7.3LP Head Loss across a Valve Objective: A valve in a pipeline like that shown

Question

7.3LP Head Loss across a Valve Objective: A valve in a pipeline like that shown in Fig. P7.84 acts like a variable resistor in an electrical circuit. The amount of resistance or head loss across a valve depends on the amount that the valve is open. The purpose of this experiment is to determine the head loss characteristics of a valve by measuring the pressure drop, across the valve as a function of flowrate, Q, and to learn how dimensional analysis can be of use in such situations. Equipment: Air supply with flowmeter; valve connected to a pipe; manometer connected to a static pressure tap upstream of the valve; barometer; thermometer. Experimental Procedure: Measure the pipe diameter, D. Record the barometer reading, in inches of mercury and the air temperature, T, so that the air density can be calculated by use of the perfect gas law. Completely close the valve and then open it N turns from its closed position. Adjust the air supply to provide the desired flowrate, Q, of air through the valve. Record the manometer reading, h, so that the pressure drop, across the valve can be determined. Repeat the measurements for various flowrates. Repeat the experiment for various valve settings, N, ranging from barely open to wide open. Calculations: For each data set calculate the average velocity in the pipe, where is the pipe area. Also calculate the pressure drop across the valve, where is the specific weight of the manometer fluid. For each data set also calculate the loss coefficient, where the head loss is given by and is the specific weight of the flowing air. Graph: On a single graph, plot the pressure drop, as ordinates and the flowrate, Q, as abscissas for each of the valve settings, N, tested. Results: On another graph, plot the loss coefficient, as a function of valve setting, N, for all of the data sets.

Explanation / Answer

Hi, there is no figure here. Request you to re-post the question with associated figure and rate this one. Thanks

Related Questions

Navigate

• Browse (All)
• Browse 7
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.