Pressure drop calculator

incompressible flow, losses due to friction calculation

online since 2006

pipe flow calculator

Description

You can use pressure drop in pipe calculator for pressure drop and flow rate calculation for all Newtonian fluids (gases and liquids) with constant density (incompressible flow) in closed, round or rectangular duct.

If the system that you are analyzing has more than one pipe, you can use pipe network analysis calculator

Pressure drop calculator is suitable for laminar and turbulent flow regime. You can't use this calculator for compressible gas flow where the pressure of the gas is changing more than 5-10%. For that purpose, you can use one of available gas pressure drop calculators.

Registration and subscription

Select a subscription plan and enable the full service:

  • Switch between metric and imperial units in one click
  • Export calculation results in Word .docx or Excel .xlsx format
  • Preview results on one place and copy/paste it in your favorite text editor
  • Send results back to your email
  • Support the future of this project

And even more... Subscribed users have access to the full set of 19 calculators available as Java™ Web start application or download Windows™ 64bit application.

Subscribe

Full year service

Monthly cost
$250/month

Full year service $29.95/year

Action
Calculation setup
Pressures
Flow rates
Coefficients
Flow regime: Flow is turbulent
Pipe dimensions
Fluid properties

Exclusive calculator

On exclusive calculator page you can use the online calculator without interference from advertisements, additional text, links and other content that is not required for the calculations themselves. A pure experience of using a calculator as with a desktop application.

An exclusive version of the calculator is available to registered users. Choose the right subscription duration and start using the exclusive service.

Exclusive

Description

p1 - inlet pressure
Absolute pressure at the pipe start
p2 - outlet pressure
Absolute pressure at the pipe end
Δp - pressure drop
Pressure difference between pipe start and pipe end
q - volume flow rate
Fluid flow rate in terms of units of volume per unit of time
ṁ - mass flow rate
Fluid flow rate in terms of units of mass per unit of time
L - pipe length
Length of a pipe in which pressure drop is calculated
D - pipe diameter
Internal circular pipe diameter
H - channel height
The height of channel for rectangle shaped pipe
W - channel width
The width of channel for rectangle shape pipe
kr - pipe roughness
Pipe internal surface roughness
V - velocity
Flow velocity in terms of units of distance per unit of time
A - area
Internal pipe cross section area
f - friction coefficient
Coefficient of friction for pressure drop due to friction calculation
Re - Reynolds number
Dimensionless number representing viscous versus inertial forces ratio
δ - boundary layer
Thickness of laminar layer formed in turbulent flow connected to pipe wall surface
ρ - fluid density
Mass per unit of volume
ν - kinematic viscosity
Result of fluid particles colliding to each other and moving at different velocities in terms of area per square unit of time
μ - dynamic viscosity
Result of fluid particles colliding to each other and moving at different velocities in terms of mass per square unit of distance and time
K - resistance
Coefficient used for calculation of minor losses due to local resistances in pipe line like bends, tees, reducers, valves, etc.

Calculation setup

Select value to calculate. You should enter not selected one.
Δp
pressure drop
q / ṁ
volume/mass flow rate
D
internal pipe diameter
Select value to input. You should enter selected one. The other one will be calculated
p1
pressure on the pipe start
p2
pressure on the pipe end
Select value to input. You should enter selected one. The other one will be calculated
q
volumetric flow rate
mass flow rate
Select value to input. You should enter selected one. The other one will be calculated
ν
kinematic viscosity
μ
dynamic viscosity
Select pipe shape
round pipe
full cross section fluid flow
rectangular duct
for rectangle channels and full cross section flow

When Should You Use This Pressure Drop Calculator?

The pressure drop calculator is a powerful tool for calculating pressure loss in pipelines, tubing, and duct systems. It is ideal for engineers, designers, and professionals working with Newtonian fluids (liquids and gases) in closed, round, or rectangular ducts.

This pipe pressure drop calculator applies to incompressible flow, where the fluid density remains constant. It accurately determines pressure loss due to friction, pipe diameter, pipe length, and velocity changes.

If the fluid is a gas, ensure that pressure changes remain within 5-10% of the initial pressure. If the pressure drop exceeds this limit, use a compressible gas pressure drop calculator for more accurate results.

For gas calculations, the ideal gas law is applied, assuming perfect gas properties to compute unknown values such as pressure, temperature, and density.

This pressure drop in pipe calculator works for both laminar and turbulent flow regimes, making it applicable for various industries, including oil and gas, HVAC, and water distribution systems.

When Is This Pressure Loss Calculator Not Applicable?

  • Compressible Gas Flow: If gas pressure changes exceed 10%, use a compressible gas pressure drop calculator.
  • Non-Newtonian Fluids: The pressure loss in pipe calculator does not support fluids with viscosity changes due to shear rate variations.
  • Multiphase Flow: This pipeline pressure loss calculator is unsuitable for fluids containing solid particles, gas-liquid mixtures, or slurries.
  • Non-Ideal Gases: The piping pressure drop calculator assumes an ideal gas law, making it inaccurate for gases with varying thermodynamic properties.
  • Temperature-Dependent Viscosity: If viscosity changes significantly due to temperature fluctuations, this pressure drop through pipe calculator may not provide precise results.

Key Features of the Pressure Drop Calculator

This pressure drop calculation tool is built to handle a wide range of applications. Key features include:

  • Calculation of pressure drop and flow rate in pipelines, tubing, and ductwork.
  • Supports both laminar and turbulent flows, ensuring accuracy across different flow regimes.
  • Applies to water, air, oil, and gas systems, making it a versatile tool for engineers.
  • Accounts for pipe diameter, pipe length, viscosity, and velocity changes.
  • Works for closed-loop and open-loop systems, ensuring precise results for different designs.

Why Use a Pipe Pressure Drop Calculator?

Accurate pressure drop calculation is essential for designing efficient piping systems. Whether you are working on an HVAC system, an industrial pipeline, or a water supply network, minimizing pressure loss ensures optimal performance and energy efficiency.

Using this pressure loss calculator water can help optimize pump selection, reduce energy consumption, and prevent unnecessary maintenance costs due to high pressure losses.

How to Calculate Pressure Drop in Pipe?

To determine pressure loss in tubing or pipelines, input the following parameters into the pressure drop in pipe calculator:

  1. Fluid Type: Select water, gas, oil, or other Newtonian fluid.
  2. Pipe Diameter and Length: Enter inner diameter and total pipe length.
  3. Flow Rate and Velocity: Specify the flow rate or velocity of the fluid.
  4. Fluid Viscosity and Density: Input viscosity and density based on the operating temperature.

With these inputs, the pressure loss pipe calculator computes pressure drop per unit length and total pressure loss across the pipeline.

For water applications, the water pressure drop calculator or water pressure loss calculator provides highly accurate calculations. If working with narrow tubing, the pressure loss in tubing tool is recommended.

By using the right pressure drop calc, you ensure accurate, efficient, and optimized pipeline performance.

Professional-grade
pipe flow calculations
made simple

As low as $29.95 /year

Buy now!

Available in download version

save/open multiple results
export to Word and Excel
print results
create list of custom fluid properties
resistance factor K for flow in valves and fittings
pipe surface roughness selection
pipe material selection
select between gauge and absolute pressure
compressible isothermal flow
dry air isothermal flow
gas offtake flow
natural gas flow
ADMINISTRATOR ROLE NOT NEEDED

Preview Download

Calculator start selection

Read all about available deployments. In any way of utilizing calculator, Internet connection is not required, but nice to have for authentication at least.

Need a helping hand?

Powered by artificial intelligence - AI

chat_gpt_logo

Ask specific question related to pipe flow calculations and get answer from AI

Powered by natural intelligence - NI

calculation_guru

If you need a quick calculation, but you are not still familiar how to use the calculator, you can order calculation service from the calculator developer.

Order calculation service

pipe network analysis

Issues and answers

Having problems with calculators usage? Read more about known issues and problems and way to solve it.

Issues and answers

Watch how calculator can help you resolve task in less than a minute

PreDropWaterQ, D, L, kr, Δp

Example #10

Task: Calculate pressure drop in round pipe with flow of 5 m3/h, pipe length 100 m, internal pipe diameter of 25 mm and pipe roughness of 0.1 mm. Flowing fluid is water with density of 1000 kg/m3. Local resistance can be negligible K = 0.

Solution: Pressure drop is: 4.78 bar

PreDropWaterΔp, D, L, krQ

Example #11

Task: Calculate flow rate of water through closed round pipe with internal diameter of 25 mm, pipe length of 100 m. Pipe line connecting reservoir on the elevation of 20 m above the pipe exit with water flowing to open atmosphere. Reservoir is under atmospheric pressure. Pipe roughness is 0.1 mm.

Solution: Flow rate is: 3.16 m3/h

PreDropAirQ, H, W, L, krΔp

Example #12

Task: Calculate pressure drop of 2000 m3/h of air flowing through closed rectangle channel to open atmosphere. Chanel width is 400 mm and height is 250 mm. Chanel is with surface roughness of 0.01 mm. Local resistance coefficient is line is 3.5. Chanel length is 85 m.

Solution: Pressure drop is: 298.96 Pa

Related calculators available for download