Natural gas ( = 0.0044 slugs/ft3 and = 5.2 105 ft2/s)is pumped through a horizontal

Assume a cars exhaust system can be approximated as 14 ft of 0.125-ft-diameter cast-iron pipe with the equivalent of six 90 flanged elbows and a muffler. (See Video V8.14.) The muffler acts as a resistor with a loss coefficient of KL = 8.5. Determine the pressure at the beginning of the exhaust system if the flowrate is 0.10 cfs, the temperature is 250 F, and the exhaust has the same properties as air.

The pressure at section (2) shown in Fig. P8.66 is not to fall below 60 psi when the flowrate from the tank varies from 0 to 1.0 cfs and the branch line is shut off. Determine the minimum height, h, of the water tank under the assumption that (a) minor losses are negligible, (b) minor losses are not negligible.

Repeat Problem 8.66 with the assumption that the branch line is open so that half of the flow from the tank goes into the branch, and half continues in the main line.

The 1 2-in.-diameter hose shown in Fig. P8.68 can withstand a maximum pressure of 200 psi without rupturing. Determine the maximum length, , allowed if the friction factor is 0.022 and the flowrate is 0.010 cfs. Neglect minor losses.

The hose shown in Fig. P8.69 will collapse if the pressure within it is lower than 10 psi below atmospheric pressure. Determine the maximum length, , allowed if the friction factor is 0.015 and the flowrate is 0.010 cfs. Neglect minor losses.

According to fire regulations in a town, the pressure drop in a commercial steel horizontal pipe must not exceed 1.0 psi per 150 ft of pipe for flowrates up to 500 gal/min. If the water temperature is above 50 F, can a 6-in.-diameter pipe be used?

As shown in Video V8.15 and Fig. P8.71, water bubbles up 3 in. above the exit of the vertical pipe attached to three horizontal pipe segments. The total length of the 0.75-in.- diameter galvanized iron pipe between point (1) and the exit is 21 in. Determine the pressure needed at point (1) to produce this flow.

Water at 10 C is pumped from a lake as shown in Fig. P8.72. If the flowrate is 0.011 m3 /s, what is the maximum length inlet pipe, , that can be used without cavitation occurring?

At a ski resort, water at 40 F is pumped through a 3-in.- diameter, 2000-ft-long steel pipe from a pond at an elevation of 4286 ft to a snow-making machine at an elevation of 4623 ft at a rate of 0.26 ft3 /s. If it is necessary to maintain a pressure of 180 psi at the snow-making machine, determine the horsepower added to the water by the pump. Neglect minor losses.

Crude oil having a specific gravity of 0.80 and a viscosity of 6.0 105 ft2 /sec flows through a pumping station at a rate of 10,000 barrels/hr. The oil then flows through 120,000 ft of 24-in. ID, horizontal, commercial steel pipe, enters another pumping station at 20 psig, and leaves at a discharge pressure equal to the discharge pressure of the previous pumping station. Calculate the discharge pressures and the power supplied to the crude oil at the second pumping station. See Fig. P8.74.

A motor-driven centrifugal pump delivers 15 C water at the rate of 10 m3 /min from a reservoir, through a 2500-m-long, 30-cm I.D. plastic pipe, to a second reservoir. The water level in the second reservoir is 40 m above the water level in the first reservoir. The pump efficiency is 75%. Find the motor output power. The pipe entrance is square edged.

An emergency flooding system for a nuclear reactor core is shown in Fig. P8.76. Find the power input required to flood the core at the rate of 5000 gal/min. Assume a square-edged entrance, 60 F water, and threaded connections.

A hydraulic turbine takes water from a lake with the piping system shown in Figure P8.77. Find the head ht available to the turbine for flow rates of 0, 5000, 10,000, 15,000, and 20,000 ft3 /min

Water flows through a 2-in.-diameter pipe with a velocity of 15 ft/s as shown in Fig. P8.78. The relative roughness of the pipe is 0.004, and the loss coefficient for the exit is 1.0. Determine the height, h, to which the water rises in the piezometer tube.

Figure P7.79 shows the 60 F water flow rates from the branches of a main supply line. Find the total pressure drop (pA pE) for soldered copper pipe. Assume that the loss coefficient for each tee is based on the threaded type.

Water is pumped through a 60-m-long, 0.3-m-diameter pipe from a lower reservoir to a higher reservoir whose surface is 10 m above the lower one. The sum of the minor loss coefficient for the system is KL = 14.5. When the pump adds 40 kW to the water the flowrate is 0.20 m3 /s. Determine the pipe roughness.

Natural gas ( = 0.0044 slugs/ft3 and = 5.2 105 ft2 /s) is pumped through a horizontal 6-in.-diameter cast-iron pipe at a rate of 800 lb/hr. If the pressure at section (1) is 50 psi (abs), determine the pressure at section (2) 8 mi downstream if the flow is assumed incompressible. Is the incompressible assumption reasonable? Explain.

As shown in Fig. P8.82, a standard household water meter is incorporated into a lawn irrigation system to measure the volume of water applied to the lawn. Note that these meters measure volume, not volume flowrate. (See Video V8.16.) With an upstream pressure of p1 = 50 psi the meter registered that 120 ft3 of water was delivered to the lawn during an on cycle. Estimate the upstream pressure, p1, needed if it is desired to have 150 ft3 delivered during an on cycle. List any assumptions needed to arrive at your answer.

A fan is to produce a constant air speed of 40 m/s throughout the pipe loop shown in Fig. P8.83. The 3-m-diameter pipes are smooth, and each of the four 90 elbows has a loss coefficient of 0.30. Determine the power that the fan adds to the air.

Air flows in a horizontal 100-ft-long, 24-in. 24-in. duct at the rate of 5000 ft3 /min. The air then flows through an expansion into 200 ft of 36-in. 36-in. duct. The expansion has a loss coefficient of 0.80, based on the higher inlet velocity. Calculate the static pressure change across the expansion and the static pressure loss across the entire duct system. The duct is made of galvanized sheet metal. Use a constant air density of 0.0024 slug/ft3 .

The turbine shown in Fig. P8.85 develops 400 kW. Determine the flowrate if (a) head losses are negligible or (b) head loss due to friction in the pipe is considered. Assume f = 0.02. Note: There may be more than one solution or there may be no solution to this problem.

Water flows from the nozzle attached to the spray tank shown in Fig. P8.86. Determine the flowrate if the loss coefficient for the nozzle (based on upstream conditions) is 0.75 and the friction factor for the rough hose is 0.11.

Water flows through the pipe shown in Fig. P8.87. Determine the net tension in the bolts if minor losses are neglected and the wheels on which the pipe rests are frictionless.

When the pump shown in Fig. P8.88 adds 0.2 horsepower to the flowing water, the pressures indicated by the two gages are equal. Determine the flowrate. Length of pipe between gages = 60 ft Pipe diameter = 0.1 ft Pipe friction factor = 0.03 Filter loss coeffi cient = 12

The pump shown in Fig. P8.89 adds 25 kW to the water and causes a flowrate of 0.04 m3 /s. Determine the flowrate expected if the pump is removed from the system. Assume f = 0.016 for either case and neglect minor losses.

The vented storage tank shown in Fig. P8.90 is used to refuel race cars at a race track. A total of 40 ft of steel pipe (I.D. = 0.957 in.), two 90 regular elbows, and a globe valve make up the system. Calculate the time needed to put 20 gal of fuel in a car tank. The pressures, p2 and p1, are equal, the connections are threaded, and the fuel has the properties of 68 F normal octane ( = 8.31 106 ft2 /s).

Gasoline is unloaded from the tanker truck shown in Fig. P8.91 through a 4-in.-diameter rough-surfaced hose. This is a gravity dump with no pump to enhance the flowrate. It is claimed that the 8800-gallon capacity truck can be unloaded in 28 minutes. Do you agree with this claim? Support your answer with appropriate calculations.

Calculate the water flow rate in the system shown in Fig. P8.92. The piping system includes four gate valves, two half-open globe valves, fourteen 90 regular elbows, and 250 ft of 2-in. schedule 40 commercial steel pipe (with an actual inside diameter of 2.067 in.). Assume threaded connections and a square-edged pipe entrance.

The pump shown in Fig. P8.93 delivers a head of 250 ft to the water. Determine the power that the pump adds to the water. The difference in elevation of the two ponds is 200 ft.

For the standpipe system shown in Fig. P8.94, calculate the flow rate for = 4.0 ft, D = 6.77 in., d = 0.125 in., and L = 48 in. The fluid is 70 F water. Assume steady flow and neglect the energy loss in the entrance nozzle. The pipe is commercial steel.

Water flows through two sections of the vertical pipe shown in Fig. P8.95. The bellows connection cannot support any force in the vertical direction. The 0.4-ft-diameter pipe weights 0.2 lb/ft, and the friction factor is assumed to be 0.02. At what velocity will the force, F, required to hold the pipe be zero?

Water is circulated from a large tank, through a filter, and back to the tank as shown in Fig. P8.96. The power added to the water by the pump is 200 ft lb/s. Determine the flowrate through the filter.

A thief siphoned 15 gal of gasoline from a gas tank in the middle of the night. The gas tank is 12 in. wide, 24 in. long, and 18 in. high and was full when the thief started. The siphoning plastic tube has an inside diameter of 0.5 in. and a length of 4.0 ft. Assume that at any instant of time, the steady-state mechanical energy equation is adequate to predict the gasoline flow rate through the tube. As 15 gal is 3465 in3 , the gasoline level in the tank will drop 12.0 in. You may use the gasoline level after it has dropped 6.0 in. to estimate the average gasoline flow rate. Use this flow rate to estimate the time needed to siphon the 15 gal of gasoline. Compare your answer with the answer of 190 sec found in problem 3.107, using Bernoullis equation. The siphon discharges at the level of the bottom of the gasoline tank. You may find it useful to use the Blasius equation for smooth pipes found in problem 8.45.

Estimate the time required for the water depth in the reservoir shown in Fig. P8.98 to drop from a height of 25 m to 5 m. The connections are threaded.

Sheldon and Leonard come home from a long day of studying to discover that their basement is flooded with water. They have a submersible pump for such an emergency and connect the pump discharge to a 12-ft-long garden hose, as shown in Fig. P8.99. The garden hose may be considered a smooth plastic pipe with a 1.0-in. indside diameter. If the initial water depth is 6.0 in. and the pump has an input power of 0.25 hp and an overall efficiency of 0.60, how long will it take to pump out the basement? The pump inlet piping length is negligible, and the garden hose outlet is 7.0 ft above the basement floor.

A company markets ethylene glycol antifreeze in halfgallon bottles. A machine fills and caps the bottles at a rate of 60 per minute. The 68 F ethylene glycol ( = 69.3 lbmft3 , v = 1.93 104 ft2 /s) is pumped to the machine from a tank 36 ft away. The pressure at the discharge of the pump is 35 psig, and the pressure at the inlet to the filling machine must be at least 15 psig. Determine the diameter necessary for drawn copper pipe. The pipe has no elevation change.

A certain process requires 2.3 cfs of water to be delivered at a pressure of 30 psi. This water comes from a large-diameter supply main in which the pressure remains at 60 psi. If the galvanized iron pipe connecting the two locations is 200 ft long and contains six threaded 90 elbows, determine the pipe diameter. Elevation differences are negligible.

Water is pumped between two large open reservoirs through 1.5 km of smooth pipe. The water surfaces in the two reservoirs are at the same elevation. When the pump adds 20 kW to the water, the flowrate is 1 m3 /s. If minor losses are negligible, determine the pipe diameter.

Determine the diameter of a steel pipe that is to carry 2000 gal/min of gasoline with a pressure drop of 5 psi per 100 ft of horizontal pipe.

Water is to be moved from a large, closed tank in which the air pressure is 20 psi into a large, open tank through 2000 ft of smooth pipe at the rate of 3 ft3 /s. The fluid level in the open tank is 150 ft below that in the closed tank. Determine the required diameter of the pipe. Neglect minor losses.

A commercial steel flow channel in a heat exchanger has an equilateral triangle cross section with each side measuring 5.0 in. and a length measuring 96.0 in. Water at 60 F flowing through the channel has a pressure loss of 0.10 psi. Find the water flow rate.

Rainwater flows through the galvanized iron downspout shown in Fig. P8.106 at a rate of 0.006 m3 /s. Determine the size of the downspout cross section if it is a rectangle with an aspect ratio of 1.7 to 1 and it is completely filled with water. Neglect the velocity of the water in the gutter at the free surface and the head loss associated with the elbow.

Repeat Problem 8.106 if the downspout is circular.

For a given head loss per unit length, what effect on the flowrate does doubling the pipe diameter have if the flow is (a) laminar, or (b) completely turbulent?

It is necessary to deliver 270 ft3 /min of water from reservoir A to reservoir B, as shown in Fig. P8.109. The connecting piping consists of four fully open gate valves, twelve regular 90 elbows, one swing check valve, two fully open globe valves, and 3000 ft of commercial steel pipe. Find the minimum diameter for steel pipe needed to obtain this flow rate. All fittings and valves have flanged connections. Assume a square-edged entrance.