The retired legacy_pressure_v1 contract is refused, even when its pressure is zero. A pressure-free document has no pressure contract. The former pressure treatment omitted Poisson contraction and longitudinal pressure stress. Its incorrect loads belong to historical results.

Models 0.3.0 and 0.4.0 accept exact_straight_pressure_v2 and its successor exact_pressure_v3, contract 3.0.0. The former is contract 2.0.0 and remains straight-only. New pressure authoring writes contract 3.0.0, including straight-only documents. The successor admits straight circular pipe and realized curved bends with linear restraints or springs. Both require explicit case pressure regions, terminal ownership, closure-transfer paths and E/ν, with derived G. Members use the homogeneous isotropic material basis. Each pressure region has equal bore.

The successor uses signed internal differential pressure with zero external pressure increment. A negative differential is admitted; external-pressure stability and collapse are not assessed. Pressure is uniform within each declared region. Mechanical, pressure-eigen and cap-transfer terms remain distinct.

Steady-flow momentum, transient pressure loads, Bourdon opening, pressure-dependent flexibility or stress intensification, ovalization and hydrostatic head are excluded. Pressurized joints, nonlinear or constant-effort supports, combinations and equivalent-static generators are refused on this route. Its name does not establish general exact pressure theory.

Successor pressure-1 results are readable on the desktop, but every desktop output surface refuses them with PRESSURE-1-OUTPUT-NOT-YET-AVAILABLE. A readable result does not establish export availability.

Meanwhile: use a supported, explicitly declared pressure model. Re-author refused legacy inputs; do not repair their results by adding a stress term.

A realized curved_bend_macro_element uses the entered radius, bend-plane reference and finite positive flexibility factor. The current element uses stable small-angle calculations and global-frame assembly. The mechanics_geometry_only mode still uses the chord.

The earlier review recorded anchor forces about 58 % high and elbow stress about 23 % low for that chord treatment in an L-bend. Those figures do not qualify the current curved mode.

The successor pressure route admits realized bends, with one user factor for both bending planes. It includes pressure free strain and member-owned end-cap terms. Wall axial force and effective force remain distinct. A region changes direction only at realized bends; mitres and straight-to-straight kinks are refused. Geometry-only bends cannot carry pressure on this route.

Arc end and station values do not establish a governing arc stress maximum. Arc hoop and radial pressure values are withheld, as is an incomplete stress headline. Meanwhile: establish the model mode before interpreting bend results. A displayed bend alone does not establish curved mechanics.

The earlier review found apparently solved mechanisms with rotations of 10⁹ radians or more. Current structural paths apply numerical integrity and formation gates. Successful factorization alone does not establish physical stability or accuracy of every recovered quantity.

Meanwhile: look at the largest displacement and rotation of every run before reading anything else. Read the result’s numerical admission and coverage limits.

The earlier check could report checks passed while errors in some recovered member rows exceeded its criterion. The merged repair reforms stiffness and loads from the represented inputs, applies displacement corrections and bounds error in the recovered member actions. The bound assumes the prepared matrix’s inverse norm is no more than 1024 times its Hager estimate. It also depends on the arc re-formation limits stated in the numerical design. The bound covers the intended system re-formed at 128-bit precision from the entered binary64 primitives. It does not bound physical modelling error.

Supported linear cases use checked member recoveries only when prior integrity checks passed and the member bound is available. Cases already demoted to Sensitive retain their earlier binary64 recovery rows. Checked forces, stresses and reactions can differ from a binary64 recalculation using the displayed displacements. A missing member bound cannot produce checks passed.

The nonlinear-support route has no member-relative formation check yet. It publishes Sensitive with a named explanation, even when the support iteration converges. The rows remain available for inspection; convergence is not their numerical eligibility. Some stress-free cases can also be Sensitive and carry STRESS_FREE_WITHIN_NUMERICAL_PRECISION.

Meanwhile: read the standing and recovery evidence for the actual case. A numerical bound is not a check of the entered physical model or code compliance.

Ordinary preview-physics-1 publishes six signed support components where actions can be attributed. Ambiguous coincident rigid actions are withheld. Forces and moments must be interpreted with the declared frame and sign convention.

Historic precision-1 results retain force norms without moments; constant-effort reactions read zero. They remain readable but are not current or eligible for rules, reports or export. Meanwhile: take unsupported support loads from the validating program.

The ordinary user-SIF measure is equal-factor intensified bending, i*hypot(My,Mz)/Z, with the member section modulus. It is not code stress and is never combined. A realized curved-bend component supplies no measure on its arc or straight neighbors.

The retired row multiplied summary stress by SIF and, by default, flexibility factor. The historical test gave 699 MPa where 47 MPa was expected. Meanwhile: do not use that retired SIF row. A user-entered SIF is not a standards-derived factor or code acceptance.

Ordinary preview-physics-1 uses supported straight circular normal-stress extrema, with torsion as a separate stress component. It withholds arc maxima and any stress headline with incomplete member/case coverage.

The retired summary added |σ_by| + |σ_bz|. Circular bending instead uses √(M_y² + M_z²)/Z. The old sum could be up to 41 % high, omitted torsion and reported a first-case headline. Historical readability does not make these quantities eligible. Meanwhile: work from supported signed moments and their stated coverage.

Legacy finite-span joint definitions are refused and require re-authoring. Their former four-rate element is removed. The historical pipe-plus-joint and lateral-equilibrium defects do not describe the supported replacement.

The explicit objective connector replaces one straight span. It uses an authored symmetric 6×6 work matrix, frame, offsets and installed reference. Its law is linear, with small displacement and rotation. Current scope is untied, unpressurized hardware on the successor contract. Every case must have an empty pressure_regions list, including zero-valued or remote regions. The replaced span supplies no member result, self-weight or inherited load.

Pressure thrust, ties, finite rotation, geometric stiffness, temperature-dependent laws and stops remain unsupported. An annotation-only joint is disclosed as pipe; it supplies no joint mechanics and is refused on the pressure route.

Meanwhile: use only the explicit connector’s supported law and load scope. A drawn joint does not establish its solver mode.

The entered constant force acts in every solved ordinary load case, including thermal-only cases. It supplies no stiffness or restraint row. The ordinary result identifies the applied force; a historical zero reaction does not mean no force was applied.

Combinations are withheld when their factors would fail to count that force once. Model 0.4.0 does not provide device preload/reference laws or general hanger state history. Meanwhile: apply the hanger load as a force in the weight case only when using the inherited manual workaround. Do not also retain an active constant-force device.

A rate alone does not supply the installed cold load or hanger design. Spring base motion and device preload/reference states are refused on model 0.4.0. Inactive or locked participation is also refused. A spring acts along its declared axis; an additional rigid guide needs a separate support.

Meanwhile: in the sustained case, model a designed spring as a constant force equal to its hot load when that approximation is independently justified. This approximation does not provide automatic hanger design or all load states.

Ordinary preview-physics-1 withholds combinations for nonlinear supports, constant-effort double counting and mixed modulus bases. These guards replace silent linear superposition of incompatible states.

Meanwhile: solve each combined nonlinear loading as its own load case (Part III D). Exact-pressure and model 0.4.0 load/reference-state combinations remain unsupported.

An entered absolute mill tolerance reduces the wall used to derive section properties, including stiffness and weight. This differs from a nominal-wall flexibility model with allowances applied only to stress.

Meanwhile: leave mill tolerance out and reduce the stress section by hand when following that nominal-wall method. Keep the resulting stress calculation distinct from the program’s current section basis.

The product active-set iteration stops after four passes. The earlier rack examples with a dozen or more rests, or five friction shoes, exceeded this limit. A higher-limit investigation converged those recorded models; it does not establish general convergence or change the product limit.

Meanwhile: keep nonlinear supports to the few that matter. Treat non-convergence as a failed solve, not an approximate solved state.

Model 0.4.0 supports explicit installation, material, thermal and fit reference states for independently solved straight circular members. Rigid support translations and rotations are absolute prescribed boundary values. Thermal and fit strain compose once as lambda_fit*lambda_thermal-1.

Spring base motions, device preload/reference laws, inactive or locked supports, per-case mass states and installation/contact history remain unsupported. A fit reference strain is not a general cut-and-close joint model. Meanwhile: apply unsupported movements in the validating program.

Rigid component geometry and weight records do not establish a rigid solver element or applied component weight. A general reducer element remains unavailable. Meanwhile: confirm that component weight is absent from declared load sources. Then add its point force at the center of gravity.

Restraints act along explicitly listed global axes. The type does not infer directions. Skewed or pipe-relative restraints, two-sided gaps and general links between two nodes remain outside this support model. The vertical support acts on global Z.

Only supported spring families consume finite stiffness. Unused stiffness blocks the solve. Meanwhile: do not represent guides or line stops on skewed runs as though they were pipe-relative restraints.

Ordinary friction is a separate support on one global axis. Its normal force is explicit or comes from a declared linear support reaction. This does not provide general friction on a lifting rest or a coupled Coulomb circle. Independent sliding axes can produce the earlier square-law behavior.

General nozzle flexibility and nozzle-axis reporting remain unavailable. A tee does not supply a general flexible branch element or an independently established branch section modulus. Declared component modifiers do not create a code-qualified fitting model.

Hydrotest pressure is refused by the mechanics solver. Hydrostatic head and a coupled contents pressure/weight state remain unsupported. Model 0.4.0 refuses locked hanger participation and per-case mass states. Meanwhile: check hydrotest in the validating program.

Entered quantities need explicit compatible units. Supported inputs include bar, kN, kN·m, GPa, N/mm and °F. Unit conversion does not supply a pressure reference: barg and bara are refused unit symbols.

The earlier interface started in SI with meters. A display-unit setting does not alter the physical meaning of stored quantities. Pressure-reference assumptions belong in the explicit pressure contract.

Ordinary desktop solves run in capped local worker processes. The default pool is 75% of physical memory. The default per-solve worker budget is the smaller of 12 GiB and that pool; lower budgets are allowed. Larger per-solve budgets are not yet qualified.

Admission and worker growth check the pool, current memory pressure and conservative free-memory headroom. A solve can be refused before it starts or stopped during growth. Cancellation ends the worker; reservations are released after it exits. A resource refusal does not silently change the solver mode or numerical route.

The memory panel shows the selected budget, pool, reservations, queued work and refusal reasons. A pool above the recommended fraction requires acknowledgement; acknowledgement cannot bypass a headroom or qualification refusal.

The pool belongs to one app process. Its custody accounting counts delivered bytes and does not measure the webview heap. Other model commands do not yet have the solve ingress bound. The packaged CLI self-test runs outside this pool. These controls are not a whole-app memory guarantee or activation of the retained desktop route. Meanwhile: use the reported refusal to reduce the workload or free memory; do not infer that physical capacity guarantees a solve.

Mechanical load categories and user-authored rules do not provide a code stress implementation. Displacement ranges, allowables and code acceptance require the declared engineering method. The program supplies bounded force, moment and stress components (Part II K).

Formula evaluation supports intervals and refuses nonfinite intermediate arithmetic. A passing formula gate is not standards approval. Make the code check in the program you validate in.

The ordinary route selects a material basis per case and withholds mixed-modulus combinations. Model 0.4.0 declares per-member actual, selected and installation temperatures, expansion definitions and selected E/ν, with derived G.

These states do not automatically create operating conditions T1, T2 …, code stress categories or a cold-modulus displacement range (Part II D).

The earlier desktop .mbf export wrote a skeleton: nodes, pipes, anchors and guides. Missing sizes, materials, fittings, temperatures and loads, altered support types, and US coordinates labeled as millimeters made that output unsuitable for direct design use.

The current CAEPIPE MBF package is an explicit smoke subset with source-unit records, stable-ID sidecars and loss reports. Package construction does not establish complete interchange or target-program acceptance. Desktop output also depends on its route policy.

Meanwhile: use an admitted file only as a start for a model in the receiving program (Part V). Reconcile its loss report, units, geometry, properties, supports and loads.

Library import validates declared provenance and bounded payloads. An imported or selected record does not establish solve readiness. Hanger libraries require explicit identities, quantity provenance and supported units; missing engineering values remain absent.

No bundled catalog, sizing, ranking, source scraping or vendor parser is supplied by that import boundary. Standards, material and fitting data need their own valid sources and selection evidence.

Ordinary equivalent-static generators retain bounded behavior. Wind acts on entered exposed spans along the declared global axis. Straight pipes permit disjoint fractional extents. Overlapping extents or mixed whole-span and fractional declarations on one pipe are refused. Realized curved-bend spans require whole-span loading; partial extents are refused. Wind supplies no height profile or automatic projection perpendicular to the pipe. Seismic load acts in one sense per case on the declared axes. A generator does not provide a complete wind or seismic analysis.

Exact-pressure equivalents and combinations remain unsupported. Model 0.4.0 does not provide per-case mass selection or a coupled hydrostatic contents state.

The straight and curved beam formulations exclude shear deformation. Short, heavy legs can therefore differ from a model that includes shear flexibility.

Arc results include signed tangent-frame station resultants and nominal stress components. End force rows use the chord frame. End and intermediate conventions must be read from their metadata, not assumed identical.

The five sampled points do not establish a governing arc maximum. Ordinary preview-physics-1 withholds arc maxima and any incomplete-coverage stress headline.