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Weld map builder
Build a weld map one line at a time and watch the summary that a reviewer reads off the finished sheet: how many welds sit under each WPS, how many each welder holds, what share of the map carries an NDT method, what is still open, and whether any weld number has been claimed twice.
A line here is a run of welds that share one WPS, one welder, one NDT method and one status — the way a map is actually written on a marked-up isometric. Everything runs in your browser, and the finished sheet exports as CSV.
What the summary is counting
Welds in the map N = sum of the weld counts on the lines you filled
NDT coverage C = Nndt / N × 100, with Nndt the welds whose line carries MT, PT, RT, UT or PAUT
Margin C − Crequired, in percentage points, against the extent you type
Share of one WPS or welder n / N × 100, counted over the lines that name it
Mapped length L = sum of (welds on the line × length of each weld)
Weld numbers claimed twice the count of integers covered by two or more of the ranges [s, s + k − 1]
N = welds · k = welds on one line · s = first weld number on that line · l = length of each weld
There is no coefficient to source here and no table to look up: the summary is counting, and the only constants involved are exact unit conversions — one metre is a thousand millimetres, and one foot is 0.3048 metres by definition. That is deliberate. Sampling extents, acceptance classes and the rules for which joints take which examination belong to the specification you are working to, and this page holds none of them.
The duplicate check is the one piece of arithmetic that is not a tally. Each line that declares a first weld number claims the closed range from that number to that number plus its weld count minus one. The tool sweeps the ends of those ranges and reports how many individual weld numbers fall inside two or more of them, so a map with ten thousand welds costs the same to check as one with ten.
How to build a weld map and read its summary
One line per run of welds, then read the sheet back before you issue it.
- Split the assembly into runs. A run is a set of consecutive welds that share the same WPS, the same welder, the same NDT method and the same status. Where any one of those changes, start a new line — that split is itself the record.
- Number the welds. Type how many welds the line holds and the first weld number it claims. The line then owns that number and the ones after it, which is what lets the tool find two lines claiming the same weld.
- Fill the four columns that matter. Joint, WPS slot, welder slot and NDT method. Leaving a WPS or a welder unassigned is allowed, and the summary counts those welds separately so an unfinished column cannot pass unnoticed.
- Read the running summary. Welds per WPS, welds per welder, NDT coverage, welds still open, and any weld number claimed twice. Everything recomputes as you type, so the sheet is checked while it is being written rather than after it is issued.
- Set the extent your plan requires. Type the NDT coverage this map has to reach and the tool reports the margin in points, plus how many more welds would need a method to close a shortfall.
- Export and carry it forward. The CSV holds every field of the sheet, blank lines included, and the summary computed from it. Write your real WPS numbers and welder stamps against the slots, then import it into the system that holds your controlled records.
- WPS 1 to 6 and Welder A to F are slots, not references. The page cannot know your procedure numbers or your welder stamps, and inventing them would be worse than leaving them abstract. Write the real reference against each slot on the exported sheet; the counts follow the slots either way.
- Granularity decides whether the coverage figure is honest. A line is one NDT method for every weld it holds. If four welds out of twelve are radiographed, that is two lines, not one — and the discipline of splitting it is the same discipline the finished map needs.
- An unassigned column is counted, not ignored. Welds with no WPS and welds with no welder are reported separately, because a map whose columns are still empty is the state in which most sheets are abandoned, and the summary should say so out loud rather than quietly counting zero.
- A repair is a new entry, not an edited status. When a weld is cut out and rewelded, the original weld, its examination result and the repair each have a history worth keeping. Setting a line to rejected records the finding; add the repair as its own line rather than overwriting what happened.
- The map is a plan until something measures the weld. Which procedure a joint was welded to is an assertion; what the arc delivered on that joint is a measurement. See welding parameter monitoring for how current, voltage and wire feed speed get recorded per weld, and digital welding quality records for tying those records to the map line they belong to.
For the fields a weld map has to carry, the numbering systems in use and what an incomplete map costs at audit, read the weld map documentation guide.
Questions engineers ask about this calculation
How is NDT coverage worked out from a weld map?
On this page it is a count of welds: the welds whose line carries MT, PT, RT, UT or PAUT, divided by the welds in the map, expressed as a percentage. Visual inspection is treated as applying to every weld and is deliberately not counted, because counting it would put every map at 100 % and hide the figure anyone is actually asking about. The number is only as good as the granularity of the sheet — a line of twelve welds where only four are radiographed has to be split into two lines, or the sheet counts all twelve as examined.
Why does this builder ask for a weld number range instead of one row per weld?
Because a weld map is written in runs. A spool has eight butt welds on one procedure by one welder with one examination requirement, and typing that eight times is transcription work, not engineering. A line here declares the first weld number and how many welds follow it, which is the same information a marked-up isometric carries, and it keeps the arithmetic on ranges rather than on individual rows. Where a run genuinely breaks — a different welder halfway, one joint pulled for radiography — the run is split into two lines, and splitting it is exactly the act of recording that the welds are no longer the same.
What does it mean when two map lines claim the same weld number?
It means the sheet is wrong, and it is worth catching before the sheet is issued rather than during a review. A weld id addresses exactly one weld: it is the key that ties one joint to one procedure, one welder, one examination report and one result. When two lines overlap, at least one weld has two histories and neither can be shown to be the right one, which is the failure mode that turns a paperwork error into a re-inspection. The tool counts the overlapping numbers and says how many, so the ranges can be pulled apart on the spot.
Should NDT extent be counted by weld or by length of weld?
Both bases are in use and they are not interchangeable, which is why this page returns the count and the length side by side. A percentage of welds treats a 60 mm socket weld and a 900 mm circumferential butt as one unit each; a percentage of length weights them by how much metal there is to examine. Fabrications with a wide spread of joint sizes will read very differently on the two bases, and the same map can satisfy one and miss the other. Read the extent clause you are working to, decide which basis it is written in, and compare against that figure rather than against the more convenient one.
How many welds should one welder hold on a single weld map?
There is no general number, and any page that gives you one is inventing it. What the concentration figure is for is visibility: a single welder holding most of a map means a single qualification, a single continuity record and a single set of habits carries most of the risk on that assembly, and one lapsed certificate or one adverse test result puts the whole sheet in question. It also tells you where a re-inspection would land. Read the busiest-welder share as an exposure figure that informs how work is distributed, not as a limit anybody has set.
Does a weld map replace the WPS and the welder qualification records?
No. The map is the index, not the evidence. It records which procedure and which welder apply to each weld, and the procedure specification, the qualification record behind it, the welder certificate and the continuity log all remain separate documents that the map points at. The value of the map is precisely that it makes those pointers checkable one weld at a time — which is also why an empty WPS or welder column is worse than a missing document, because nothing tells you which document was supposed to be there.
Can the exported file be used as the controlled record?
Treat it as a working sheet. The CSV carries every field of every line as it was typed, blank lines included, plus the summary computed from it, and it is built in your browser rather than on a server. What it does not carry is the thing that makes a record controlled: an identity, a revision, a date of issue and a signature under a documented system. Import it into the system that holds those, or paste it into the map template your quality plan already names, and keep this page for the stage where the sheet is still being built and checked.
A weld map records what was intended. It cannot record what the arc did.
The map says weld 104 was laid to WPS 1 by welder A and passed radiography. WeldTrace records current, voltage and wire feed speed at 25 kHz on that weld, with shielding gas flow alongside, and HeatCore AI scores its thermal signature, so the line in the sheet is backed by a measurement from the seam instead of by a signature collected afterwards.
