Water carrying capacity of irrigation pipes

Hi everyone,

Selection of proper pipe size in micro irrigation system (MIS) is very important part.

Today i am going to share some details on water carrying capacity of irrigation pipes,

There are 2 main aspects which affects water carrying capacity of irrigation pipe viz,

• Pipe Size (i.e. Pipe ID, Pipe OD,Pipe weight,& SDR value of pipe)
• Velocity 

Lets discuss them in brief,

Pipe Size:
- Pipe size contains certain values like Pipe ID, Pipe Weight, Section Area of pipe etc.
Calculation of the above values can be done as under,


Pipe inside diameter (ID) :

Pipe weight (Wt):

Section Area:

Specific Dimension Ratio (SDR) of pipe:

It's method of rating a pipe's durability against pressure.

Please note that all the calculations are based on SDR 17 as irrigation pipes with this rating are used widely over here in India.

Fluid Flow Velocity in irrigation pipes:
-  The fluid velocity should not exceed to certain limits to avoid noise and damaging wear and tear of pipes & fittings.

Normally velocity in irrigation pipes should be between 1.0 to 2.0 m/sec.

Velocity can be calculated by,

Now with all the above equations you can calculate water carrying capacity of irrigation pipes by the formula below,

Well its a big hectic job to calculate all this....

So I've made an excel sheet for calculating the same in easy way.

 All Calculations are based on pipes with SDR 17.

You can download it from Here (Flow Calculator Download)

Just select pipe size from the drop down list shown as under,

And then enter velocity in the next cell,

So maximum discharge will be calculated in the cell. For better result and longer lasting age of your micro irrigation system, try to keep flow velocity under 1.5 meter per second.

You can also change the output unit from (m3/hr) to (LPS) by selecting drop down menu as under,

That's all for water carrying capacity of irrigation pipes.

You can get more information on other aspects of micro irrigation in the links below,

1. Basic aspects of Micro irrigation system design
2. Technical aspects of MIS design
3. Head loss & velocity in irrigation pipes
4. Video tutorials on Micro irrigation system design
5. Micro irrigation system components installation

Or Scan a QR code here,

I am a professional trainer for MIS system design, for cost & other information, please contact me on below mail address,

- Hardip Gajjar
  (hrdpgajjar@hotmail.com)