Use PIPE-FLO® software to determine the pressure drop across 50 ft of 4-in Schedule 40 steel pipe, carrying 77°F kerosene at a velocity of 6 ft/s if along the pipe there are also (4) standard 90° elbows, (1) knife gate valve, and (1) sharp-edged pipe entrance at the tank. The bends where the elbows

Question

Use PIPE-FLO® software to determine the pressure drop across 50 ft of 4-in Schedule 40 steel pipe, carrying 77°F kerosene at a velocity of 6 ft/s if along the pipe there are also (4) standard 90° elbows, (1) knife gate valve, and (1) sharp-edged pipe entrance at the tank. The bends where the elbows are installed are all in the same horizontal plane at the same elevation. Report all applicable values related to the solution such as Reynolds number and friction factor. Flow is caused by a pressurized tank with 50.0 psig above the kerosene and the depth of the tank is 7.0 ft.

Accepted Answer

Open a new project in PIPE-FLO® and select the “SYSTEM” menu on the toolbar to initialize all key data such as units, and pipe specifications the same way as the Example Problem in Chapter 8. For the “fluid zone” select “NEW” and follow the instructions to download the property data for kerosene and many other fluids from the ESI website. After downloading, initialize a fluid zone for kerosene at 77°F.
Place a closed pressurized tank on the FLO-Sheet® and draw in the pipe. Remember that we define the length of pipe in the property grid. The actual drawing of the pipe is not important, but the sketch below shows four turns to represent the elbows. Achieve this graphic by simply clicking the mouse in the desired corners and continuing with the pipe. The elevation of the pipe, since the entire problem is horizontal, is entered as 0 ft. Enter this value in the property grid after clicking on the pipe. Add a flow demand at the exit of the pipe to define velocity in the pipe. The flow rate, as calculated by using 6 ft/s velocity and [latex] 0.3355 ft^2 flow area, results in 238 gal/min. Use this value in the “Set Flow” category in the property grid for the flow demand.
With the basic system in place, it is time to add components that will be installed along the pipe. Components such as these are simply considered a part of the pipe in PIPE-FLO® so they are not drawn separately on the FLO-Sheet.® Instead, they are entered as values in the properties grid for the associated pipe. Start by clicking on the pipe. Under the “K (Valves & Fittings)” box in the property grid, click the “. . .” button and the table below appears on the screen.
To choose a particular fitting or valve, drop down the category that would contain the desired component and select it. Also, select the quantity of that component, and then select “ADD” to place it in the system. Multiple fittings and valves can be entered at the same time in the same way for convenience.
The 90° standard elbows are located under the “Fitting” heading. Select a quantity of (4) and then “Add”. Similarly, choose a knife gate valve and its quantity, then “Add” to place it in the system. If you aren’t sure whether the component is the one you need, verify that the “K” value specified in PIPE-FLO® matches the one you would use if you were doing manual calculations. The sharp-edged pipe entrance can be found under the “Fitting” heading; add it to the system the same way as the other components. When finished, the “Valves and Fittings” box should look like the box shown below.
After returning to the FLO-Sheet®, the symbols for the added components are visible. These symbols
are both moveable and changeable so they can be placed in their “proper” positions and modified to the users liking. The pipe entrance symbol isn’t shown, so be careful to make sure it is still included in the system. Also, only one symbol is shown for the elbows regardless of how many are placed in the system. In other words, the elbow icon indicates the presence of elbows, not the number of elbows. The final sketch of the system is shown below. Again, since the pipe can be drawn many ways, this is just one example of how it could be drawn. It is important to remember that calculations are done based on the data entered inside the worksheets, not the graphical image on the screen.
Since PIPE-FLO® treats the elbows, valves, and entrances as part of the pipe itself, results for individual components are not given, but rather the results for the pipe and all components taken together. To get results for an individual component, dedicate a single pipe to that component or do manual calculations. To find the total system pressure drop through the 50 ft of pipe, select “CALCULATE” as shown in the previous Example Problem in Chapter 8. The values given will reflect answers based on both minor losses and pipe friction losses. Remember that some values such as friction coefficient, Reynolds number, etc., aren’t shown immediately and must be added by turning them on in the “Device View Options” in the Property Grid. For this system then, the total head loss is 3.15 ft, while the pressure drop through the system is about 1.10 psi. Reynolds number and friction factor are 89 464 and 0.0204, respectively. Complete the problem by working it through hand calculations and compare your answers.

Question 10.14: Use PIPE-FLO® software to determine the pressure drop across...

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