Additional Exercises

1:

Consider the control valve diagram presented in Figure M15-5 and Equations (M15.16)–(M15.18). Find the gain between the fraction of valve opening, x, and the output of the orifice plate, DP, as a function of flow rate for each of the valves shown in Figure M15-5. Assume that the sum of the pressure drop across the valve and the orifice plate is constant. Assume that the constant pressure drop is 30 psig, and that at maximum flow, three quarters of the pressure drop is across the valve and one quarter is across the orifice plate. The gain calculation is shown conceptually below.

2:

Instrumentation Search. Select one of the following measurement devices and use Internet resources to learn more about it. Determine what types of signals are input to or output from the device. For flow meters, what range of flow rates can be handled by a particular flowmeter model? Vortex-shedding flowmeters Orifice-plate flowmeters Mass flowmeters Thermocouple-based temperature measurements Differential pressure (delta P) measurements Control valves pH