Introduction to Pressure Vessel Safety Awareness Tutorial
Safety - Accidents - Investigations - Inspections - Training - Instructions
Pressure Vessel Force and PressureWhat is force? Force can be described in pounds or tons. We intuitively think of force in weight which is a fair description. Is there a difference between 10-psi and 1000-psi? Yes, there is a 100-times difference in pounds. This becomes very important when a pressure vessel contains steam, air, volatile gases, compressible gas/fluid, or substances that have internal energy such that when exposed to the atmosphere the substance expands violently. Steam is a good example where there is an expansion process of 1604-times [saturated steam]. Question: Imagine a vessel with a 1-foot diameter cover that is fastened to a pressure vessel and there is 10-psi pushing outward against the cover. How much force is being applied to the cover? A) 10-psi B) 10,000-pounds C) 1,131-pounds D) 101-pounds Answer C) 1130-pounds. That is over 1/2-ton of force with only 10-psi. The point here is 10-psi can be as deadly as 1000--psi. Finally, we can never under estimate the care needed in keeping pressure vessels in top condition. Force = 10-psi x p r 2 [don’t forget to convert ] Lets try another question. A tank is 50-foot tall with atmospheric [exposed to the outside air] pressure at the top and it contains water. How much pressure [psi] is at the bottom of the tank? A.) 0-psi B.) 22-psi C.) 25-psi D.) 53-psi Answer B) 22-psi. Gradually, as we come down the tank wall the pressure increases; therefore, the thickness of the tank wall would have to increase in order to retain the water. p = g x 50-feet [don’t forget to convert & g = 62.4 lbs../ft3 ] Next: Pressure Vessels >> |