Cylinder Tonnage Calculations

To calculate the tonnage that a cylinder can provide, you must have the following values:

• Cylinder Bore (B)
• Rod Diamater (D)
• Maximum Pressure (P)

For an example, we will be using a cylinder with an 8" bore (B=8), a rod diameter of 4" (D=4), and a Max PSI of 3000 PSI

It should be noted that the cylinder will have different tonnage strengths if it is pushing or if it is pulling. The tonnage is always higher pushing, as the pressure is acting against the entire lower system of the piston, whereas when it is pulling, the pressure is acting on that area, less the area of the rod.

Pushing Tonnage

To calculate the "Pushing," or expanding tonnage,

1. Find the cross sectional area (A) of the surface. This is simply the area of the circle, so A= Pi X (B/2)^2
   • For the example, A=3.14 X (8"/2)^2 = 3.14 x 4"^2 = 3.14x 16 in^2 = 50.24 in^2
2. Multiply the cross sectional area (A) by the maximum pressure (P), so the tonnage (T)= A x P
   • For the example, T=50.24 in^2 x 3000PSI= 150720 pounds
3. Convert pounds to tons, T/2000= new T
   • 150720 lbs/2000= 75.36 Tons

Pulling Tonnage

To calculate the "Pulling," or contracting tonnage,

1. Find the cross sectional area (A) of the surface. This is area of the bore circle, minus the rod circle, so A= Pi X (B/2)^2- Pi x (D/2)^2 = Pi x ((B/2)^2-(D/2)^2))
   • For the example, A=3.14 X ((8"/2)^2-(4"/2)^2)) = 3.14 x (4"^2-2"^2)= 3.14 x (16"=4") = 3.14x 12 in^2 = 37.68 in^2
2. Multiply the cross sectional area (A) by the maximum pressure (P), so the tonnage (T)= A x P
   • For the example, T=37.68 in^2 x 3000PSI= 113040 pounds
3. Convert pounds to tons, T/2000= new T
   • 150720 lbs/2000= 56.52 Tons