Skip to main content

The Not-So-Silent Risk of Improper Controls - Water Hammer

The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

or click here to sign up for a free trial


Whether large or small pumps, there comes a debate when multiple drive motors are used to cover a broad range of output flow requirements: use one Variable Frequency Drive (VFD) plus a number of softstarts, some small and some large pumps with or without VFD's, one or more VFD's on a group of pumps, and all combinations in between. Equipment rotation and maintenance, starts per hour, starts per day, minimum flows, maximum demands, etc., all are considerations and decisions to be made. Many of these combinations invoke unintended hydraulic consequences. The focus of this paper is the benefits of synchronous, closed transition hand-off between VFD's and utility powered devices in multi-motor applications. Using off-the shelf, standard, available equipment that can synchronize drive output with across-the-line loads, the best of numerous options can be had while reducing power costs, protecting personnel and equipment, and achieving process control.

Keywords: Control; VFD; Variable Frequency Drive; Water hammer; check valve; closed transition; equipment protection; safety; synchronization

Document Type: Research Article


Publication date: January 1, 2010

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more