Pipes are generally used for transportation of various liquid or gaseous materials. In terms of geometry this industrial product in most cases represents a hollow cylinder therefore when there is a need to calculate the area of its surface, it is possible to make it with use of the corresponding mathematical formulas.
Instruction
1. If it is required to find the full surface area of a pipe, then it is necessary to consider thickness of its walls. You will need to calculate and put the areas of external and internal side surfaces and also a similar indicator for both faces. For this purpose by means of a caliper, a ruler, centimeter or any other measuring tool determine the external diameter (D), thickness of a wall (w) and length (l) of a pipe.
2. Calculate the area of an outer surface. If to present it in development, then it will have the rectangle form, one of the parties of which is equal to pipe l length. Determine the size of other party by multiplication of external diameter of D by Pi's number is a formula of calculation of length of a circle. Multiply the received values and you receive the area of an outer surface of a pipe: l*π*D.
3. Calculate the area of an internal surface. The formula will be similar received on the previous step, but with replacement of external diameter by internal. Calculate it, having taken away from external the doubled wall thickness: D-2*w. Make the relevant amendment to a formula: l*π * (D-2*w).
4. Determine the area of face surfaces of a pipe - they can be presented rings, with known external and internal diameters. The surface area of such geometrical figure is calculated by the work of number of Pi on the difference of the squared radiuses (half of diameter): π * (D/2)²-((D-2*w)/2)²) = π * (D²/4-(D/2-w)²) = π * (D²/4-D²/4+D*w-w²) = π * (D*w-w²).
5. Put the received values of the areas of all four surfaces: l*π*D + l*π * (D-2*w) + 2*π * (D*w-w²). Substitute the values of diameter, length and wall thickness measured in the first step in the made formula and calculate the required area of a full surface of a pipe. If necessary to calculate only the size of the external or internal areas, just exclude from this formula unnecessary composed.