M-1

A centrifugal pump delivers 300 gpm of water at 3,000 ft total dynamic head when operating at 3,500 rpm.

1. At what speed must a geometrically similar pump operate to deliver 200 gpm at the same total dynamic head?

2. What must be the diameter of the impeller of this new pump if the diameter of the 3,500-rpm pump is 6 in.?

M-2

A boiler-feed pump is driven by a variable-speed steam turbine. The characteristic curve of the pump at a speed of 6,000 rpm and the system-head curve of the boiler-feed-water system are shown in Fig. M-1. Determine the speed at which the pump should be operated to match a system requirement of 3,000 gpm.

Figure M-1

M-3

A model centrifugal pump with a 3-in. diameter impeller delivers 600 gpm of 60 F water at a total head of 350 ft when operating at 1,750 rpm. Find the diameter of a geometrically similar pump that will deliver 1,000 gpm when operating at 3,500 rpm. What will be the total head of the 3,500-rpm pump when it is delivering 1,000 gpm?

M-4

A centrifugal pump handles 1,500 gpm water at 150 F. Suction is from an open pit 5 ft below the pump center line and discharge is to an open tank 50 ft above the pump center line. Suction and discharge lines are 8 and 6 in. nominal size, respectively. Pipe is Schedule 40 (standard). The discharge piping system consists of 500 ft of pipe, 1 swing check valve,...