Irricad

Hi!
When editing tapes for calculating load loss there is a factor (Kd) and in this case the value varies from 0 to 2, however some suppliers do not provide this value in the catalogs.
I would like to know if there is an impirical formula to estimate the barb factor (Kd) or when you don't know this value you could use the value 1 for example!
If using zero or 2, what would be the influence on the pressure calculation in the project?

Hi Marcio,

The emitter barb factor (Kd) is used to calculate the headloss past the emitter and uses the formula H = Kd V² / 2g.

The easiest way to determine the emitter barb factor is a manual iteration process:-
- draw out several tapes (e.g., 100m , 200m, 300m)
- connect them to a large pipe and control valve
- Analyze
- change the emitter barb factor in the database until the expected headloss is achieved.

The IRRICAD Team

OK!
I found a thesis here in Brazil where they arrived at an equation to estimate Kd.
I will exercise in the field and also do as you said.

https://www.scielo.br/scielo.php?script ... 9000100004

Gracias a todos por el aporte respecto a los valores de Kd.

Saludos.

Jabes Medeiros.