environmental temperature, air movement, pipe/fitting temperature, quantity of joints, MFR, misalignment, removed endcaps, and machine tolerances.

What is the maximum acceptable misalignment of components during welding?

Less than 10% of the wall thickness.

When should endcaps be removed during the welding process?

Only after the cooling time is finished.

What does MFR stand for in the context of PVDF welding?

Melt Flow Rate.

How does the MFR of injection molded fittings compare to extruded pipes?

Injection molded fittings melt easier and faster than extruded pipes.

What is the minimum bead size (b1) requirement for pipe-to-pipe or pipe-to-fitting welds?

b1 must be greater than or equal to 0.5.

What is the minimum bead size (b1) requirement for machined fitting welds?

b1 must be greater than or equal to 0.4.

What is the typical ambient temperature range for PVDF IR-welding?

+10 °C to +40 °C.

What should be done if a weld is marked as 'NOT OK'?

It must be cut out or removed.

What is the significance of the bead shape in PVDF IR-welds?

The bead shape must conform to specific guidelines to ensure weld integrity.

What is the maximum allowable depth for marginal notches on the component's surface?

Notches deeper than 10% of the nominal wall thickness are acceptable.

What does the error code '28' signify in the welding process?

Error heating element temperature.

What is the responsibility of the welder regarding the weld?

The welder must evaluate the weld and its suitability for the intended purpose.

What is the maximum size of bubbles allowed in the IR-weld bead?

Bubbles are acceptable if they are not within the wall thickness.

What does the term 'bead size' refer to in PVDF welding?

The width and shape of the weld bead formed during the welding process.

What is the bead rating criteria based on?

Internal and external testing of PVDF IR welds.

What is the minimum bead size for SDR 21 AGRU PVDF piping system?

b1 ≥ 0.5 for pipe-to-pipe and pipe-to-fitting, b1 ≥ 0.4 for machined fittings.

What should be done after the visual check of the weld bead?

A label with joint information must be printed and placed next to the weld.

What is the significance of the AGRU guidelines?

They provide standards for the qualification and evaluation of PVDF IR-welds.

What is the maximum bead size for a pipe diameter of 63 mm in SDR 21?

b max. is 9.5 mm and b min. is 3.4 mm.

What is the acceptable limit for welding flash notches?

Welding flash notches are not permitted (k > 0).

What is the bead size requirement for machined fitting-to-pipe welds?

b1 must be greater than or equal to 0.4.

What does the term 'bead shape evaluation' refer to?

The assessment of the weld bead's dimensions and integrity.

What is the maximum depth of marginal notches allowed?

Notches must not exceed 10% of the nominal wall thickness.

What happens if the welding error is not resolved before repeating the weld?

The same error may occur again, leading to further issues.

What is the purpose of the AGRU Bead Rating Criteria?

To ensure quality and consistency in PVDF IR welds.