THIN CYLINDERS AND SPHERES 



- 1600 , 



P= 86,670 -1386, () 



where P = collapsing pressure in pounds per square inch, 



d = outside diameter of tube in inches, 

 t = thickness of wall in inches. 



Formula (A} should be used for P< 581, or-< 0.023. 

 Formula (B) should be used for values greater than these. 



109. What external pressure will collapse a steel tube whose out- 

 side diameter is 6 inches and thickness of wall 0.180 inch? 



110. Find the exterior pressure that will collapse a steel tube 8| 

 inches outside diameter and thickness of wall 0.180 inch. 



111. Determine the internal and external pressures that will re- 

 spectively rupture and collapse a steel tube 8 inches outside diameter 

 and 0.20 inch thick. 



112. What interior and exterior pressures will respectively rupture 

 and collapse a steel tube 0.30 inch thick and 10 inches outside 

 diameter? 



113. What thickness of wall should a 4-inch tube have in a fire- 

 tube boiler in order to withstand a working pressure of 200 pounds 

 per square inch, with a factor of safety of 6 ? 



114. In a fire-tube boiler the tubes are of steel, 2 inches external 

 diameter and J inch thick. What is the factor of safety for a working 

 pressure of 200 pounds per square inch? 



115. Find the exterior pressure to collapse a wrought-iron tube 

 4 inches outside diameter and 0.20 inch thick. What should be the 

 thickness for this tube under a steam pressure of 150 pounds per 

 square inch with a factor of safety of 6 ? 



116. What external pressure can a wrought-iron pipe 3 inches out- 

 side diameter and \ inch thick safely sustain and be secure against 

 shocks? 



117. Find the thickness of a boiler tube 3 inches outside diameter 

 and exposed to an external steam pressure of 150 pounds per square 

 inch for a factor of safety of 10. 



