5 replies to this topic

[Sprinkler]

In the fire sprinkler industry we use equivalent lengths for fittings and valves, which are expressed as a length. Such as 90 deg Elb 50mm = 1.50m. We also use the Hazen-Williams equation for pressure loss.

I would like to try to verify the equivalent length values to check their accuracy.

Can anyone suggest a method of doing this?

[kumaqal.engr]

For your refference please consult
Chemical Engineering Hand Book by R.Perry
A table is available here in this book against different fitting values & id's , in term of length, Beside this you can also find pressure drop per square feet from the graph given in this book.
with kind regards

[pleckner]

"Sprinkler"

Equivalent lengths are calculated numbers derived from the following equation:

K = fL/D

The equivalent length is the "L/D" part. "f" is the friction factor and "K" is the number of velocity heads. I invite you to read my ariticle on the subject, found on this site. On the main page, look at the menu choices on the left and choose free articles. Choose "Popular Articles" and you'll see it.

If you don't have a copy of CRANE Techical Paper 410, then you can use Perry's as suggested by "Kumaqal.eng" above for equivalent length values.

The published equivalent lenghts have been around since the dawn of time, OK, I exaggerate, but they have been used for many, many years. I personally don't like them and my article explains why. So I have to ask, exactly what you are trying to confirm?

[Art Montemayor]

Sprinkler:

I've done a lot of fluid flow and through the years I've accumulated a lot of information and data that I'm still compiling into a decent Excel Workbook. I haven't finished the workbook (I doubt I ever will), but if the attached is of some help, then be my guest.

The same goes for any enterprising and resourceful engineering student that is energetic and smart enough to join this Forum and look around for useful and profitable tools that will always come in handy. As you can imagine, compiling the data into useful tables and organizing all the loose information takes time and effort. I hope this work is useful to others. I still have twice the amount of information to add to the workbook - including my own spreadsheet on pipe sizing employing the Serghides equation for the friction factor.

Art Montemayor

P.S.: Read Phil Leckner's great article, included in the workbook.


 Art__s_Fluid_Flow.zip   329.87KB   231 downloads

[Zauberberg]

Great excel work, Mr Montemayor.
It looks like someone's whole life has been zipped into this file...

Best regards.

[jetul]

Well,
I really enjoyed by seeing the worksheet, and hope that u will surve this type of material for engineers........

It is a great work,

thanks
bye