PD ISO/TR 15377:2018 Measurement of fluid flow by means of pressure-differential devices. Guidelines for the specification of orifice plates, nozzles and Venturi tubes beyond the scope of ISO 5167

Venturi tubes
Diameter
Flow rates
Instructions for use
Geometry
Dimensions
Enclosed
Differential-pressure flowmeters
Flow measurement
Fluid inlets
Flowmeters
Flow nozzles
Mathematical calculations
Conical shape
Square shape
Orifice flowmeters
Holes
Channel flow
Fluid outlets
Pipes

Link: PD ISO/TR 15377:2018 Measurement of fluid flow by means of pressure-differential devices. Guidelines for the specification of orifice plates, nozzles and Venturi tubes beyond the scope of ISO 5167
Source: BSI Standards