WPQR range of qualification to EN ISO 15614-1
Enter the test piece data and the calculator shows what the WPQR covers: thickness, diameter, positions, heat input, preheat and interpass temperature. Level 2 is calculated — the familiar ISO 15614-1 ranges.
Short answer
One test piece does not qualify one thickness; it qualifies a range around it. A multi-run weld on a 12 mm test piece covers 6–24 mm, and a 114.3 mm pipe covers everything from 57 mm upwards. That is why the test piece is chosen not for ease but for the range it buys. The calculator below gives that range for level 2 of EN ISO 15614-1.
Level 1 and level 2
The 2017 edition introduced two levels of qualification. Level 2 carries the earlier ISO 15614-1 ranges — they did not change, and existing records stayed valid. Level 1 is built on ASME IX and asks for less: it appeared for shops working to EN 1090 execution class EXC2 and on lightly loaded structures, where the full test programme cost more than the work justified.
There is a direction between the levels: a level 2 record also serves level 1 work, but not the other way round. The calculator works out level 2; level 1 has its own table taken from a different code, and one cannot stand in for the other.
The material group coverage to ISO/TR 15608. That table was reworked in 2017 more than the others, and its “parent material 1 — parent material 2” matrix reads ambiguously in secondary sources; putting a plausible-looking figure here would mean deciding on the inspector’s behalf. The principle is set out below in words, and a particular pair belongs in the standard itself.
Level 1 is left out too: it has its own ranges, and mixing them with level 2 in one document is not allowed.
Rules worth remembering
Positions. As long as there are no impact or hardness requirements, one position covers them all — the position simply is not an essential variable. The moment impact testing is required, the positions covered are those with the same or lower heat input; for hardness it is the reverse, the same or higher. If both a high and a low heat input position were tested, everything between them is covered.
Heat input. With an impact requirement it is capped from above: no more than +25 % of the tested value. With a hardness requirement it is held from below: no less than −25 %. The logic is simple — overheating ruins toughness, and cooling too fast raises hardness.
Material groups. In groups 1 to 3 the sub-groups are not counted: the steels covered are those of the same main group with equal or lower specified yield strength. In the other groups it is the same sub-group, sometimes together with the lower ones. A test on 304, for example, covers 316, 347 and 321, but neither 309 nor 310.
Where the values come from
The thickness table, the position rules and the heat input tolerance come from the open review of EN ISO 15614-1 on gowelding.com; the 2017 changes (the “test piece up to 3 mm” row, preheat and interpass) from the review on weldnote.com; the position rule is confirmed by TWI material, and the “plate qualifies pipe” rule by the Polish wikiweld. The links are collected at the end of the page.
I do not hold the standard itself, and that is said plainly: the values are for guidance, and its text together with your own record settles any dispute.
Sources
- gowelding.com — European Welding Standards (PDF)
- weldnote.com — ISO 15614-1 (2017): Changes and Updates
- TWI — Weld Procedure and Welder Qualifications (PDF)
- wikiweld.pl — Zakres kwalifikowania technologii EN ISO 15614-1
Frequently asked questions
Which level should I go for, one or two?
Level two is stricter and covers both kinds of work; level one is cheaper and enough where the structure is lightly loaded and the client asks for no more. Convenience does not decide it — the order specification does: if that names level 2, level 1 will not do under any circumstances.
Why are the material groups not calculated?
Because their table was rewritten in 2017, and the matrix cannot be reconstructed from summaries without risking a mistake on some pair of steels. The general rule is given on this page, but a particular pair needs the text of the standard: this is exactly the case where a guess costs more than fetching the document.
Why does one position cover all of them?
Because without impact or hardness requirements the position does not affect what the test proves. As soon as those requirements appear the position starts to matter a great deal — through the heat input — and the range narrows to the positions with a suitable one.
What did the 2017 edition change about preheat?
The preheat used on the test piece used to become the lower limit literally: nothing below it. A 50 °C reduction on the WPS is now permitted. The interpass temperature got a symmetrical +50 °C, but not for austenitic and duplex steels or nickel alloys — there it stays as it was on the test piece.
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