Pipe diameters in inches and millimeters. Converting numbers to different number systems with solution Difference between measurement systems

The calculator allows you to convert whole and fractional numbers from one number system to another. The base of the number system cannot be less than 2 and more than 36 (10 digits and 26 Latin letters, after all). Numbers must not exceed 30 characters. To enter fractional numbers, use the symbol. or, . To convert a number from one system to another, enter the original number in the first field, the base of the original number system in the second, and the base of the number system to which you want to convert the number in the third field, then click the "Get Entry" button.

original number recorded in 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 -th number system.

I want to get a record of a number in 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 -th number system.

Get an entry

Completed translations: 1710505

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Number systems

Number systems are divided into two types: positional And not positional. We use the Arabic system, it is positional, and there is also the Roman one - it is just not positional. In positional systems, the position of a digit in a number uniquely determines the value of that number. This is easy to understand by looking at the example of some number.

Example 1. Let's take the number 5921 in the decimal number system. We number the number from right to left starting from zero:

The number 5921 can be written in the following form: 5921 = 5000+900+20+1 = 5 10 3 +9 10 2 +2 10 1 +1 10 0 . The number 10 is a characteristic that defines the number system. The values ​​of the position of the given number are taken as degrees.

Example 2. Consider the real decimal number 1234.567. We number it starting from the zero position of the number from the decimal point to the left and to the right:

The number 1234.567 can be written as follows: 1234.567 = 1000+200+30+4+0.5+0.06+0.007 = 1 10 3 +2 10 2 +3 10 1 +4 10 0 +5 10 -1 + 6 10 -2 +7 10 -3 .

Converting numbers from one number system to another

Most in a simple way transferring a number from one number system to another is the translation of the number first into the decimal number system, and then, the result obtained into the required number system.

Converting numbers from any number system to decimal number system

To convert a number from any number system to decimal, it is enough to number its digits, starting from zero (the digit to the left of the decimal point) similarly to examples 1 or 2. Let's find the sum of the products of the digits of the number by the base of the number system to the power of the position of this digit:

1. Convert number 1001101.1101 2 to decimal number system.
Solution: 10011.1101 2 = 1 2 4 +0 2 3 +0 2 2 +1 2 1 +1 2 0 +1 2 -1 +1 2 -2 +0 2 -3 +1 2 - 4 = 16+2+1+0.5+0.25+0.0625 = 19.8125 10
Answer: 10011.1101 2 = 19.8125 10

2. Convert number E8F.2D 16 to decimal number system.
Solution: E8F.2D 16 = 14 16 2 +8 16 1 +15 16 0 +2 16 -1 +13 16 -2 = 3584+128+15+0.125+0.05078125 = 3727.17578125 10
Answer: E8F.2D 16 = 3727.17578125 10

Converting numbers from a decimal number system to another number system

To convert numbers from a decimal number system to another number system, the integer and fractional parts of the number must be translated separately.

Converting the integer part of a number from a decimal number system to another number system

The integer part is translated from the decimal number system to another number system by successively dividing the integer part of the number by the base of the number system until an integer remainder is obtained, less than the base of the number system. The result of the transfer will be a record from the remains, starting with the last one.

3. Convert number 273 10 to octal number system.
Solution: 273 / 8 = 34 and remainder 1, 34 / 8 = 4 and remainder 2, 4 is less than 8, so the calculation is complete. The record from the remnants will look like this: 421
Examination: 4 8 2 +2 8 1 +1 8 0 = 256+16+1 = 273 = 273 , the result is the same. So the translation is correct.
Answer: 273 10 = 421 8

Let's consider the translation of correct decimal fractions into various number systems.

Converting the fractional part of a number from a decimal number system to another number system

Recall that a proper decimal fraction is real number with zero integer part. To translate such a number into a number system with base N, you need to consistently multiply the number by N until the fractional part is zeroed or the required number of digits is obtained. If during multiplication a number with an integer part other than zero is obtained, then the integer part is not taken into account further, since it is sequentially entered into the result.

4. Convert number 0.125 10 to binary number system.
Solution: 0.125 2 = 0.25 (0 is the integer part, which will be the first digit of the result), 0.25 2 = 0.5 (0 is the second digit of the result), 0.5 2 = 1.0 (1 is the third digit of the result, and since the fractional part is zero , the translation is complete).
Answer: 0.125 10 = 0.001 2

This article will discuss such concepts related to threaded connections as metric and inch threads. To understand the subtleties associated with a threaded connection, it is necessary to consider the following concepts:

Conical and cylindrical thread

The rod itself with applied to it tapered thread is a cone. Moreover, according to international rules, the taper should be 1 to 16, that is, for every 16 units of measurement (millimeters or inches) with increasing distance from the starting point, the diameter increases by 1 corresponding unit of measurement. It turns out that the axis around which the thread is applied and the conditional straight line drawn from the beginning of the thread to its end along the shortest path are not parallel, but are at a certain angle to each other. If it is even easier to explain, then if we have a length threaded connection was 16 centimeters, and the diameter of the rod at its starting point would be 4 centimeters, then at the point where the thread ends, its diameter would already be 5 centimeters.

rod with cylindrical thread is a cylinder, respectively, there is no taper.

Thread pitch (metric and inch)

The thread pitch can be large (or basic) and small. Under thread pitch is understood as the distance between the threads from the top of the thread to the top of the next thread. You can even measure it with a caliper (although there are special meters). This is done as follows - the distance between several vertices of the turns is measured, and then the resulting number is divided by their number. You can check the accuracy of the measurement according to the table for the corresponding step.

Nominal thread diameter

The label usually contains nominal diameter, for which in most cases the outer diameter of the thread is taken. If the thread is metric, then a regular caliper with scales in millimeters can be used for measurement. Also, the diameter, as well as the thread pitch, can be viewed from special tables.

Metric and inch thread examples

Metric thread- has a designation of the main parameters in millimeters. For example, consider an elbow fitting with an external parallel thread EPL 6-GM5. In this case, EPL says that the fitting is angled, 6 is 6 mm - the outer diameter of the tube connected to the fitting. The letter "G" in its marking indicates that the thread is cylindrical. "M" indicates that the thread is metric, and the number "5" indicates a nominal thread diameter of 5 millimeters. Fittings (of those that we have on sale) with the letter “G” are also equipped with a rubber o-ring, and therefore do not require fum tape. The thread pitch in this case is - 0.8 millimeters.

Main settings inch thread, according to the name - are indicated in inches. It can be 1/8, 1/4, 3/8 and 1/2 inch threads, etc. For example, take a fitting EPKB 8-02. EPKB is a type of fitting (in this case, a splitter). The thread is conical, although there is no reference to this with the letter “R”, which would be more literate. 8 - indicates that the outer diameter of the connected tube is 8 millimeters. A 02 - that the connecting thread on the fitting is 1/4 inch. According to the table, the thread pitch is 1.337 mm. The nominal thread diameter is 13.157 mm.

The profiles of the conical and cylindrical threads coincide, which allows fittings with conical and cylindrical threads to be screwed together.

Her Majesty Trumpet! It certainly makes our lives better. Like that:

The key characteristic of any cylindrical pipe is its diameter. It may be internal Do) and outer ( Dn). Pipe diameter is measured in millimeters, but the unit of pipe thread is inch.

At the junction of the metric and foreign systems of measurement, as a rule, the most questions arise.

In addition, really existing size inner diameter often does not match Dy.

Let's take a closer look at how we can live with this. Pipe thread dedicated to a separate article. Read also about profile pipes, which are used for the construction of structures.

Inches versus mm. Where does the confusion come from and when is a correspondence table needed?

Pipes whose diameter is indicated in inches ( 1", 2" ) and/or fractions of an inch ( 1/2", 3/4" ), are the generally accepted standard in water and water and gas supply.

What is the difficulty?

Dimension the pipe diameter 1" (how to measure pipes is written below) and you will get 33.5mm, which naturally does not coincide with the classic linear table for converting inches to mm ( 25.4mm).

As a rule, installation of inch pipes takes place without difficulty, but when they are replaced with pipes made of plastic, copper and of stainless steel a problem arises - a mismatch in the size of the designated inch ( 33.5mm) to its actual size ( 25.4mm).

Usually this fact is puzzling, but if you look deeper into the processes occurring in the pipe, then the logic of the size discrepancy becomes obvious to the non-professional. It's pretty simple - read on.

The fact is that when creating a water flow, the key role is played not by the outer, but by the inner diameter, and for this reason it is he who is used for designation.

However, the discrepancy between designated and metric inches still remains, because the internal diameter of a standard pipe is 27.1 mm, and enhanced - 25.5mm. The last value is pretty close to equality 1""=25,4 but still they are not.

The answer is that to indicate the size of pipes, a nominal diameter rounded to a standard value is used (nominal bore Dy). The value of the conditional passage is selected so that the throughput of the pipeline increases from 40 to 60% depending on the growth of the index.

Example:

The outer diameter of the pipe system is equal to 159 mm, pipe wall thickness 7 mm. The exact inside diameter will be D \u003d 159 - 7 * 2 \u003d 145 mm. With wall thickness 5 mm size will be 149 mm. However, both in the first and in the second case, the conditional passage will have one nominal size 150 mm.

In situations with plastic pipes transition elements are used to solve the problem of inappropriate sizes. If it is necessary to replace or dock inch pipes with pipes made according to real metric dimensions - copper, stainless steel, aluminum, both the outer and inner diameters should be taken into account.

Nominal bore table in inches

Table. Inner and outer diameters. Stacked water/water and gas pipelines, electro-welded straight-seam, steel seamless hot-formed and polymer pipes

Correspondence table for the diameter of the nominal bore, thread and outer diameters of the pipeline in inches and mm.

GOST- state standard used in heat - gas - oil - pipelines

ISO- diameter designation standard, used in plumbing engineering systems

SMS- Swedish standard for pipe and valve diameters

DIN/EN- the main European assortment for steel pipes according to DIN2448 / DIN2458

DU (Dy)- conditional pass

Dimension tables polypropylene pipes presented in the following article >>>

Correspondence table for the nominal diameter of pipes with international markings

Diameters and other characteristics of stainless steel pipe

Did you know?

What ingenious lamps can be assembled with your own hands from ordinary metal pipe? This is for everyone!

Which pipe is considered small - medium - large?

Even in serious sources, I had to observe phrases like: “We take any pipe of medium diameter and ...”, but no one indicates what this average diameter is.

To figure it out, you should first understand what diameter you need to focus on: it can be internal and external. The first is important when calculating the transport capacity of water or gas, and the second for determining the ability to withstand mechanical loads.

External diameters:

From 426 mm is considered large;

102-246 is called the average;

5-102 is classified as small.

As for the inner diameter, it is better to look at a special table (see above).

How to find out the pipe diameter? Measure!

For some reason, this strange question often comes to e-mail and I decided to supplement the material with a paragraph about metering.

In most cases, when buying, it is enough to look at the marking or ask the seller a question. But it happens that you need to repair one of the communication systems by replacing pipes, and initially it is not known what diameter the already installed ones have.

There are several ways to determine the diameter, but we will list only the simplest ones:

Arm yourself with a tape measure or measuring tape (women measure their waist like this). Wrap it around the pipe and record the measurement. Now, to obtain the desired characteristic, it is enough to divide the resulting figure by 3.1415 - this is the Pi number.

Example:

Imagine that in girth (circumference L) your pipe 59.2 mm. L=ΠD, resp. diameter will be: 59.2 / 3.1415= 18.85mm.

• After receiving the outer diameter, you can find out the inner one. Only for this you need to know the thickness of the walls (if there is a cut, just measure with a tape measure or other device with a millimeter scale).

  Assume that the wall thickness is 1 mm. This figure is multiplied by 2 (if the thickness is 3 mm, then it is also multiplied by 2 in any case) and subtracted from the outer diameter (18.85- (2 x 1 mm) = 16.85 mm).

  It's great if you have a caliper at home. The pipe is simply wrapped around the measuring teeth. We look at the desired value on a double scale.

Types of steel pipes according to their production method

Electrowelded (straight-seam)

For their manufacture, strips or sheet steel are used, which are bent to the desired diameter on special equipment, and then the ends are connected by welding.

The impact of electric welding guarantees minimum width seam, which makes it possible to use them for the construction of gas pipelines or water pipelines. The metal in most cases is carbon or low-alloy.

Indicators finished products regulated by the following documents: GOST 10704-91, GOST 10705-80 GOST 10706-76.

At the same time, please note that a pipe made in accordance with standard 10706-26 is distinguished by maximum strength among its own kind - after creating the first connecting seam, it is reinforced with four additional ones (2 inside and 2 outside).

The regulatory documentation indicates the diameters of products manufactured by electric welding. Their size is from 10 to 1420 mm.

Spiral-seam

The material for production is steel in rolls. Products are also characterized by the presence of a seam, but unlike the previous production method, it is wider, which means that the ability to withstand high internal pressure is lower. Therefore, they are not used for the construction of gas pipeline systems.

A specific type of pipe is regulated by GOST under the number 8696-74 .

Seamless

The production of a particular type involves the deformation of specially prepared steel blanks. The deformation process can be carried out both under the influence high temperatures, and in a cold way (GOST 8732-78, 8731-74 and GOST 8734-75, respectively).

The absence of a seam has a positive effect on the strength characteristics - the internal pressure is evenly distributed over the walls (there are no "weak" places).

As for the diameters, the standards control their manufacture with a value of up to 250 mm. When buying products with sizes exceeding those indicated, you have to rely only on the integrity of the manufacturer.

It is important to know!

If you want to buy the most durable material, buy cold-formed seamless pipes. The absence of temperature effects has a positive effect on the preservation of the original characteristics of the metal.

Also, if an important indicator is the ability to withstand internal pressure, then choose round products. Profile pipes cope better with mechanical loads (they are well made metal frames and so on.).

Here are a couple more great slides of creative advertising for a pipe manufacturer:

MAIN PARAMETERS OF INCH THREADS
(standards BSW (Ww), BSF, UNC, UNF)

The tops and bottoms of the profile of an inch thread, similarly to a metric thread, are flat cut. The pitch of an inch thread is determined by the number of threads (turns) per 1 inch, but it has a 55° point angle (Whitworth thread - British BSW (Ww) and BSF), a 60° point angle (American UNC and UNF standard ).

The outside diameter of the thread is measured in inches 1" = 25.4 mm- dash (") symbol inches. An inch thread is characterized by the number of threads per inch. According to American standards, inch threads are made with coarse (UNC) and fine (UNF) pitch.
NPSM- American standard for inch cylindrical pipe threads.
NPT- American standard for inch conical threads.

Standards:

ASME/ANSI B1.1– 2003 Unified Inch Screw Threads, UN & UNR Thread Form
ASME/ANSI B1.10M– 2004 Unified Miniature Screw Threads
ASME/ANSI B1.15– 1995 Unified Inch Screw Threads, UNJ Thread Form

AMERICAN INCH THREAD

The main parameters of the inch thread:

d(D)- the outer diameter of the thread, respectively, of the bolt and nut;
dp (Dp)- the average thread diameter of the bolt and nut, respectively;
d i (D i)- the inner diameter of the thread, respectively, of the bolt and nut;
n is the number of threads per inch.

American Coarse Pitch Thread - UNS

American Fine Pitch Thread - UNF

American Extra Fine Pitch Thread - UNEF

Thread sizes are the outside diameter of the thread expressed in fractional inch. One of the main characteristics of an inch screw thread is the number of threads per inch of thread length (n). The number of turns and the thread pitch P are related by:

American standards provide for two forms of thread:

Thread with a flat cavity, which is indicated by the letters UN;
- a thread with a radius cavity, which is indicated by the letters UNR.

The standard defines three classes of thread accuracy. These classes are designated as 1A, 2A, 3A, 1B, 2B, 3B. Accuracy classes 1A, 2A, 3A refer to external threads; accuracy classes 1B, 2B, 3B refer to internal threads. Accuracy class 1A, 1B is the coarsest and is used in cases where quick and easy assembly is required, even with partially dirty and dented threads. Accuracy class 2A, 2B is the most common and is used for threads general purpose. Accuracy class 3A, 3B imposes the most stringent requirements on threads and is used in cases where it is required to ensure a minimum clearance in a threaded connection.

Thread designation. The nominal size is written first, then the number of threads per inch of the thread, the thread group symbols, and the accuracy class symbol. The letters LH at the end of the entry indicate the left-hand thread. The nominal size is the outer diameter, defined as a fractional size or thread number, or their decimal equivalent.
For example: 1/4 - 20UNS - 2A or 0.250 - 20UNC - 2A

BRITISH STANDARD INCH THREADS
(BSW(Ww) and BSF)

Related Documents:

GOST 3469-91: Microscopes. Thread for lenses. Dimensions
GOST 4608-81: Metric thread. Interference landings
GOST 5359-77: Ocular thread for optical instruments. Profile and dimensions
GOST 6042-83: Round Edison thread. Profiles, dimensions and limit dimensions
GOST 6111-52: Conical inch thread with a profile angle of 60 degrees
GOST 6211-81: Conical pipe thread
GOST 6357-81: Cylindrical pipe thread
GOST 8762-75: Round thread with a diameter of 40 mm for gas masks and calibers for it. Main dimensions
GOST 9000-81: Metric thread for diameters less than 1 mm. Tolerances
GOST 9484-81: Trapezoidal thread. Profiles
GOST 9562-81: Trapezoidal single thread. Tolerances
GOST 9909-81: Conical thread of valves and cylinders for gases
GOST 10177-82: Thrust thread. Profile and main dimensions
GOST 11708-82: Thread. Terms and Definitions
GOST 11709-81: Metric thread for plastic parts
GOST 13535-87: Reinforced thrust thread 45 degrees
GOST 13536-68: Round thread for sanitary fittings. Profile, basic dimensions, tolerances
GOST 16093-2004: Metric thread. Tolerances. Landings with clearance
GOST 16967-81: Metric thread for instrumentation. Diameters and steps
GOST 24737-81: Trapezoidal single thread. Main dimensions
GOST 24739-81: Multi-start trapezoidal thread
GOST 25096-82: Thrust thread. Tolerances
GOST 25229-82: Metric conical thread
GOST 28487-90: Tapered tool joint thread for drill string elements. Profile. Dimensions. Tolerances

In the construction market, 2 sizes of structures are popular:

• 1\2 and 3\4 - make up a separate category. due to special thread parameters (1.814), per 1 unit. measures accounted for 14 strands;
• within 1 - 6 inches, the pitch is reduced to 2.309, forming 11 threads that do not affect the decrease or increase in the quality of the connection.

One inch is 25.4 mm long, it is used to determine the internal parameters, but when laying reinforced pipes, the diameter is 33.249 mm (including the internal section and 2 walls). In assortment steel structures there is an exception - products in ½ inch, where the outer section is 21.25 mm. This parameter used when calculating the dimensions of pipes with a cylindrical thread type. When calculating for pipes with a cross section of 5 inches, the internal dimension will be 12.7 cm, and the external - 166.245 (reduced to 1 decimal place is allowed).

The difference between measurement systems

In terms of external parameters, inch designs do not differ from metric ones, the difference lies in the type of notches. There are 2 types of threads according to the inch system - English and American. The first option corresponds to a notch angle of 55 degrees, and the metric (American) system with an angle of 60 degrees. generally accepted.

At different degrees, it is difficult to distinguish the angle by 55 - for inch and 60 - for metric designs, and the rounding of the threads is immediately visible, the occurrence of an error is impossible. A thread gauge is used to measure the thread pitch, but an ordinary ruler or other device is well used instead.

Replacing steel pipes with polymer ones

In gas and water supply network steel products are used, the diameter of which is indicated in inches (1", 2") or fractions (1/2", 3/4"). When measuring a 1" pipe cross-section, the result is 33.5 mm, which corresponds to 1" (25.4 mm). When arranging pipeline reinforcing elements, where the parameters are indicated in inches, there are no difficulties. But when installing products made of PP, copper or stainless steel instead of steel structures, it is required to take into account the difference in the name and parameters.

To create a given level of flow, the internal diameter of the pipes is taken into account. For inch ordinary pipes, it is 27.1 mm, for reinforced 25.5 mm, closest to 1 ". Pipelines are designated in conventional units of the flow area Du (DN). It determines the parameters of the pipe clearance and is indicated in digital values. sections are selected taking into account the increase in throughput characteristics by 40-60% with an increase in the index.If the external cross section and the purpose of the structures are known, using the size table, the internal cross section is determined.

In the process of connecting steel pipes with polymer structures, replacing one with another, conventional adapters are used. Dimensional mismatch results from the use of copper, aluminum or stainless steel products manufactured to metric standards. The actual metric dimensions of the pipes are taken into account - internal and external.

Steel pipes of the Russian Federation in comparison with the European standard

To compare the range of pipes according to GOST RF and European standards, the following table is used:

How to decide on the choice of diameter?

From diameter water pipes their throughput characteristics depend - the volume of water passed for 1 unit. time. It depends on the speed of the water flow. With its increase, the risk of pressure drop in the line increases. Throughput characteristics are calculated according to formulas, but when planning intra-apartment wiring, they take pipes of certain parameters.

For the plumbing system:

• 1.5 cm (1/2 inch)
• 1 cm (3/8 inch).

For the riser, structures with an internal cross section are used:

• 2.5 cm (1 inch);
• 2 cm (3/4 inch).

Given that the internal cross section of half-inch polymer pipes varies from 11 to 13 mm, and one-inch pipes from 21 to 23, an experienced plumber will be able to determine the exact parameters when replacing. With a complex type of wiring, numerous joints, turns and laying the network at a great distance, reducing the pressure, it should be possible to carry out the wiring of pipes with a large cross section. As the diameter increases, the pressure level increases.

Below is a table for determining the patency of steel pipes:

Steel pipe diameter

The cross section of the pipes corresponds to a number of indicators:

• Nominal diameter (Dn, Dy) - nominal parameters (in mm) of the internal cross-section of pipes or their rounded indicators, in inches.
• Rated value (Dn Dn,).
• external size.

  The metric calculation system allows classifying structures into small ones - from 5 ... 102 mm, medium - from 102 ... 426, large - 426 mm and more.

• Wall thickness.
• inner diameter.

The internal cross section of pipes with different threads corresponds to the following parameters:

• 1/2 inch pipeline - 1.27 cm;
• 3/4 inch - 1.9 cm;
• 7/8 inch - 2.22 cm;
• 1 inch - 2.54 cm;
• 1.5 inches - 3.81 cm;
• 2 inches - 5.08 cm.

The following indicators are used to determine the thread diameter:

• pipeline 1/2 inch - 2.04 - 2.07 cm;
• 3/4 inches - 2.59 - 2.62 cm;
• 7/8 inch - 2.99 - 3 cm;
• 1 inch - 3.27 - 3.3 cm;
• 1.5 inches - 4.58 - 4.62 cm;
• 2 inches - 5.79 - 5.83 cm.

Table of correspondence between the diameter of steel pipes and polymer structures:

Steel pipe prices:

Pipe diameter PP

PP pipes are produced with a diameter of 0.5 to 40 cm or more. The diameter is internal and external. The first indicator allows you to find out the volume of environments traversed in 1 unit. time. The external cross section is used for construction calculations, namely the choice of a niche or pit for laying a highway. External parameters allow you to choose the right fittings with the corresponding internal indicators.

• Small - 0.5; 1; 1.5; 2; 2.5; 3.2; 4; 5; 6.3 and 7.5 cm is used for heating systems, drains and water supply in private buildings. An internal cross section of 3.2 cm is most popular in multi-storey buildings.
• Medium - 8; 9; 10; eleven; 12.5; 16; 20; 25 and 31.5 cm is used for arranging plumbing and sewer systems, allowing you to change cast iron products with similar external parameters. Inner size in 8, 9 and 10 cm ideal for chemical environments.
• Large - 40 cm or more is used for arranging cold water supply and ventilation systems.

Pipes are marked in inches and mm. When choosing designs for plumbing and heating system, the wall thickness is taken into account, which affects the conditional patency of highways with the same external parameters. With an increase in its parameter, an increase in pressure in the plumbing system is allowed. Small dimensions allow to reduce the level of costs for the purchase of material and water consumption.

Cost of PP pipes:

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