| ProjectSample Project — Demonstration Only | Job No.SAMPLE-001 | Client— |
| CalculationSnow and Ice Load on Piping Calculator (ASCE 7 Inputs) | Calc byPiping Toolset (calc-core) | Checked byUNCHECKED — sample |
| Date2026-07-31 | Rev0 | BasisASCE 7 Ch. 10 atmospheric ice / Ch. 7 snow, applied as a radial ice annulus and a projected-width snow line load (density and pf user-supplied) |
An NPS 12 bare line (12.75 in OD, no insulation) on an outdoor rack in a cold climate. ASCE 7 gives a design radial ice thickness of 0.5 in at a design ice density of 56 lb/ft³ for the site, with a design snow pressure of 20 psf. The pipe weight is left at zero so the card reports only the atmospheric load being added to the existing weight case.
| Outside diameter Do | 12.75 | in |
| Radial ice thickness | 0.5 | in |
| Ice density | 56 | lb/ft³ |
| Design snow pressure pf | 20 | psf |
| Pipe weight | 0 (added load only) | lb/ft |
Two line loads from the same geometry, reported separately and summed.
Ice, as a uniform radial annulus of thickness tice around the pipe. The annulus cross-sectional area is π·tice·(Do + tice) in square inches; dividing by 144 converts to square feet, and multiplying by the ice density gives weight per foot of run:
wice = ρice · π · tice · ( Do + tice ) / 144
Snow, as a design pressure acting on the projected width of the iced pipe. The projection is the outside diameter plus ice on both sides; dividing by 12 converts inches to feet, so the pressure in psf becomes a line load in lb/ft:
wsnow = pf · ( Do + 2 · tice ) / 12
wadded = wice + wsnow
wtotal = pipe weight + wadded
where Do is the outside diameter including insulation and jacketing — ice forms on whatever is actually exposed to the weather, and an insulated line collects a larger annulus on a larger circumference than the bare pipe would. The pipe weight input is the bare pipe plus contents plus insulation in lb/ft; entering 0 reports the added atmospheric load alone, which is what you want when you are handing an incremental load case to a stress model that already carries the pipe weight.
Both material values are yours from ASCE 7. The ice density is the design value that standard specifies for atmospheric icing — it is meaningfully less than solid ice, because accreted glaze is not solid, and using a textbook density for pure ice overstates the load. The design snow pressure pf comes from the ground snow load for the site with the standard's exposure, thermal and importance factors applied. Neither is embedded here.
The engine validates that the diameter is positive and that thickness, snow pressure and pipe weight are non-negative, and that the ice density is positive whenever an ice thickness is entered. Setting tice = 0 suppresses the ice term and pf = 0 suppresses the snow term, so a single card covers the ice-only case, the snow-only case and the combined case. Status is always COMPUTED — this is a load generator, and there is no pass or fail until the load reaches a span, a support or a stress check.
| wIce — ice line load | 8.094 | lb/ft |
| wSnow — snow line load | 22.917 | lb/ft |
| wAdded — ice + snow | 31.011 | lb/ft |
| wTotal — total line load | 31.011 | lb/ft |
The result values above are locked as fixture snow-ice-load.json, case
“NPS 12 bare, 0.5 in ice (56 pcf) + 20 psf snow”, tolerance 0.01, in the calc-core continuous
verification gate (see https://pipingtoolset.com/trust/validation.html). Allowable-stress and factor data are
user-supplied inputs; citations: ASCE/SEI 7, Minimum Design Loads and Associated Criteria for Buildings and Other Structures — Chapter 10, atmospheric ice loads: design ice thickness, ice density, and the concurrent wind speed to be paired with the ice case. Values are user-supplied from the governing edition. · ASCE/SEI 7 — Chapter 7, snow loads: ground snow load and the exposure, thermal and importance factors that produce the design snow pressure entered here. · ASME B31.3, Process Piping — ¶301.3 and ¶302.3.6, where snow and ice enter as dead weight in the sustained case and as an occasional load in combination with wind or earthquake, depending on the project's load definitions. · The geometric constants are unit conversions only — 144 in²/ft² for the ice annulus area and 12 in/ft for the snow projected width. No code table values are embedded.