WORLD FOR CIVIL

Statics & Strength of Materials

Topic 7.6b: Pressure Vessels - Problem Assignment 2

1. Copper water pipe in a house is 1.5 inches in diameter with 1/16 inch walls. The allowable tensile stress in the copper is 8000 psi. Determine the maximum pressure that the pipes can withstand. (667 psi)

2. A plastic garden hose has an inside diameter of 3/4 inch and a wall thickness of 3/16 inch. Determine the stress in the plastic when the hose is filled with water at 50 psi. (200 psi.)

3. Determine the speed of the water in the hose in problem 2 if it is used to fill a five gallon pail in one minute. (one gallon is 231 cubic inches) Express the speed in feet per second and convert to miles per hour if you can. (3.65 ft/sec = 2.49 mi/hr)

4. Process steam is generated at a central plant and distributed to various buildings in a city. The steam is at a temperature of 300 Celsius which has a pressure of 1246 psi. The steam is transferred in an 18 inch SA-202 chrome-magnesium silicon steel pipe having an allowable tensile stress of 15,000 psi. Determine the minimum thickness of the pipe where wall thickness is given in sixteenths of an inch. (3/4 in.)

5. Determine the maximum pressure of gas that is stored in a spherical container 80 feet in diameter made of SA-515-55 carbon-silicon steel having an allowable tensile stress of 11,000 psi.[P = 45.8 lb/in³ * (t in.)] (If t = 1", P = 45.8 psi)

6. Determine the thickness necessary in a steel silo (Harvester or similar) that is 80 feet tall. The maximum allowable pressure in the steel is 15,000 psi. The silo is 16 feet in diameter. Silage has the same density as water (62.4 pounds per cubic foot) and the pressure in a liquid is equal to the weight density of the liquid times the depth of the liquid. Give the thickness to the closest sixteenth of an inch. (1/4 in.)

7. A water tank is 60 feet in diameter and 45 feet high. It is made of 1/2 inch steel plate with single cover plate riveted joints. Determine the number of 3/4 inch diameter rivets needed to secure the joint. Assume that the allowable tensile strength of the steel is 15,000 psi. and that the allowable shear stress in the rivets is 12,000 psi. [Hoop stress in steel ~ 15,000 psi (depends a little on assumptions), F = Stress * A = 4.05 x 10⁶ lb, f/rivet = 5300 lb/rivet; # rivet/vertical seam = 764 x 2 =1528]

8. An air compressor used for a nail gun has a diameter of 8 inches and is charged to a pressure of 250 psi. The tank is made of welded 1/8 inch steel. Determine the tensile stress in the tank. The ends of the tank are welded to the cylindrical body. Determine the force acting on the tank ends that the weld must withstand. [ hoop = 8000 psi; Fend = 12, 570 lb]

9. A propane tank used for home heating has a diameter of 4 feet. The allowable tensile stress in the steel of the tank is 12,000 psi. Determine the required thickness of the tank. Propane has the following vapor pressures. [ t _1atm = .0294 in; t _40atm = 1.176 in]

P T
1 atm, -40 F
2 atm, -14 F
5 atm, 34.5 F
10 atm, 80 F
20 atm, 137 F
40 atm, 203 F