ROSE-HULMAN Institute of Technology

Problem 1

The following data were gathered during pump testing for a certain pump.

• Required torque input = 35 ft-lbf
• Rotational speed = 3600 rpm
• Inlet pressure = 2.5 psia
• Outlet pressure = 30 psia
• Volumetric flowrate = 1000 gpm
• Height to inlet pressure gage = 2 ft
• Height to exit pressure gage = 5 ft
• Inlet flow line: 10 nominal schedule 40 pipe
• Outlet flow line: 8 nominal schedule 40 pipe
• Fluid: Octane (n-octane)

Find the power that reaches the fluid, the power input to the pump itself, and the pump efficiency.

Problem 2

Rather than use the pump tested in Problem 1, select a pump from Fig. 1 to use for the same flow conditions.

Figure 1: Composite rating charts for The Goulds 3196 family of pumps. (www.goulds.com)

Problem 3

A cooling loop for hydraulic fluid (MIL-M-5606) consists of:

• A heat exchanger whose curve of pressure drop versus flow rate is given in the Fig. 2.
• 150 ft of 3-in.schedule 80 pipe + 4 standard elbows ahead of the exchanger.
• 150 ft of 3-in. schedule 80 pipe + 4 standard elbows after the exchanger.
• 1 gate valve.

The fluid enters the exchanger at 200°F and leaves at 80°F. The loop leaves and enters the heat exchanger at the same level. The outlet reservoir has a sharp entrance, and an inlet reservoir is present. The system has a Goulds 1 ½ x 3-8 pump [characteristics given in Fig. 3] that runs at 1,750 rpm. The pump has an 7 ½-in. rotor. For this system

1. Plot the required head (in ft) versus volumetric flowrate (in gpm) for the loop with the gate valve fully open.
2. Find the operating point for part (a)

Figure 2: Heat exchanger pressure loss



Figure 3: Goulds pump characteristics (www.goulds.com)