Orifice Flow Meter API
Differential-pressure flow-meter maths (ISO 5167) as an API, computed locally and deterministically for orifice plates, venturi tubes and flow nozzles. The flow endpoint computes the mass and volumetric flow rate from the measured pressure drop across the meter, qm = Cd·ε·E·A·√(2·ρ·ΔP), where E = 1/√(1−β⁴) is the velocity-of-approach factor, β = d/D the diameter ratio and A the bore area — and it reports the throat velocity and the permanent (unrecovered) pressure loss. The pressure endpoint works the other way: from a known flow it returns the differential pressure the meter will develop, ΔP = (qm/(Cd·ε·E·A))²/(2ρ), and the permanent loss. The sizing endpoint solves the meter geometry: from a target flow and an allowable pressure drop it iterates the required bore diameter and diameter ratio, and flags whether β falls in the ISO-recommended 0.2–0.75 range. Each device type carries its standard discharge coefficient (orifice 0.61, venturi 0.984, nozzle 0.96) which you can override. Everything is computed locally and deterministically, so it is instant and private. Ideal for process, HVAC and instrumentation engineering tools, flow-meter selection and commissioning, and fluid-mechanics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is differential-pressure flow metering; for pipe continuity (Q=A·v) use a flow-rate API and for friction pressure drop use a Darcy-Weisbach API.
api.oanor.com/orifice-api
