×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

FRICTION LOSS THRU .25" ID TUBING
3

FRICTION LOSS THRU .25" ID TUBING

FRICTION LOSS THRU .25" ID TUBING

(OP)
I AM LOOKING FOR FRICTION LOSS DATA ON .25" SS TUBING. THE VISCOSITY OF THE LIQUID IS 17,000 CPS, THE FLOW RATE IS 1 LB/MIN.  WE ARE TRYING TO PUMP THRU 4' OF .25" SS TUBING THEN THE CUSTOMER WANTS TO PUMP THRU A .080" ORIFACE. I CANNOT FIND FRICTION LOSS DATA FOR 1/4" TUBING TO VERIFY IF THIS IS EVEN POSSIBLE. CAN ANYONE HELP.

RE: FRICTION LOSS THRU .25" ID TUBING

3
You will need to calculate the pressure drop using a formula such as the Darcy-Weisbach equation.  The Cameron Hydraulic Data book published by Ingersoll-Rand has a detailed explanation of the calculations necessary.  Here is a short version that may be of some help:

Darcy-Weisbach equation                          ( LV)2
                                       friction loss= f ----------
                                                                D2g

where
           L = pipe length - ft
           D =average inside diameter of pipe - ft
           V =average pipe velocity in ft/sec
           g =gravitational constant (32.174 ft/sec squared)
           f =friction factor (dimensionless number that depends on the roughness of pipe
                                     ID and the Reynolds number)

With the viscosity you state, I believe you will have laminar flow (Reynold's number below 2000) so the roughness of the pipe ID has no effect and your friction factor would become:
                                      64
                             f = ----------
                                       R

 where
                                                  VD
           R = Reynold's number = -----------
                                                    v

where

           V and D as above
           v = Kinematic viscosity - ft squared/second

If your Reynold's number is below 2000, you have laminar flow.  If it is above 4000, the flow is turbulent and you will need to determine the friction factor.  That is more involved an requires yet another calculation using the Colebrook formula, unless you have access to further data about the 1/4 ID tubing.  For that, you might try the vendor of the tubing.

More information is also available from the Hydraulic Institute and their Pipe Friction Manual.  See their website at www.pumps.org.

Regards and good luck,  Jeff Helm

RE: FRICTION LOSS THRU .25" ID TUBING

The Darcy-Weisbach equation in the previous post for friction loss should not have the "L" term squared.

h = (f L/D) V2/(2g)

In the above form, a loss coefficient (for valves, fittings) can be substituted for (f L/D).

RE: FRICTION LOSS THRU .25" ID TUBING

Rick, thanks for your correction.  I did not notice the error in the formula when I posted it.  I was having trouble working out how to get the formulas to be clear.


Regards, Jeff

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close