Pipe Flow (multi-phase) Calculator - API RP 14E v1

Subject

Whilst it is perfectly acceptable to define fluid flow in a pipe using classical theory, it remains a theoretical calculation and includes no margin for error and takes no account of unknown variables in practical applications such as bends & elbows.

The world’s most recognised authority on pipe and pipeline design and their specification is API and their related recommended practice is 14E
(RP 1111), which includes safety factors and limitations for their use in the oil and gas industry.

The principal limitation imposed in this recommended practice is fluid velocity, which is responsible for erosion of the pipe wall. As most industrial pipes and pipelines receive annual inspections, it is important that the expected erosion rate does not exceed acceptable levels between inspections. RP 14E also takes into consideration multi-phase fluid flow (gas and/or liquid), which is particularly damaging and unpredictable with regard to erosion.

APIpe is an alternative to CalQlata's Pipe Flow calculator incorporating the suggestions and recommendations proposed by the American Petroleum Institute for hydrocarbon transportation.

APIpe calculates the pressure drop, flow rate, velocity and velocity limitations of liquids, gases and 2-phase fluids according to RP 14E

Whilst APIpe only calculates average fluid velocities, it also sizes your pipe wall according to API with no need for further safety margins.

This pipe flow calculator works with specific ‘Imperial’ units, which best relate to RP 14E

Note: This calculator has not been officially endorsed by the API. It is CalQlata’s interpretation of the recommended practice

For help using this calculator see Technical Help

Pipe Flow Calculator for API Criteria - Options

Liquid

APIpe calculates the liquid flow in pipes along with expected pressure drop, average velocity of the liquid and its limitations for ‘flashing ahead’ (too fast) and solid deposition (too slow) and calculates the minimum recommended wall thickness for your pipe.

You enter:	and the pipe flow calculator for API criteria will provide:
Internal diameter Internal pressure Pipeline length Yield stress Surface roughness Corrosion allowance Flow rate	Average velocity Specific gravity Reynolds number Pressure drop Wall thickness Moody friction factor

Gas

APIpe calculates the gas flow in pipes along with expected pressure drop, average velocity of the gas and tells you if the expected pressure drop is excessive, which can negatively affect performance and system costs. This calculation option also calculates the minimum recommended wall thickness for your pipe.

You enter:	and the pipe flow calculator for API criteria will provide:
Internal diameter Internal pressure Pipeline length Yield stress Surface roughness Corrosion allowance Flow rate Temperature Compressibility factor	Average velocity Specific gravity Reynolds number Pressure drop Wall thickness Moody friction factor

2-Phase

APIpe calculates the two-phase fluid flow in pipes along with average velocity of the fluid, the expected pressure drop and also tells you if the flow rate is sufficiently low to avoid erosion and sufficiently high to avoid solid deposition. This calculation option also calculates the minimum recommended wall thickness for your pipe.

You enter:	and the pipe flow calculator for API criteria will provide:
Internal diameter Internal pressure Pipeline length Yield stress Surface roughness Corrosion allowance Liquid flow rate Temperature Compressibility factor Dynamic viscosity of oil Dynamic viscosity of gas Density of oil Density of gas Water cut Gas-Oil ratio	Composite density Maximum velocity Minimum area Minimum diameter Average velocity Liquid flow rate Pressure drop Wall thickness

Check minimum system requirements