Fluid & Pressure

Linear transmitter current to process value. Engineering fields are pressure; use generic linear scaling for other quantities.

Q = v A for a grille, opening, or duct. Enter area, or width × height, or diameter — not both area and geometry.

Darcy friction factor: 64/Re when laminar, Haaland when Re ≥ 2300.

Straight-pipe friction pressure drop from a known Darcy friction factor.

Required inside diameter for a target mean velocity. Does not pick a commercial size.

Normalized square-root flow: Q = Qmax √(ΔP / ΔPmax). Not an orifice sizing tool (see FLUID-23).

Airflow from measured velocity and rectangular or round duct size. Circular pipe continuity is also FLUID-01.

Expected transmitter current for a known process pressure.

Convert a fitting K into equivalent straight-pipe length.

Estimate flow from ΔP across an orifice, a known K, or a valve Cv. Pick the model explicitly.

Volumetric flow from mean velocity in a full circular pipe.

Q = ṁ cp (T_out − T_in) for a single fluid stream (water, glycol, air, process).

Gauge pressure from a liquid column. Height may be signed.

Linear 4–20 mA level. Optional tank height gives fill fraction and remaining headroom. Not a tank-volume geometry tool.

Fitting, entrance, exit, or valve loss from a lumped K.

NPSH available at the pump suction from absolute pressure, vapor pressure, and optional velocity head.

Incompressible flow through an orifice from differential pressure. Not a metering-standard calculation.

Velocity, Reynolds number, Haaland friction factor, and Darcy–Weisbach loss from pipe and fluid properties.

Annular metal cross-sectional area from outside and inside diameters.

External cylindrical surface area of a pipe (no end caps).

Compare observed pipeline ΔP to friction and elevation contributions.

Convert a pressure difference to fluid head, or head to pressure.

Hydrostatic pressure change between two elevations. Signed Δz is allowed.

Friction pressure gradient for screening a measured pipe gradient.

Pump differential head from suction and discharge pressure, with optional elevation and velocity terms.

Fluid power delivered by a pump from flow and head.

Shaft power from hydraulic power and pump efficiency.

Dimensionless Reynolds number from velocity, diameter, and dynamic or kinematic viscosity.

Convert specific gravity to density using a stated water reference, default 1000 kg/m³.

Normal stress from force and cross-sectional area.

Compare measured ΔP to calculated straight-pipe plus known K losses.

Full volume of a cylindrical, rectangular, or spherical tank.

Pressure transmitter span, midpoint, and engineering units per milliamp of a 16 mA live span.

Incompressible valve ΔP from US Cv: Q_gpm = Cv √(ΔP_psi / SG).

Mean velocity from volumetric flow in a full circular pipe.

Joukowsky surge estimate ΔP = ρ a ΔV. Not a transient simulation.