# Standards Used

There are very few standards available for use when making fluid flow calculations. FluidFlow makes use of the latest standards and guides where possible. For calculating pressure losses across control valves for liquid and gas flow the software uses the following guide: ANSI/ISA-75,01.01-2007 - Flow Equations for Sizing Control Valves. For predicting all physical properties of water we use the IFC-97 formulations developed by the International Association for the Properties of Water and Steam. For calculation of liquid or gas flow pressure losses across orifice plates we use the publication from the International Organization for Standardization - ISO 5167-1:2003 Part 1. Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full. For calculation of liquid or gas pressure losses through nozzles we use ISO 5167-1:2003 Part 3. Relief Valves are calculated according to the ASME Code Section VIII & ISO 4126-1. Pump Viscosity HI Correction method calculated according to 2015 method. FluidFlow uses two calculation methods for predicting the pressure loss through relief valves, API RP 520 & ISO 4126. API RP 520 caters for Newtonian liquids, steam, gas/vapors and two-phase flow. ISO 4126 caters for liquid and gas flow only.