A centrifugal pump supplies water at 170°F at a rate of 86 gal/min from a tank under a 20 in Hg vacuum to a tank vented to the atmosphere. The liquid level above the pump centerline is 16 ft. The pump suction line is a 12 ft length of 2 in schedule-40 steel pipe. The internal area of the pipe is 0.0233 ft². The suction line contains one long-radius elbow with a resistance coefficient of 0.4 and a valve with a resistance coefficient of 5.6. 170°F water has a vapor pressure of 6.0 lbf/in² and a density of 62.4 lbm/ft³. Under these conditions, the head loss due to friction in the suction line is 16.4 for each 100 ft of pipe. Assume the specific gravity of mercury is 13.61. Calculate the net positive suction head available.
Added by Lorenzo P.
Close
Step 1
Calculate the head loss due to friction in the suction line: 16.4 ft/100 ft of pipe = 16.4 psi Show more…
Show all steps
Your feedback will help us improve your experience
Madhur L and 74 other Chemistry 101 educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Adi S.
Madhur L.
The net positive suction head required $(N P S H R)$ by a pump may be expressed approximately as a parabolic function of volume flow rate. The $N P S H R$ for a particular pump operating at $1800 \mathrm{rpm}$ is given as $H_{r}=H_{0}=A Q^{2},$ where $H_{0}=10 \mathrm{ft}$ of water and $A=7.9 \mathrm{ft} / \mathrm{cfs}^{2} .$ Assume the pipe system supplying the pump suction consists of a reservoir, whose surface is $22 \mathrm{ft}$ above the pump centerline, a square entrance, $20 \mathrm{ft}$ of 6 -in. (nominal) cast-iron pipe, and a $90^{\circ}$elbow. Calculate the maximum volume flow rate at $70^{\circ} \mathrm{F}$ for which the suction head is sufficient to operate this pump without cavitation.
Recommended Textbooks
Chemistry: Structure and Properties
Chemistry The Central Science
Chemistry
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD