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Today in the R. L. Deppmann Monday Morning Minutes we share the documents available after you have made your pump selection.
Let’s begin with a double suction tower water pump selection. The design capacity is 1200 GPM at 70 feet and the calculated suction pressure at design flow rate is only 1 PSIG.
In this example selection, we will also look at the NPSH or net positive suction head required by the pump. 1 PSIG is about 36 feet of absolute pressure available. We will default to a safety factor of 2.0 so we want a pump with 36/2 = 18 feet of NPSH required. We run ESP-Systemwize and look for a side suction pump since we have a low inlet pipe. We select a Bell & Gossett VSX-VSCS 5X6X10.5A with a 30 HP 1780 RPM motor. The NPSHr is only about 9 feet and the efficiency is the best of the selection.
Let’s gather information for our files. Let’s start by gathering documents. We have previously signed in and have a password, so what can we get when we click documents?
The submittal at the top of the list gives the curve and dimensions, but the summary has a great deal for you to schedule including efficiency, NPSH, and the weight. You may also download the Revit or CAD file.
The schedule portion is still work in progress, but most engineers have a schedule format they use anyway. Finally, if we scroll down, there is an IOM and a parts list that will be used later in the construction process.
Finally, we can select the triple duty valve for the discharge. We would not use a suction diffuser and instead look to detail the 5 pipe diameters coming directly into the pump with an eccentric reducer. The triple-duty valve and pressure drop is available with a click on the left-hand side navigation bar.
