Product updates
Changelog
New features, accuracy improvements, and fixes shipped to PV Cloud. Most recent first.
A better model for hillside and tilted nozzles
A nozzle offset from the shell centreline was previously modelled by adding a moment equal to the offset times the radial force, and that turned out to be wrong: on a check geometry it shifted the local stress by 78% where independent finite-element reference software showed a 1.5% change. Offsets are now treated the way ASME VIII-2 Part 4 treats a hillside opening — as an equivalent lean of the nozzle axis, with the applied forces and moments rotated into the shell's local axes. Rotating the loads is still an approximation of the real junction, but on the check geometry it tracks the reference's membrane-plus-bending change to within about half a percentage point, and 23 reference runs are now pinned as regression checks. The same round removed a spurious rotation about the nozzle axis that could put a purely longitudinal moment into the circumferential plane, and on heads, where the rotation does not apply, the tool now says so instead of silently guessing.
The headline now shows the governing load case
With more than one load case, the stresses at the top of the report were effectively a blend: forces were superposed across all cases while the pressure came from the first one, so the headline could contradict the per-load-case table and describe a condition that never physically occurs. Load cases are alternatives, not loads that act at once — each carries its own pressure, condition and temperature. The headline now reports the governing case, the one producing the most unfavourable effect, which is how ASME VIII-2 treats load-case combinations. Single-load-case designs are unaffected, and if a governing case cannot be resolved the report says so rather than falling back to a blend.
A reinforcing pad now has to be wide enough to count
WRC 297 Appendix A only lets a reinforcing pad be counted as added wall when its radial width reaches 1.65·√(R·T), measured out from the nozzle outside diameter — a narrower pad is too local to spread the load into the shell and earns nothing. The tool previously credited any pad that had a thickness, whatever its width. The width rule is now applied, so a narrow pad loses a credit it was not entitled to and the stresses it reports go up, which is the conservative direction; the report states the width and the criterion so the decision is visible. The rule covers circular nozzles on cylindrical shells, where pad credit is taken; on spherical and formed heads no credit was ever taken, so nothing changes there.
Incomplete results instead of invented ones
WRC 297 publishes its stress curves over a limited range and recommends against extrapolating past it. Previously, when a curve read fell outside that range the tool declined it internally but then used zero downstream, so a refusal could come out the far end as a confident 0.00 MPa pass. A refused read now stays unknown the whole way through: any check that depends on it is marked incomplete with the reason stated — which curve, which parameter, which limit — in both the app and the PDF, it is never shown as a pass, a fail, or a value, and checks the missing curve never touched still evaluate normally. In the same spirit, a design that cannot be assessed at all, most often because a material allowable is missing, now reads incomplete rather than failed, and where the tool interpolates between two published curves the valid range is now where both curves are plotted.
Correct AS 1210 acceptance limits
For AS 1210 projects, the acceptance limit the report printed and the limit it actually judged against could differ. Clause N3.5(c) sets three local membrane-plus-bending limits by location — 1.5·R_eT at a nozzle edge, 1.3·R_eT at a pad or solid-attachment edge close to the nozzle, and 1.5·f beyond that — but the tool was taking the lower of two of them regardless of geometry, so a hollow nozzle was judged against the pad-edge limit. The limit is now selected by geometry, the report prints the clause and symbol it applied, and the summary, acceptance section and conclusion all show the same value. For a hollow nozzle the judged limit rises from 1.3·R_eT to 1.5·R_eT, so a verdict can change even though no calculated stress moved; this round also adds an AS 1210 material selector that is aware of construction class, with expanded Table B1 data and validation in the picker.
Reports you can check by hand
A round of work on making the report re-checkable: every number printed on the page is the number that was actually used, so each equation can be reproduced from what is in front of you. The per-load-case inputs now travel to the report, so the design-loads table shows the real condition — operating or hydrotest — instead of a default that could contradict the allowable used elsewhere in the same report. The fill height and fluid density behind the hydrostatic head are printed so the head can be checked against the formula the report itself shows, imperial projects now convert every length and temperature correctly rather than most of them, and the WRC 297 curve read echoes its verdict and the coordinates it was read at. The 3D figure is also captured on a white background, and internal build numbering was removed from text users read.
Faster reports and lighter pages
A warm report render now takes single-digit seconds — roughly 4 to 8 seconds for a new design depending on the payload, and about 2 seconds when the same design is requested again and hits the cache. You can cancel a compile in progress, and an already-prepared report opens with no wait. On the public site, the authentication code no longer loads on pages that do not need it and report images are compressed and sized before they are served, so the landing and pricing pages are lighter.
A consistent touch experience on mobile
Every selector below the desktop breakpoint now uses a single bottom-sheet pattern with 44-pixel touch targets, replacing a mix of popovers, native selects and a centred modal. Load inputs are readable on a phone, the hydrostatic switch is tappable, the 3D viewer fills its sheet, and help tooltips open on tap instead of needing a hover. The step strip keeps the active step in view and shows that it scrolls, results rows no longer clip their name or verdict, forms autofill properly, and if a design is blocked from running you are taken straight to the field that blocks it. Dialogs, sign-in forms and inline text buttons all meet the same 44-pixel target, and the landing page's pinned report scroll became a before/after slider on mobile.
A redesigned workspace, top to bottom
The nozzle design tool has a cleaner, faster interface built around how the work actually flows: project, materials, geometry, loads, then results. Load cases now live in clear cards you can switch between, and each field highlights the matching arrow in the 3D model as you type. The landing and pricing pages were rebuilt to match, and the whole site now works properly on phones and tablets.
Links now preview properly
Sharing a PV Cloud link on LinkedIn, X, or in chat now shows a proper preview image and description instead of a bare URL. Nothing about the calculations changed.
Sharper 3D nozzle viewer
Section cuts and junction intersection curves are now computed from the exact shell geometry instead of approximations, and visual clutter around the model was removed so the shape reads clearly. Load arrows were corrected so longitudinal and circumferential forces and moments point the right way, and focusing a load field now highlights just that load in the view.
Independently verified calculations
We ran the nozzle engine side by side with independent finite-element reference software across more than 2,000 cases and reconciled every meaningful difference. Alongside that, a full unit-handling audit traced every value from input to report to confirm the units are correct end to end. Where we found discrepancies we corrected them, so results now line up more closely with the reference across the full range of geometries and load cases. Every equation is still shown in the report so you can check the work yourself.
PDF reports generate about 5x faster
Report generation was reworked so a standards-compliant PDF comes back in a fraction of the time it used to take. Figure rendering and caching were the biggest wins, along with tighter handling of large payloads. You get the same detailed report, just much sooner after hitting generate.
Reinforcing pads
Nozzles with a reinforcing pad can be analysed end to end. The junction type selector in the Geometry step offers five attachment types — set-on welded, set-through welded, set-on with a reinforcing pad, set-through with a reinforcing pad, and a pad with an internal segment — and choosing one of the three pad types opens fields for the pad outer diameter, thickness, radial width and the three weld legs. The pad is drawn on the shell in the 3D view and updates as you type. The pad's contribution is carried into the local stress at the junction, and the report adds a pad-edge check: the membrane hoop and longitudinal stresses at the weld toe, combined as a stress intensity and graded against the local allowable, with the junction type and every pad dimension echoed under a Reinforcement heading so the check can be reproduced by hand. Reinforcement credit applies to circular nozzles on cylindrical shells; on spherical and formed heads the pad geometry is echoed and the pad-edge stress is reported, but no credit is taken, and the pad is assumed to be the same material as the shell. This entry was added late — the feature shipped on this date but was never written up, which is why it was easy to miss in the tool.