1 · Design inputs

Bare NPS 8 (8.625 in OD) line on an outdoor rack. Basic wind speed 115 mph, Kz = 0.85 at the rack elevation, no topographic speed-up (Kzt = 1.0), Kd = 0.95, Ke = 1.0, gust factor G = 0.85, force coefficient Cf = 0.7 for the round section.

2 · Method

ASCE 7 §26.10.2 velocity pressure at height z, US-customary form (Eq. 26.10-1):

q_z = 0.00256 · K_z · K_zt · K_d · K_e · V²

The design wind force on an "other structure" is F = q_z·G·C_f·A_f (§29.4.1, Eq. 29.4-1). For a horizontal pipe run the projected area per foot of length is D_proj/12 ft²/ft, so the force collapses to a uniformly distributed load:

q_design = q_z · G · C_f

w = q_design · ( D_proj / 12 )

where V is the basic wind speed in mph for the risk category and return period of the governing edition, K_z the velocity pressure exposure coefficient at the pipe centreline elevation, K_zt the topographic (speed-up) factor, K_d the wind directionality factor, K_e the ground elevation factor, G the gust-effect factor, C_f the force coefficient for the round section, and D_proj the projected width in inches — the outside diameter plus insulation and jacketing, not the bare pipe OD. The 0.00256 coefficient is the standard air-density constant of Eq. (26.10-1); it is an equation constant, not a tabulated value.

3 · Calculation

1. Collect the coefficient product: K_z·K_zt·K_d·K_e = 0.85·1.0·0.95·1.0 = 0.8075.
2. Square the wind speed: V² = 115² = 13,225 mph².
3. Velocity pressure: q_z = 0.00256·0.8075·13,225 = 0.0020672·13,225 = 27.3387 psf.
4. Design pressure on the projected area: q_z·G·C_f = 27.3387·0.85·0.7 = 27.3387·0.595 = 16.26654 psf.
5. Projected area per foot of pipe: D_proj/12 = 8.625/12 = 0.71875 ft²/ft.
6. Distributed load: w = 16.26654·0.71875 = 11.6916 lb/ft acting horizontally on the run.

4 · Results COMPUTED

5 · Verification statement

The result values above are locked as fixture wind-asce.json, case “V=115 mph, Kz=0.85, Kd=0.95, G=0.85, Cf=0.7, NPS 8 bare”, tolerance 0.001, 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 7, Minimum Design Loads and Associated Criteria for Buildings and Other Structures — §26.10.2, Eq. (26.10-1), velocity pressure qz. · ASCE 7 — §29.4.1, Eq. (29.4-1), design wind force F = qz·G·Cf·Af on other structures; Fig. 29.4-1 force coefficients for round sections (values user-supplied, not embedded). · ASCE 7 — §26.5 basic wind speed, §26.6 directionality Kd, §26.8 topographic factor Kzt, §26.9 ground elevation factor Ke, §26.10 exposure coefficient Kz, §26.11 gust-effect factor G — all user-supplied from the governing edition. · ASCE 7 — Chapter 10, atmospheric ice loads (not evaluated here). · ASME B31.3, Process Piping — ¶302.3.6, allowances for variations from normal operation (occasional loads such as wind and earthquake).