Contact US

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!

*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

Vane shape in a closed impeller

Vane shape in a closed impeller

Vane shape in a closed impeller

Hi everybody

I would be thankful if you let me know your viewpoint about the following

Today at a pump factory I saw a pump that had vanes with triangle cut. i.e., instead of having common straight/oblique cut it had a forward tringle shape. see the attached file where the red lines show the cut schematically.

do you know what is the reason for such a design? usually trimming is done such a way to increases the distance between the vane tip and the casing (the so-called gap B) via a backward triangle cut. However with such a cut, the distance between the center of the vane and the casing does not change.


RE: Vane shape in a closed impeller

Angling the tips of the vanes in a triangular pattern will tend to break up vane-pass frequency pressure pulsations. This is especially important if the "B" gap is close to the minimum recommended. I assume you are referring to an impeller with vanes tips like this:

Johnny Pellin

RE: Vane shape in a closed impeller

You can also cut the blade at 30 / 45 degree in lieu of the triangular, easier to calculate the RMS for the trim diameter.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. 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