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In construction and home improvement, pipes are not always used to transport liquids or gases. Often they act as a building material – to create a frame for various buildings, supports for sheds, etc. When determining the parameters of systems and structures, it is necessary to calculate the different characteristics of its components. In this case, the process itself is called pipe calculation, and it includes both measurements and calculations.
Why do we need pipe parameters calculations
In modern construction, not only steel or galvanized pipes are used. The choice is already quite wide – PVC, polyethylene (HDPE and PVD), polypropylene, metal-plastic, corrugated stainless steel. They are good because they do not have as much mass as steel counterparts. Nevertheless, when transporting polymer products in large volumes, it is desirable to know their mass in order to understand what kind of machine is needed. The weight of metal pipes is even more important – delivery is calculated by tonnage. So it is desirable to control this parameter.
It is necessary to know the area of the outer surface of the pipe for the purchase of paint and heat-insulating materials. Only steel products are painted, because they are subject to corrosion, unlike polymer ones. So you have to protect the surface from the effects of aggressive environments. They are used more often for the construction of fences, frames for outbuildings (garages, sheds, gazebos, change houses), so that the operating conditions are difficult, protection is necessary, because all frames require painting. This is where the surface area to be painted is required – the outer area of uXNUMXbuXNUMXbthe pipe.
When constructing a water supply system for a private house or cottage, pipes are laid from a water source (well or well) to the house – underground. And still, so that they do not freeze, insulation is required. You can calculate the amount of insulation knowing the area of the outer surface of the pipeline. Only in this case it is necessary to take material with a solid margin – the joints should overlap with a substantial margin.
The cross section of the pipe is necessary to determine the throughput – whether this product can carry the required amount of liquid or gas. The same parameter is often needed when choosing the diameter of pipes for heating and plumbing, calculating pump performance, etc.
Inner and outer diameter, wall thickness, radius
Pipes are a specific product. They have an inner and outer diameter, since their wall is thick, its thickness depends on the type of pipe and the material from which it is made. The technical specifications often indicate the outer diameter and wall thickness.
Having these two values, it is easy to calculate the inner diameter – subtract twice the wall thickness from the outer: d = D – 2 * S. If you have an outer diameter of 32 mm, a wall thickness of 3 mm, then the inner diameter will be: 32 mm – 2 * 3 mm = 26 mm.
If, on the contrary, there is an inner diameter and wall thickness, but an outer one is needed, we add double the thickness of the stack to the existing value.
With radii (denoted by the letter R) it is even simpler – this is half of the diameter: R = 1/2 D. For example, let’s find the radius of a pipe with a diameter of 32 mm. We just divide 32 by two, we get 16 mm.
What to do if there is no pipe technical data? To measure. If special accuracy is not needed, a regular ruler will do; for more accurate measurements, it is better to use a caliper.
Pipe Surface Area Calculation
The pipe is a very long cylinder, and the surface area of the pipe is calculated as the area of the cylinder. For calculations, you will need a radius (internal or external – depends on which surface you need to calculate) and the length of the segment that you need.
To find the lateral area of the cylinder, we multiply the radius and length, multiply the resulting value by two, and then by the number “Pi”, we get the desired value. If desired, you can calculate the surface of one meter, it can then be multiplied by the desired length.
For example, let’s calculate the outer surface of a piece of pipe 5 meters long, with a diameter of 12 cm. First, calculate the diameter: divide the diameter by 2, we get 6 cm. Now all values u6bu0,06bmust be reduced to one unit of measurement. Since the area is considered in square meters, we convert centimeters into meters. 2 cm = 3,14 m. Then we substitute everything into the formula: S = 0,06 * 5 * 1,884 * 2 = 1,9 m2. If you round up, you get XNUMX mXNUMX.
Weight calculation
With the calculation of the weight of the pipe, everything is simple: you need to know how much a running meter weighs, then multiply this value by the length in meters. The weight of round steel pipes is in the reference books, since this type of rolled metal is standardized. The mass of one linear meter depends on the diameter and thickness of the wall. One point: the standard weight is given for steel with a density of 7,85 g / cm2 – this is the type that is recommended by GOST.
In table D – outer diameter, nominal diameter – inner diameter, And one more important point: the mass of ordinary rolled steel, galvanized 3% heavier, is indicated.
How to Calculate Cross-Sectional Area
If the pipe is round, the cross-sectional area must be calculated using the circle area formula: S uXNUMXd π * R2. Where R is the radius (internal), π is 3,14. In total, you need to square the radius and multiply it by 3,14.
For example, the cross-sectional area of a pipe with a diameter of 90 mm. We find the radius – 90 mm / 2 = 45 mm. In centimeters, this is 4,5 cm. We square it: 4,5 * 4,5 u2,025d XNUMX cm2, substitute in the formula S = 2 * 20,25 cm2 = 40,5 cm2.
The sectional area of a profiled pipe is calculated using the formula for the area of a rectangle: S = a * b, where a and b are the lengths of the sides of the rectangle. If we consider the section of the profile 40 x 50 mm, we get S = 40 mm * 50 mm = 2000 mm2 or 20 cm2 or 0,002 m2.
How to calculate the volume of water in a pipeline
When organizing a heating system, you may need such a parameter as the volume of water that will fit in the pipe. This is necessary when calculating the amount of coolant in the system. For this case, we need a formula for the volume of a cylinder.
There are two ways: first calculate the cross-sectional area (described above) and multiply it by the length of the pipeline. If you count everything according to the formula, you will need the inner radius and the total length of the pipeline. Let’s calculate how much water will fit in a system of 32 mm pipes 30 meters long.
First, let’s convert millimeters to meters: 32 mm = 0,032 m, find the radius (halve) – 0,016 m. Substitute in the formula V = 3,14 * 0,0162 * 30 m = 0,0241 m3. It turned out = a little more than two hundredths of a cubic meter. But we are used to measuring the volume of the system in liters. To convert cubic meters to liters, you need to multiply the resulting figure by 1000. It turns out 24,1 liters.