How to Calculate Vacuum Tank Stress

Fuel truck trailers, large backyard propane tanks and even barbeque grill propane tanks are all examples of vacuum tanks.
••• Propane Tank image by John Walsh from

The American Society of Mechanical Engineers (ASME) maintains the technical standards for the maximum allowable stress on the walls of a pressure vessel, such as a vacuum tank. The formulas from Section VIII, Division 1 of ASME codes calculate the value using the maximum allowable working pressure inside the tank and incorporate a safety factor of four. To calculate actual vacuum tank stress for a given working pressure, use that pressure in the calculation and multiply the final result by four.

    Divide the working pressure by twice the joint efficiency. For an example, with a working pressure of 90 psi and a joint efficiency of 0.9, the result is 50.

    Divide the tank diameter by the wall thickness. For this example, 60 inches divided by 0.6 inches yields 100.

    Add 0.2 to the previous result. Continuing with the previous numbers, 100 plus 0.2 is 100.2.

    Multiply the results from the previous steps together to get the maximum allowable tank stress, if 100 psi was the maximum working pressure. With the example numbers, the result is 5,010 psi.

    Multiply the previous result by four to remove the safety factor and find the actual vacuum tank stress. The result in this case is 20,040 psi.

    Things You'll Need

    • Wall thickness, excluding corrosion allowance, in inches
    • Working pressure, in psi
    • Inside tank diameter, excluding corrosion allowance, in inches
    • Joint efficiency


    • This calculation is for ellipsoidal tanks, the most common shape for production facility vessels. The calculations for cylindrical, hemispherical and conical vessels differ slightly.

Related Articles

How to Calculate Working Pressure
How to Convert Gas Pressure to BTU
How to Convert mm Hg to in Hg
How to Calculate Hydraulic Cylinder Tonnage
How to Calculate Allowable Stress in Steel
How to Fill a Tractor Tire
How to Calculate Working Pressure
How to Convert CV to GPM
How to Convert MPa to N/mm^2
How to Calculate Hydraulic Press Force in Tons
How to Calculate Pneumatic Cylinder Force
How to Find Relative Barometric Pressure
How to Calculate Flow Rate With Pipe Size and Pressure
Cub Cadet Model 1330 Specifications
How to Calculate Smys
How to Calculate Heat Loss During Pipeline Depressurization
How to Calculate Static Head
How Does a DP Cell Work?
How to Figure GPM Water Flow on an Existing Chiller