Water Horsepower = (Flow in GPM x Head in Feet) – 3960
In this formula, 3960 is a constant which converts the result of the multiplication of head and flow into water horsepower- but only if head and flow are expressed in feet and gallons-per-minute. The resulting value can be compared to the amount of input horsepower required to operate the pump, and the resulting ratio is the efficiency of the pump.
Centrifugal Pump Efficiency—What Is Efficiency?
In this multi-part series, we will investigate several aspects of centrifugal pump efficiency. First, I will define efficiency and give some examples. Next, I will examine some of the design criteria that ultimately dictate the efficiency exhibited by a particular pump.
Some Effects of Operating Pumps Away from Best Efficiency Point
Vibration can be caused by many factors and can create bending moments in the shaft, resulting in poor pump performance and risk of shaft failure. Excessive vibration can occur when pumps operate too far to the right of BEP, due in part to cavitation which causes hydraulic imbalances within the impeller as voids are formed by the vaporization of the liquid. Excessive vibration can also occur due to higher bearing loads associated with pump operation closer to run-out or shut-off conditions.
Pump Efficiency Explained
In this post, we’ll break down the meaning of pumping efficiency so we have a clear understanding of what’s being measured, what the numbers mean, and how it can affect your farming operations.In this post, we’ll break down the meaning of pumping efficiency so we have a clear understanding of what’s being measured, what the numbers mean, and how it can affect your farming operations.
Increasing concerns about CO2 emissions and energy costs has led to greater focus on energy use worldwide. Grundfos is uniquely positioned to ensure a correct understanding of efficiencies and how these combine with hydraulic free passage and constructional robustness in state-of-the-art wastewater pumps.
Head = 160 feet. We measured it at the discharge side of the pump and corrected it for the fact that the gage was two feet above the pump center line. Look at the following diagram where we have calculated the discharge head from the formula shown on the right hand side of the illustration. If there were any positive head on the suction side of the pump that head would have to be subtracted. A negative suction head would be added to the discharge head.
R. L. DEPPMANN NEWS AND INFORMATION
The DOE has established a way to calculate each unique PERSTD value for all of the different types of pumps covered in the standard. This is simply because pumps often vary in efficiency based on their type. For example, the DOE team determined that base-mounted end-suction flexibly coupled pumps are generally more efficient than vertical inline pumps and thus will have a lower PERSTD value.
Number of impellers
Regulation 547-2012 EC specifies the procedure to calculate the MEI for each type of pump and establishes a specific threshold value to be achieved: from 01-01-2015 the value MEI>0.4 has been imposed, representing the minimum value of the MEI for pumps. The value MEI=0.4 has a clear meaning in terms of product selection: by imposing this target MEI value, 40% of pumps present on the market before 2015 (the year of the market survey) can no longer be sold commercially. Most pump manufacturers were involved in a new design process of their products to provide them with an MEI>0.4.