For a construction problem like this, rounding pi to 3. concrete pipe supplier for copies of specific reports. If you were to obtain circumference from a sphere based on surface area, for instance, the formula would be (after much simplification) C=8pi*r, which is 4 times bigger than 2pi*r. ZEP drain defense liquid pipe build up remover clears clogs in stopped drains and helps prevent future clogs. 944 is 12" of pipe multiplied by the 3. rounded equivalents of the inch dimensions). If we solve for C in terms of r, we get We can then substitute this value of r into the formula for the area: If the cirlcle has an area of then we need to find a way to determine the diameter of the circle. Female Threads: Measure top diameter of thread at "B"; Find figure nea rest this dimension in column 1 or 2 of chart. A Complete Guide to Pipe Sizes and Pipe Schedule – Free Pocket Chart Standardization of wrought steel Pipe schedule and pipe sizes begin with mass production era. Dimensions, weight and thickness of pipes schedule 80. towards the outside of the curve, is the product of the pressure by the cross-section multiplied by the curvature. Includes all equations (formula). If your row has both a pipe size and a tube size, pick either one; the actual insulation will be the same. Jan 18, 2017 · Pipe Fittings In Hindi - 11 Type of Pipe Fittings हिंदी में - Duration: 6:58. (looks like bendy. Round pipe: A round steel pipe 0. Where C is the circumference and π=3. 14 will do for our calculations. Pipe Diameter and Circumference for Industrial Softeners and Filters Chart. The formula for the circumference of a circle is the same. 375” actual) pipe with a ¾” high welded helical solid fin of 12 gauge thickness with 6 fins per inch has an outside surface area of 8. Measure the diameter of the object and then use the formula to find the circumference. For thin thickness pipe thickness are checked by screw gauge. If you wish to calculate the properties of a three-dimensional solid, such as a sphere, cylinder or cone, it's best to use our volume calculator. To Find The Outside Circumference Of A Pipe, The Outside Diameter Of The Pipe By 3. 6802 x wall thickness x (diameter - wall thickness). Jul 18, 2012 · Diameter is the distance ACROSS the circle, it's formula is: D = 2R (Diameter is 2 times the Radius) Circumference is the distance AROUND the circle. But many times, custom elbow angles are required at site which should be cut from standard 45° or 90° elbows. So, without wait, you can get this spreadsheet from here. Nov 03, 2014 · pipe cutting saw for 6” to 60” pipe November 3, 2014 An air-powered saw that features a self-centering track system, pre-sized for pipe from 6” to 60” dia. The design tables for PVC and ductile iron pipe were based on the outside pipe diameters specified in the AWWA C150 standards for ductile iron pipe. 4 pounds per cubic foot. 56\, =\, 2\pi R\) Letting \(\displaystyle \pi\) equal 3. But in the same circle, arcs have the same ratio to one another as the central angles they subtend. It has an inside pressure 0. 14 "X" Dimension of Standard Chart 10 CHART NO. 05 W/m·K and a thermal conductance of 10 W/m 2 ·K at the outer surface. The Circumference of a Circle As with triangles and rectangles, we can attempt to derive formulas for the area and "perimeter" of a circle. A 2 = π r 2 2. They unite two heater stages in one single shell and replace two heaters arranged in a row. Water Pressure Equations, Conversions, Formulas, and Calculations: Kilograms per square centimeter x 14. 10 cm 6 cm. The diameter is the distance from one side of the pipe to the direct opposite side of the pipe. Hudson's formula (4) is one of only two circumference formulas quoted in the Handbook of Bronshtein and Semendyayev. Gas Line Pipe Measurement Chart Pipe Circumference Pipe Size (measurement around pipe) (use to order). intumescent pvc pipe wrap Firewerx Intumescent Pipe Wrap is used to stop the spread of smoke and fire along services that pass through compartment walls and floors. Formulas of perimeter Volume. Be sure to only add similar units. Is there any formula or formula name I can. The diameter is the longest chord that runs through the center of the circle. This ratio is called π or pi, and you can approximate it as 3. For this example, let us say the measurement is 6 inches. Carbon Pipe Weight Calculator, Calculator for Seamless steel pipes - circular, structural steel weight calculator, pipe weight calculator, pipe weight calculation formula in mm, how to calculate weight of pipe in kg/m, ms square tube weight calculator. Angles in a circle. The exact formula uses a lot more math, needs at least a good scientific calculator, is long to do by hand and has little gain on precision. 13 Inches Divided into Feet 9 CHART NO. Infant Growth Charts - Baby Percentiles Overtime Pay Rate Calculator Salary Hourly Pay Converter - Jobs Percent Off - Sale Discount Calculator Pay Raise Increase Calculator Linear Interpolation Calculator Dog Age Calculator Ideal Gas Law Calculator Gain On Sale Calculator Circle Equations Calculator Geometric Shapes Calculator Triangle. Rather strangely, the perimeter of an ellipse is very difficult to calculate! There are many formulas, here are some interesting ones. You can also select units of measure for both input data and results. Since we're talking about very small variations, any reasonable method of determining wheel size is good enough. Present rounded form to the. Circle Formulas 02 9 Terms. 9736 3 segments ( arcs) = 21. Calculation of pipes are based on a formula V=π*R1*R1*L Calculation of the surface area of the pipes are based on a formula P=2*π*R2*L R1 - inner radius pipes R2 - outer radius pipes L - pipe length. 1415926535897932384 but = 3. Preparing the pipe The outer surface of the pipe must be cleaned and pre-treated in the same way as for puddle flanges 32 to 315 mm diameter. Collapse ratings on API tubulars are derived from four different equations based on the outside diameter / thickness ratio and the yield strength of the pipe. Then tap or click the Calculate button. Formulas and Properties of a Rhombus Circle, disk, segment, sector. From the PIPE dimensions after their conversion to millimeters, is created the first preferred line of the outer diameter of steel tube (1st line is in EN 10220, DIN 2448, etc. To figure out the pipe weight per foot, the wall thickness and diameter of the pipe are required. " Nominal" refers to pipe in non-specific terms and identifies the diameter of the hole with a non-dimensional number (for example - 2-inch nominal steel pipe" consists of many varieties of steel pipe with the only criterion being a 2. The entire formula for the surface area of a cylinder is 2 π r 2 + 2 π r h. The rubber gaskets are manufactured to conform to the requirements of ASTM F-477. Many people assume pipe size is the outer diameter of the pipe—but "pipe size" actually refers to what is called "nominal diameter. The imperial formula is: Wt/Ft = 10. With this calculator tool, you can calculate the Outer Radius (R), Inner Radius (r), Witdth or Thickness (w), Area (A), Inner Circumference (ic) or Outer Circumference (oc), and even the Central Area (ca). You need to calculate the path taken by the centre of the ‘elbow’ and multiply that by the circumference of the cross-section, just like you would with a straight cylinder. Pipe sizes do not refer to any physical dimensions. 1 litres/sec (20. The pipe radial strain is assumed to be small and is neglected. To calculate area and circumference we must know the radius of circle. Formulas & Data SHAPE WEIGHT FORMULAS. Mar 12, 2015 · A length of metal pipe has a circumference of 2. ) Width (in. 14 10 cm x 3. So what is the circumference? Well, we know the circumference is equal to two pi times the radius. circumference definition: The circumference is defined as the distance around something round or rounded, especially the distance around the edge of a circle. Inner circumference of an annulus: C 2 = 2 π r 2. About how many feet of fencing are needed to go around the pool path? Use 3. Where: Angle = the included angle between the outside lines of the main development. The formula for the circumference of a circle: C = 2πR = πD. Circumference to Diameter Calculator. The String Method. 625″ – while 1¼″ tube has a true 1. ) Width (in. The radius is half the diameter. Trim the paper at the top and bottom to match the shape of the can. Calculations are based on algebraic manipulation of these standard formulas. S Circle, S. Just enter the value of the circumference. Calculating Area and Volume of Ponds and Tanks Good fish farm managers must know the area and volume of all ponds and tanks. 142 If you know the area If you know the area of a circle, the diameter can be found using the formula where: A is the area of the circle. For those of you doing real basic design or engineering for home or work, here's an easy way to determine wall thickness of steel pipe. For example, a 3/4" NPT pipe thread has an outside diameter of 1. Take E = 180 GPa and = 0. 8 Sch 40 Galvanized 12 12. You can demonstrate this by taking a piece of stiff wire and doing just that: bring the ends of the wire together end a circle shape will be formed. This circumference to diameter calculator is used to find the diameter of a circle given its circumference. You will notice the calculated result is longer. Eratosthenes was the. American Piping Products. This relationship is expressed in the following formula:. The best and most advanced online metal weight calculation site in the field. Perimeters - Cool Math has free online cool math lessons, cool math games and fun math activities. Find the radius, circumference, and area of a circle if its diameter is equal to 10 feet in length. The Scope of ASTM A53 states, “Pipe ordered under this specification is intended for mechanical and pressure applications and is also acceptable for ordinary uses in steam, water, gas and air lines”. Answer / shreebatsa panda we have to consider d design stresses then only we vl apply. Pipe Equations - Calculate cross-sectional areas, weight of empty pipes, weight of pipes filled with water, inside and outside surface areas Radius of Gyration in Structural Engineering - Radius of gyration is used to describe the distribution of cross sectional area in a column around its centroidal axis. Calculator is designed for simple and quick calculation of round pipe internal diameter based on known volume or mass flow rate and desired stream velocity trough pipe. If you know the diameter If you know the diameter of a circle, the circumference can be found using the formula where: D is the diameter of the circle. The clay pipe in the ground is 5 inches OUTSIDE DIAMETER. 1832 inches. This formula use the constant pi and radius. The maximum hoop stress always occurs at the inner radius or the outer radius depending on the direction of the pressure gradient. This constant ratio is denoted by the Greek letter $$\pi $$. 6" Leg length on each side (straight section). ZEP drain defense liquid pipe build up remover clears clogs in stopped drains and helps prevent future clogs. 14 ) by the diameter of the circle. ) 3) Required Thickness for Bending Pipe. As usual, this spreadsheet is uploaded at dropbox. How do you find the circumference of a circle? Finding Circumference Using Diameter As you learned earlier, the ratio of the circumference to the diameter is the same for all circles. We know the formula to find the perimeter of the circle if the diameter is given, namely π· D. Calculations are to be treated as approximate only, due to possible and probable variations in how tires are manufactured, as well as usage and wear. The circumference, which is the outside edge of the circle. Diameter Formula Diameter is defined as the line passing through the center of a circle having two extremes on the circumference of a circle. Calculate the circumference of a circle with a diameter of 10 inches. Schedules are provided as a means of standardization of pipe sizes. The diameter, which joins the circumference through the centre of the circle. 10: free body diagram of a cylindrical pressure vessel As with the sphere, the radial stress varies from p at the inner surface to zero at the outer surface, but again is small compared with the other two stresses, and so is taken to be r 0. Please note Howard Sutherland's words of wisdom! To find the correct spoke length when building a wheel, you need dimensions of the rim and hub. i want to add a new pipe dia in my project. download circumference of a bottle cap free and unlimited. 1, 1977 with allowances for connections and fittings reduces these working pressures approx. Circumference 3. Precision Digital Linear Tape, Diameter Tape, Inside Diameter Tape, Precision Measuring Tape, Circumference Tape, Precision Digital Tapes by Pi Tape Texas, LLC. 141592 Area of Circle: area = PI r 2. DIAMETER: the width of a circle (through center). gripping the closure uniformly around its complete. Actual Inside Diameter (Inches) Nominal Outside Pipe Corrugated “SDR” means standard dimension ratio and is the ratio of outside. The formula used to calculate circumference to diameter is C=pie x diameter, where pie =22/7 or 3. (a) Undeveloped hot air at T,0-600 K meets the pipe moving at U00-60 쯩 in the same direction as the water down the pipe. About how many feet of fencing are needed to go around the pool path? Use 3. Unlike triangles, rectangles, and other such figures, the distance around the outside of the circle is called the circumference rather than the perimeter-the concept, however, is essentially the same. To find the circumference of the manhole cover, use the formula: Circumference = Pi X diameter. For thin thickness pipe thickness are checked by screw gauge. An example of an annulus is the area of a washer and the area of a concrete pipe. If your fan system has developed a squeak the root cause could be due to the belt wearing out, dirty pulleys, belt is too loose, incorrect belt type, poor belt quality, oil on the belts, a bad bearing in a pulley, worn idler pulley, motor going bad, or belt misalignment. 5 inches pi*d = 65. 69*(OD - Wall Thickness)*Wall Thickness Outer Diameter (i. It must be. per linear foot; whereas the same bare pipe has an outside surface area of only. c Circumferential stress in a thin-walled cylindrical pressure vessel (7. In this series, it is the most common material or steel plate grade. This is an example of an Archimedean Spiral, otherwise known as an arithmetic spiral, where the arms get bigger by a constant amount for each turn. PVC Pipe Size Dimensions Chart FORMUFIT products are compatible with most Schedule-based PVC pipe systems. Surface area of the annulus (the gray shaded area) A 0. pipe sections with red arrows are of radius R/2. 141592 Area of Circle: area = PI r 2. Circle Formulas 02 9 Terms. Structural pipe is a round hollow section and generally used as structural columns. Generalizations for 2D In two dimensions, a curve can be expressed with the parametric equations and. ceaŽ 02 O SQUARE WHERE I 04 d4 04 - d4 02 + side side shori sh0ft side intetaaf 1. 8 Sch 40 Galvanized 8 8. γ is surface energy. Volume of hollow containers - cylinder and cone How you can find the volume of a hollow cylinder and a cone using the formula of volume of prism and pyramid? Example: 1. Table Surface Area of Pipe Example for pipe Diameter 1 inch (outer diameter 33. 13 Inches Divided into Feet 9 CHART NO. Fitter Fabricator 37,507 views. They say an ounce of prevention is worth a pound of cure, especially when it comes to drain care. Female Threads: Measure top diameter of thread at "B"; Find figure nea rest this dimension in column 1 or 2 of chart. Formulas, characterizations and properties of a cone Area. The string method (which measures the circumference of the pipe) is probably the best way to determine your pipe diameter size. how to calculate pipe outer dia and inner dia. com's Circle Calculator – Use the drop down menu to find a circle's area, circumference, or radius. 1 Sch 40 Galvanized 10 10. Pipe fitting may be done either by making close visual judgments or entirely by measurements scaled on a drawing. The maximum hoop stress always occurs at the inner radius or the outer radius depending on the direction of the pressure gradient. Relations between elements of a circle. We always used schedule 80 fitting start and end, slip (glue) to FIP (female iron pipe) thread. Circumference of a bottle cap. The expansion coefficient for stainless steel S30100 is 9. It is called a double-pipe exchanger because one fluid flows inside a pipe and the other fluid flows between that pipe and another pipe that surrounds the first. 625″ – while 1¼″ tube has a true 1. 82 Therefore 13. Formulas for Circle Circumference, Circle Area, Sphere Area, Partially Filled Sphere Area, Partially Filled Sphere Volume, Sphere Volume, Cylinder Area, Cylinder Volume For a circle, sphere and cylinder calculator click here. 1417 ----- = flat length 2 formula to find the diameter of a circle circumference x 0. 14 for mc017-2. The area of a thin annulus is calculated by multiplying the circumference of a circle multiplied by a thickness \(\displaystyle dr\). The thickness of the pipe is the distance between the outer radius R and the inner radius r. Actual Inside Diameter (Inches) Nominal Outside Pipe Corrugated “SDR” means standard dimension ratio and is the ratio of outside. All dimensions are in millimeters. Octal is a leading supplier of API 5L Steel Line Pipe, Fittings, OCTG Casing and Tubing, providing best solutions and prices for Oil and Gas industries worldwide. Find the perimeter of a square with side length 2. Butt Fusion is the most important and widely used method of connection for HDPE pipes larger than 110 mm. light,medium & heavy pipe. The following figure gives the formula for the volume of sphere. If you don't have the radius, divide the circumference of the circle by π to get the diameter. It must be. 4 m internal diameter x 10. 1416) 40 × 40 × 3. 1415 usually gives you plenty of precision. If you were to obtain circumference from a sphere based on surface area, for instance, the formula would be (after much simplification) C=8pi*r, which is 4 times bigger than 2pi*r. November 12, 2019 ACPA Project Achievement Runner-Up Winners Whether it’s to handle standard drainage, unusually heavy loads or wide crossings, reinforced concrete. (Yields When Using Sheet to Insulate Large Diameter Pipe) Note: Rolls can offer better yield than sheet. The parts of a circle relevant to a pipe bending are: The circumference - the outer rim of the circle. One side of the blade is a regular 10ft tape measure, the reverse side is the pipe diameter tape measure. For example, a 3/4" NPT pipe thread has an outside diameter of 1. towards the outside of the curve, is the product of the pressure by the cross-section multiplied by the curvature. Remember to include your unit of measure – in this case, inches – when you write down your answer. Then, click on Calculate. CIRCUMFERENCE: the edge of a circle or the distance around a circle. please tell me in details how to calculate. This stress tends to open-up the pipe wall and is caused by internal pressure. Pi is typically estimated as 3. The Ellipse Circumference Calculator is used to calculate the approximate circumference of an ellipse. Our circumference calculator provides circumference of a circle by entering its radius. Tangent and radius. Formula: Wt/Ft = (*OD - *WT) x *WT x 10. 750 inches) is heated from 68 o F to 98 o F. The example below is for a mitered elbow on 2-3/8" OD Tubing. Divide the area of the whole circle by 4. Really clear math lessons (pre-algebra, algebra, precalculus), cool math games, online graphing calculators, geometry art, fractals, polyhedra, parents and teachers areas too. Circumference is defined as the distance around a circle; the diameter is the straight-line distance across the circle that touches two points on its border and goes through its center. 82 Therefore 13. 3/4" into house to water heater, rest of pipe inside house, 1/2". Therefore a higher SDR indicates a thinner-walled pipe at any given diameter. Annulus Formulas in terms of radius r and π Outer circumference of an annulus: C 1 = 2 π r 1. Please explain this to me. Surface tension force acts parallel to the particle’s (bubble's) surface, and is distributed around the perimeter of the cross section, as shown by the downward arrows in the diagram above,. Circle Solver Calculator Enter the circle area, diameter, or circumference and it will solve for the other two. The clay pipe in the ground is 5 inches OUTSIDE DIAMETER. towards the outside of the curve, is the product of the pressure by the cross-section multiplied by the curvature. 90° and 45° Long Radius Elbows - ANSI B16. How to make a simple solar water heater Contents: the circumference (O/2) and the diameter of the pipe, 15mm. Formulas, characterizations and properties of a cone Area. You can measure the circumference without a formula, so if both measures are accurate, and the circle is a true circle, pi is always going to equal c/d, and thus c/d will always equal pi. model of steady conduction in the radial direction through a cylindrical pipe wall when the inner and outer surfaces are maintained at two different temperatures. what is the circumference of a bottle cap? yahoo answers. A pipe has an outside diameter of 1. using the three-wire method to measure threads the pitch diameter of a. Based on Manning's Formula, these values are equal to Q/S1/2 for full flow. For those of you doing real basic design or engineering for home or work, here’s an easy way to determine wall thickness of steel pipe. 141593, however the value 3. 2D GEOMETRY FORMULAS SQUARE s = side Area: A = s2 Perimeter: P = 4s s s RECTANGLE l = length, w = width Area: A = lw Perimeter: P = 2l +2w w l TRIANGLE b = base, h = height. A table of formulas for geometry, related to area and perimeter of triangles, rectangles, cercles, sectors, and volume of sphere, cone, cylinder are presented. When the pressure rises inside the pipe, the coupling effects cause the pipe to. Standard pipe, extra strong (x-strong) pipe and double-extra strong (xx-strong) pipe sizes, dimensions and section properties are given in the following structural steel pipe chart per Steel Construction Manual. The hoop stress, or tangential stress, is the stress around the circumference of the pipe due to a pressure gradient. The answers to the rest of my equations should be easy now. You need the total length of your pipes (see Step 2 for pipe length calculations) plus about an inch per pipe to compensate for mistakes and to allow tuning. The circle pictured here has a diameter of 10 cm. (noun) An example of circumference is the distance around the outer boundary of a circle. Program to calculate Area and Circumference based on user input. Length of Inner Spacer Ring = Circumference of Inner Ring = 2丌r (where R – Radius) = 2 X 3. Pipe sizes do not refer to any physical dimensions. where, C= circumference and π= It is constant pronounced as “pi” with the value of 22/7 or 3. When attaching to sheet metal fittings, slide the crimped end of the duct into the straight end of the fitting and secure with sheet metal screws at about 4" on center. Perimeter of an Ellipse. 141592653589793 Therefore, the circumference depends only on the size of r. **These two formulas are just two different ways of finding the same thing (circumference) because the diameter of a circle $$ =2 \cdot radius $$. 9912 which is the distance along the circumference that the points are from each other. A geometric solid tube is generally a cylinder with an end profile represented by an annulus. The Pipe Calc Elite™ is an advanced calculator designed specifically for pipe trade professionals. Pipe Burst Working Pressure Calculator Barlow's Formula. The formula for pipe load is: P y = DL + LL P y = Pipe Load, lb/in2. Saddle on (tees) Standard. Circumference of a circle = 3. A 45" x 73" pipe arch at the same slope and "n" carries about 72 cfs ( page 194). Too long a pipe thread allows the pipe to travel too far into the fitting. Where: Angle = the included angle between the outside lines of the main development. 0 revolutions per second (rev/s). 8 Sch 40 Galvanized 12 12. L - circumference. On our site you can calculate the weight of various materials on metal as close to real as possible. The formula to find the area and circumference of a circle is shown below:. Pipe Tubing. 946 m3/min). But in the same circle, arcs have the same ratio to one another as the central angles they subtend. Volume of hollow containers - cylinder and cone How you can find the volume of a hollow cylinder and a cone using the formula of volume of prism and pyramid? Example: 1. We know the formula to find the perimeter of the circle if the diameter is given, namely π· D. Doing so removes the object walls from your measurement, leaving only the space between them. RADIUS: 1/2 of the "diameter", or the distance from the center to the edge (circumference). 81 unit, the total No. 142 See also Derivation of circumference formula. The formula is: Wt/Ft = 10. It includes some tutorial information as well as circle formulas and examples. So here's the formula: Cross Sectional Area of a Cylinder = π x R2 where π is a constant (= 3. For example, a 3/4" NPT pipe thread has an outside diameter of 1. Basic Plane Geometry Circles Multiple Functions. Bath taps and sink taps. You can figure out the earth's circumference using a geometric formula that's over 2,000 years old! Contrary to popular belief, Christopher Columbus did not discover that the Earth is round. 4 and Pi value as 3. The pipe is 202" around outside perimeter. Simple-to-use and mobile friendly, this is a great tool for your pipe-buying toolbox. So, if you're dealing with a pipe that has an outside circumference of 10 inches, its outside diameter is 10 ÷ 3. Inner circumference of an annulus: C 2 = 2 π r 2. Is it the circumference of the opening you need? Linear distance is distance as if the object was along a straight line, without any care to the width or height. The pipe axes are assumed to be the principal axes of the strain tensor, therefore shear strains are not included. Really clear math lessons (pre-algebra, algebra, precalculus), cool math games, online graphing calculators, geometry art, fractals, polyhedra, parents and teachers areas too. Shop galvanized pipe in the galvanized pipe & fittings section of Lowes. Includes all equations (formula). 14 times as long as the diameter letter pi. The inside diameters are as given in Table No. Pipe is usually measured by NOMINAL PIPE SIZE (NPS). 87mm (Based on using the centre line of the circumference). Radian measure of angles. MANUFACTURER shall mark the measurements on the pipe, at the points where they were taken, and use them to install the pipe in the bending. However, there are approximate formulas in terms of these parameters. Calculations are based on algebraic manipulation of these standard formulas. Use one strip of paper. Right Triangle and Pythagora's theorem Pythagora's theorem: The two sides a and b of a right triangle and the hypotenuse c are related by. Inner and Outer Diameters of Standard Pipe Insulation. Mar 06, 2012 · In India M. A 24" concrete pipe has a 30" outside diameter and a 36" precast opening. 3 (Answers 0. About eight feet of type M 1/2" nominal copper pipe. It has an inside pressure 0. Conversely, a half hour heat up requires 20 watts to heat the system. A Poisson ratio of zero is assumed in the derivation of this result; to be completely consistent, a Poisson ratio of zero may be given for the line type. The diameter is the longest chord that runs through the center of the circle. Pipe sizes do not refer to any physical dimensions. These weight calculations are based upon the theoretical weight of steel at 40. r: radius d: diameter A: Area The area of a circle is given by: A = Π ∙ r 2 or A = Π ∙ (d/2) 2 Π defines the ratio of any circle's circumference to its diameter and is approximately equal to 3. Q345B steel pipe is 16Mn steel pipe, which is one of seamless steel pipe products. Conversion Chart - Circumference to Diameter Note: The first column to the left is only approximate equivalent to the decimal figure in the next column. When bending a pipe to any radius it should be remembered that you are constructing part of a circle. Use the area formula with r/2. If you increase the radius of a circle a small amount, its area increases by adding a thin strip around the outside. Use one strip of paper. Tube Formulas in terms of radius and height, r and h: Circumference, C: generally C = 2 π r, therefore, C 1 = 2 π r 1; C 2 = 2 π r 2; Lateral Surface Area, L, for a cylinder: generally L = C * h = 2 π rh, therefore,. per linear foot. So, if you're dealing with a pipe that has an outside circumference of 10 inches, its outside diameter is 10 ÷ 3. Formulas of volume Surface Area Formulas. OD and Nominal Pipe Size. The mathematical relation between radius (or diameter) and circumference is given by the following formula: C = 2πr = πD. Calculating the Circumference of a Circle: The circumference of a circle with a known radius and can calculated using the following formula: C = 2Π(r) The constant PI (Π) can be approximated as 3. there are 3.