Choosing a pump can be confusing if you are unaware of the different pump specifications and categorizations, specifically when it comes to ratings for different voltages (also known as dual voltage pumps).
Posts about Education
Spacing saving vertical pump system design reduces footprint in university’s mechanical room.
A major North American university needed a new science building to address the space requirements based on evolving educational needs. The new laboratory building was constructed to LEED (Leadership in Energy and Environmental Design) standards. An advanced mechanical room was required to ensure the building would operate sustainably and efficiently. The engineering firm faced the challenge of designing a multi-million-dollar system that would adjust to new requirements in terms of flexibility, while maintaining a small footprint. The system, consisting of six layers of piping and 16 pumps, required a specific sequence of installation, and had to meet specific seismic mounting and vibration requirements.
Mission Communications hosts free, informational webinars every Wednesday. Everyone interested in learning more about the fully pre-packaged, cost-effective, turnkey SCADA is encouraged to join.
These interactive webinars are designed for users to ask live questions about any monitoring or Mission subject they would like addressed. The focus of the webinars will vary week-to-week, with the general subject matter repeating on a month-to-month basis. Customers are welcome to ask questions about monitoring and Mission-related topics even if they are not covered by the topic of the week. When signing up for the webinar, GotoMeeting software will be automatically loaded to the desktop, laptop, or mobile device. Users can use the microphone and speakers of their device to listen to the audio and ask questions or dial into the toll-free number that is provided at the start of the event.
Motor design is key to the performance and service life of a pump. But determining the size of the motor required to drive the pump is something people often struggle with. This is especially true of wastewater submersible pumps.
This article, written in July 2017 by Bo Gell, Americas product manager, wastewater, who has worked in Xylem’s Applied Water Systems business unit for six years. Gell has extensive experience in residential, commercial and marine pumps. Hayes Pump specializes in Goulds Water Technology products. Continue reading to continue learning from Bo.
It’s a common assumption that you can use motor nameplate information at face value. That applies to some, but not all nameplate data. A primary example is service factor (SF).
Generally, service factor is the measurement used to determine the peak performance at which a pump motor can operate. The National Electrical Manufacturers Association (NEMA) defines service factor simply as a multiplier that indicates the amount of additional load a motor can handle above its nameplate horsepower. The service factor industry standard for a totally enclosed motor is 1.0.
To determine the service factor horsepower of a motor, multiply the nameplate horsepower by the service factor. For example, if a 1 HP motor has a service factor of 1.5, the motor’s service factor maximum horsepower is:
(1 HP) x (1.5 SF) = 1.5 HP
However, when sizing submersible wastewater pump motors, horsepower service factor, which applies only to the motor, is not a primary consideration. While service factor can be used to handle intermittent or occasional overloads, designers cannot rely on the service factor capability to carry the load on a continuous basis. Doing so will likely result in reduced motor speed, and the reduced life and efficiency of the pump.
Designing Pump Systems for Continuous Duty
When sizing a submersible wastewater pump motor, it’s important to consider whether the pump will ever be required to operate at a flow rate higher than the design point. If, for example, the pump was allowed to operate at the end of the head capacity curve, the actual horsepower requirement may exceed the design point selected motor horsepower and overload the motor. For this reason, it is common practice to size the motor not for the design point, but for the end of the curve or maximum horsepower requirements.
In the example above, a 7.5 HP motor would adequately power the pump at a design point of 120 GPM at 150 feet; however, looking at the end of the curve, brake horsepower requirements call for a 10 HP motor.
It’s also important to note that submersible wastewater pumps follow Affinity Laws – the mathematic relationships that allow for the estimation of changes in pump performance as a result of a change in one of the basic pump parameters. If either the speed or impeller diameter of a pump changes, you can approximate the resulting performance change using the following:
Pursuing peak pump performance
Taking all of these factors into account, the NOL Horsepower (or non-overloading brake horsepower) is a more accurate criterion when it comes to sizing the motor for a submersible pump. The NOL Horsepower is the maximum power value calculated in order to handle the maximum power demanded by the pump at any point along the curve. NOL Horsepower represents the amount of real horsepower going to the pump, not just the horsepower used by the motor.
Although not typically listed as part of the operational information on the pump nameplate, NOL Horsepower is one of the key factors confirmed during pump performance testing. If motors overload at any point on the published curves during testing, listing agencies like UL and CSA will not award product certification to the motor vendor.
While the factors used to size a motor that will operate anywhere on the pump curve may not be those typically used as defined for standard NEMA motors, there are advantages. Selecting a pump/motor combination that will function under all possible operating conditions will result in higher efficiency, longer service life and uninterrupted performance — even in a continuous duty application.
Want to know how to improve your pump system performance? The U.S. Department of Energy’s Industrial Technologies Program (ITP) and the Hydraulic Institute (HI) have produced a guide called Improving Pumping System Performance: A Sourcebook for Industry. Their other guides include: compressed air systems, fan and blower systems, motors and drives, steam systems, and process heating systems.
There is almost no pumping process which does not use "dosing" in some way. Dosing technology is used for the production of chemicals and products as well as for their economical and ecologically beneficial application in manufacturing industries. A significant number of users of dosing technology are waterworks and sewage treatment plants as well as public swimming pools water conditioning. The spreading of dosing technology to increase the quality and economic efficiency of processes requires more information and training on “dosing technology“ so that optimum results can be achieved.
Lutz Jesco America has published an 80 page guide that provides detailed information on the dosing process, including drawings, tables, and detailed explanations - "A Brief Introduction to Dosing Technology". It explains the basic principles in a simple way with special attention given to installation of fittings/accessories that improve your end results.
Properties of media
- Solid, liquid and gaseous substances
- Solutions, suspensions, emulsions, colloids, coagulation, peptization
- Sedimentation, flotation, decantation
- Flow behaviour of bulk material
- Burning and explosion behaviour
A recent Pump audit conducted by Grundfos found multiple opportunties for savings - eliminating $4500 annual maintenance, 97% power consumption, as well as reducing the noise levels that were troubling residents. This case study provided by Grundfos covers the problem, the audit findings, and the solution that was implemented.
In chemical manufacturing facilities, there a wide range of pump types and pump applications.
John Crane recently helped Pumps & Systems editorial staff satisfy reader requests for articles on pump fundamentals. This article was written by John Morton, chairman of the European Sealing Association, and product marketing manager at John Crane. Since Power Generation has no tolerance for down time, your sealing choices can make a significant difference in keeping power reliable.
John states, "At the heart of any power station’s pre-boiler system is the boiler feed pump. Most of these pumps are between-bearings, multistage centrifugal designs with mechanical seals installed at each end of the pump." In this article, John covers:
- What is a boiler feedwater pump?
- Why are these pumps important?
- What sealing methods do plants typically use to keep boiler feedwater pumps running?
- What are the common issues with these methods?
- Are there other options?
What situations make the change to a newer sealing technology worth the cost?