Pipes

Device, manufacturers and specifications according to GOST ball valves. We disassemble ball valves: technical characteristics

Ball valves: technical specifications

If you decide to replace heating radiators, install plumbing or simply water or gas meters, then you will simply need to buy a ball valve or valve.

But first you need to decide on the technical characteristics of the product, the methods of destination, the material of manufacture, the main types and differences of ball valves for plumbing, heating, dimensions.

Why is this type of valve called ball valve?

If you take the faucet in your hands and turn the handle of the faucet, then inside it you will see a steel valve made in the form of a ball with a hole. When the tap is opened, the valve rotates, allowing free passage for the flow of water or gas. In the closed state, the “ball” is turned perpendicular to the flow, which completely blocks its movement.

ball valve

Types of ball valves or valves, their differences, dimensions and specifications

Ball valves differ in the diameter of the internal passage, the type of thread (internal or external), working pressure, the material from which they are made, the manufacturer of the product and the environment of use.

The diameter or size of the ball valve used in the installation of a water and gas pipeline is different. Most often, ball valves with an internal passage diameter of 1/2 inch or 3/4 inch are used, which corresponds to 15 mm, 20 mm or 25 mm. Less commonly used pipes and taps with a diameter equal to 1 inch, 1 1/4 inches, 1 1/2 or 2 inches.

For example, in an apartment or a private house for cold and hot water supply, it will be enough to install a half-inch 1/2 ball valve, because. The diameter of the pipe always corresponds to the diameter of the faucet. For a heating system, if there is a circulation pump in it, a 3/4 inch diameter pipe and, accordingly, ball valves of the same diameter are sufficient.

If the heating system will have a natural circulation of the coolant, then it is reasonable to use pipes and taps of a larger diameter. This indicator should be at least 40-50 mm.

The diameter of a ball valve is usually indicated on the valve itself. The symbol indicating these specifications is DN. For example, the designation DN15 shows us that this ball valve has a nominal diameter of the internal passage equal to 15 mm or 1/2 inch.

Ball valves are distinguished by the type of thread. It is either internal or external. In plumbing slang, an internal thread is called a nut, and an external thread is called a fitting. For example, a ball valve having an internal thread at both ends is called a “nut-nut” ball valve. If on the one hand it is internal, and on the other it is external, then the “nut-fitting”, etc.

The next indicator is the working pressure, i.e., the pressure inside the system, to the limit of which the ball valve can be used. It is measured in atmospheres, and on the product itself it is designated under the PN symbol.

For example, the designation PN40 indicates that the valve can be used in systems with a maximum working pressure of up to 40 atmospheres. In practice, ball valves with an index of at least PN16 can even be used in central heating systems, for example, to connect heating radiators, gas or.

Ball valves Valtec and Bugatti

Ball valve material

It can be silumin, brass or nickel-plated brass. In no case do not buy faucets made of silumin. It is a rather brittle alloy. A crane made of this material may fall apart even before it is used during installation.

You can distinguish a silumin faucet from a brass faucet by taking both products in your hands and comparing their weight. A faucet made of brass will be noticeably heavier.

Scope of ball valves

Typically, this type of faucet is used to shut off the flow of water or gas. How to distinguish a ball valve for gas and water by appearance? Everything is simple here - a faucet with a yellow lever or a “butterfly” is designed for a gas pipeline, faucets of any other colors are for cold or hot water supply, or heating.

Ball valve manufacturers

There are many different manufacturers on the market today. We recommend buying quality ball valves from well-known, trusted brands such as Bugatti or Valtec.

If the price of the products of these brands seems high to you, then you can purchase valves of domestic Russian manufacturers, for example, ball coupling valves 11b27p1 (GOST) of the Bologovsky Valve Plant have proven themselves well since Soviet times, have good technical characteristics, in addition, the price of their production is low.

But beware of fakes, buy goods in company stores.

Ball valve (KSh)- general industrial pipeline valves in the design of which a ball valve made of high-quality steel is used. Modern technologies for the production of sealing materials have given a sharp impetus to the improvement of valve designs, this also made it possible to use ball valves on high-pressure pipelines up to 16 MPa (160 kg/cm). Ball valves of large diameters successfully compete with gate valves and butterfly valves, and have found application in the food, agro-industrial, gas-industrial and oil industries. It so happened that this type of valves is considered one of the most demanded by installers of pipeline valves, since it has many advantages.

Small construction dimensions - the compactness of the ball valve, which simplifies installation.
The relatively light weight of the valves reduces the load on the pipeline.
Crane shutter control speed, almost in one motion.
The choice of execution option practically for any service conditions from steel to corrosion-proof KSh.
Reliable, virtually maintenance free.

The increased hydraulic resistance of the valve shutter is a little embarrassing. Steel gate valves win in this regard, but you must admit - convenient operation, compactness, ease of operation, aesthetic appearance, all these factors make ball valves more and more popular with consumers.

Designations of ball valves.

The diameter of ball valves is Du or Dn, this is the standard designation of the conditional passage, generally accepted for shutoff valves. For example, the diameter can reach 1200 millimeters, abbreviated as KSh Du1200. Different countries apply different DN standards. Standard diameters of the most popular ball valves in Russia in millimeters: 6, 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, 250, 300, 400 ... and up to 1200 The most used on pipelines KSh Du from 15 to 50 mm.
The nominal pressure of the passage media for the valve is standardly denoted by Ru or Pn, for example, Ru160 kg / cm or Pn16 MPa.
The type of valve may differ in connection to the pipeline and control of the gate; KSh manufacturers usually designate short designations with an additional letter, for example, KShF - a flanged ball valve. Well, the full designation looks something like this: KSHF Du100 Ru16.

Ball valves catalog

Catalog of ball valves - steel, cold-resistant, stainless steel valves Ru up to 160kg / cm, by connection, which can be ordered from our company.

The presented types of cranes are available in the warehouse of our company at manufacturers' prices with certificates and product passports.

Steel ball valves

For uninterrupted flow control on pipelines for different regions of our country, steel cranes are manufactured in various climatic versions for installation outdoors, under sheds and indoors. The main versions are U, HL, UHL, the bulk is made by manufacturers from carbon steel St20 according to U1, this is with regard to body parts. Cold-resistant cranes are also made - from steel 09G2S that does not change its properties up to -60 degrees Celsius. Stainless faucets are made of high quality 12X1810T stainless steel, and less often, on special order, they are made of acid-resistant steel.
Our company is a manufacturer and representative of the plant manufacturer of steel ksh RosService. All crane bodies are produced in a repairable and non-separable version.
RosService manufactures steel, two or three-piece, demountable repairable ball valves for pipelines with media pressure up to 16 MPa, DN from 15 to 200 mm. Read more: cranes RosService
The company "RosService" produces all-welded steel ball valves DN from 15 to 300 mm, PN up to 4.0 MPa, the valve body is made by welding - non-separable valves. Read more: RosService cranes - marking, general description, materials of the main parts.

Steel valves compare favorably in their price with analogues made of brass, bronze and other expensive alloys, which has made them popular today for complex installation on newly designed pipelines. In addition, choosing steel cranes, you save on your budget. Of course, there is an unfavorable moment - corrosion, but if a steel crane is mounted on a new pipeline and is selected according to the material according to the materials of the pipeline, then in fact the crane will serve you until the pipeline is dismantled and replaced. The presented steel ball valves comply with Russian GOSTs for connecting parts.

Table Du to pipe diameter (all-welded steel cranes RosServis)
DN, (mm)	Nozzle diameter / pipe wall thickness (mm)	GOST
15	21,3 / 2,8	3262
20	26,8 / 2,8	3262
25	33,5 / 3,2	3262
32	38 / 4	10705
40	48 / 3,5	10705
50	57 / 3,5	10705
65	76 /4	10705
80	89 / 4	10705
100	108 / 5	10705
125	133 / 5	10705/8731
150	159 / 6	10705/8731
200	219 / 6	10705/8731
250	273 / 8	10705/8731
300	325 / 8	10705/8731

If an acceptable cost of KSh is important to you, then the price of steel ball valves is the best option.

Technical characteristics of ball valves

The characteristics of valves depend on the materials used for the manufacture of ball valve parts, compliance with production technologies and the use of modern equipment in the production. As a result, the performance of materials of execution is higher, more opportunities for operation in the environment and a variety of compositions of throughput media. Briefly about the main characteristics of KSh for operation in the environment in different climatic conditions, designations: U - temperate climate, HL - temperate and cold, UHL - moderate, cold and acid-resistant. Also, the durability of operation depends on the quality and characteristics of the sealing materials of the ball valve and the valve stem.

,Technical differences of ball valves:

According to the materials of steel from which the body and moving parts of the crane are made - brass, steel, stainless, cold-resistant. The main element of the faucet is the ball valve in most types of stainless steel faucets.
According to maintainability - collapsible or non-collapsible (all-welded).
Along the passage - incomplete bore (reduced) and full bore.
For operation in the environment - climatic version U, HL, UHL, T.
By interaction with working media - for water and steam, for gas mixtures, acid resistance.

Ball valve control:

Manual control - handle or flywheel control element of the crane Du from 15mm.
Gear control - in the control of the shutter, a manual gearbox is used for ball valves DN from 50 mm.
KSH with electric drive - for large diameter pipelines, the electromechanical drive of the ball valve Du from 50 to 300 mm, allows you to automate flow control on the pipeline.
KSh with pneumatic drive - a drive for controlling the shutter on compressed air.

For your convenience, we suggest using the questionnaire on the site for the characteristics of ball valves - a form for selecting and ordering a ball valve

Ball valve design

Ball valves, regardless of the type of body and connection to the pipeline, have one thing in common in their design and name - this is a ball-shaped valve in a seat with sealing rings.

The design consists of four main parts.
The fixed part of the ball valve - the body (collapsible or all-welded)
The movable part, the valve gate is a ball with a through hole and a control rod.
The sealing elements of the ball valve and stem are rings and gaskets made of fluoroplast or other sealing material.
Control mechanism - handle or flywheel, gearbox, pneumatic drive or electric drive

After deciding on editing in heating or water supply systems, connecting water or heat metering devices, it is impossible to do without the use of shut-off valves. As it is desirable to use ball or plug valves. Before choosing the type of valves, it is necessary to understand what requirements it must meet. That is, it will be necessary to determine such parameters as the size of ball valves, the material and type of valve connection.

Specifications

The dimensions of the ball valve consist of thread parameters, dimensions.

One of the key characteristics of a ball valve can be called the internal (through) diameter. Other parameters include operating pressure and temperature. Of course, these parameters are determined by the material from which the cranes are made. An important role is also played by which company produced these products.

As an example, you can study the most commonly used ball valves in everyday life. Namely, when arranging engineering parts in an apartment building or a private house. Practice shows that when arranging such systems, cranes with different geometric parameters are used.

In particular, when arranging engineering systems, ball valves with passage diameters of ½ inch are used. In addition to those indicated, taps with a diameter of 1.1 ¼ 1 ½ inches are used. For example, when creating engineering networks in a country house, it is enough to use fittings with a diameter of half an inch. For the heating system, the best option would be to use fittings of three quarters of an inch. If the system is built on the basis of the natural movement of the coolant, then it makes sense to increase the diameter of the pipes and valves used to two inches.

But, of course, when choosing pipes and valves, it is necessary to be guided by the results of the calculations, which should be part of the project. Most manufacturers put markings on the surface of the faucet body, in which the installer will always see what are the dimensions of the faucets required for network installation.

The marking, as a rule, looks like this DN (nominal diameter) 15, it means that the tap has an internal (through) diameter of 15 mm, or about one second of an inch. The second digit under the designation Pn indicates the working pressure for which this shutoff valve is designed.

Documentation regarding ball valve dimensions

GOST 21345-2005 defines the ratio of the nominal diameters of ball valves and the pressure at which the operation of this type of product is permissible. So, for example, valves with DN20 can be installed in a network with a nominal pressure of the working medium of 17 MPa. It should be noted that there is a division into through passage and partially through passage cranes.

Historically, all sizes of diameters, internal and external, the nominal parameters of the thread are measured in inches. That is, in the system of measures that is adopted in some countries. To convert inches to familiar millimeters, you can use the following ratio - one inch is equal to 25.4 millimeters. But you need to understand that this is a very conditional ratio and when placing an order, the dimensions for ball valves are in inches and not in millimeters.

In the same document there is a reference to GOST 28338-89, which defines the dimensions of the diameters that are used in the design and manufacture of shut-off and other valves. In fact, these two and several more regulatory documents are the main ones for designers of heat and water supply networks for multi-apartment and private houses.

By the way, the calculation of the nominal diameter of the pipeline is determined at the design stage of the network, based on the heat load, the required parameters of temperature, pressure and the flow rate of the working medium. The calculated diameter of the pipeline is the reference point from which the brand of valves is selected.

The dimensional characteristics of a ball valve include the type of thread and its location. Both external and internal threads are used in taps. Valves with a thread applied to the outer surface are called a nut-nut, if the thread is applied to the inner surface, then such products are called a fitting - fitting.

Construction length and height

Another dimension that is directly related to the valves is the construction length. The definition of this term is as follows: this dimension shows the length of the pipeline section that will be replaced by shutoff valves. That is, this is the distance from one end of the crane to the other. Construction height is the distance from the lowest point of the crane to the highest. In other words, these are the overall dimensions.

These dimensions must be taken into account by the designer when designing the pipeline system. In addition, he must install a ball valve with dimensions that provide free access to it for maintenance and repair. In addition, it is necessary to provide access to fasteners for assembly and dismantling.

The size of the construction length is determined by GOST 3326-86. So, for example, a crane, DN 20, designed to work in a pipeline system with a pressure of Pn 4MPa, has a construction length of 150 millimeters.

By the way, the construction length is measured only in millimeters, in contrast to the diameters of the through holes and thread ratings.

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A plumbing product called a ball valve is used everywhere. In fact, this is a kind of control and shut-off valves with a ball-shaped shutter. Through a rounded through hole in the ball mechanism, the liquid passes. These products were invented more than a hundred years ago, but they gained particular popularity after the invention of fluoroplast and synthetic rubber, which ensured high tightness of the circulating medium. Our article will consider the technical characteristics of ball valves in accordance with GOST 21345-2005, their varieties, marking and other features.

Today, these products are used everywhere. They are indispensable when connecting and installing water pipes. Such taps are necessarily used when connecting various plumbing equipment (boilers, flowing gas water heaters, double-circuit boilers, etc.). They are used when installing heating radiators and heating communications themselves, when connecting water and gas meters and other metering equipment.

There are several varieties of such products, each of which has a narrower scope of use. It is important to choose the right element correctly, so we will consider in detail all the varieties and their characteristics.

Types of ball valves

Depending on the ratio of the diameter of the hole in the movable gate and the diameter of the pipe on which the element is installed, the following types of ball valves are distinguished:

Full bore products have the same diameter of the clearance in the gate as the diameter of the pipeline. They are highly reliable, because they practically exclude water pressure losses when the valve is open. Their level of hydrolosses is much lower than that of other types of valves. These devices are often used as the main locking device on the linear sections of powerful pipelines.
Standard bore or reduced members have a smaller hole diameter in the ball than the pipe lumen. The crane is selected so that the difference is one standard size. Such shut-off valves are used in main networks, for which partial pressure loss is not as critical as for powerful systems.

Depending on the connection method, the following varieties are distinguished:

Flanged mounted where it is forbidden to use welding. They are suitable for places where the possibility of partial assembly and disassembly is provided.
Valves with a welded joint are mounted to obtain a strong connection and ensure complete tightness of the installation site. They are used in critical or hard-to-reach areas of trunk systems.
Coupling fittings have an internal cylindrical or conical thread. It is used in the public utilities sector.
Combined elements do not have a limited scope of use. They are suitable for installation on any sections of pipelines for various purposes.

Special purpose valves are divided into three-way valves, products with flow control and fittings equipped with a body heating system.

The device of a ball valve for water provides for the following components:

frame;
ball plug or valve;
saddle;
for manual control there is a handle;
a special spindle that transmits force from the control handle to the bolt.

Materials for the manufacture of ball valves

There are brass and steel ball valves on sale. Brass products are installed on pipes of small diameter. If a leak appears, it is enough to tighten the nut to press the Teflon gland. Working resource - 20 thousand openings and closings.

Performance characteristics and advantages of brass devices:

reliability and durability;
the crane does not require maintenance and lubrication;
high tightness ensures no leakage;
can be mounted in any position;
handle safety;
maximum operating temperature up to +150 degrees;
working pressure - not higher than 1.6 MPa.

Steel fittings do not have bolted connections, therefore they are completely protected from leaks. Technical characteristics and advantages of steel products:

fluid flow is quickly blocked;
simple operation and installation;
no need to carry out maintenance and replace parts;
withstand high temperatures of the working fluid;
economy.

Specifications and GOST requirements

To select the right product, you need to know the frequency of use and its purpose. So, valves with a diameter of 1-1.5 inches are suitable for infrequent use and are not designed for constant high loads. Otherwise, it will fail.

For domestic purposes, elements with a diameter of 0.5-0.75 inches are suitable. 0.5 inch taps are used for installation on water supply pipes, and 0.75 inch products are used for heating systems with a circulation pump.

Large diameter models are suitable for production purposes or special applications. For domestic needs, fittings with a size of 0.5-1.5 inches are quite enough.

Marking and its decoding

Deciphering the marking of ball valves will help you choose the right product. The following markings for ball valves are used on the steam valves:

DN is a measure of the nominal diameter. According to this indicator, the standard size of the product is selected. This indicator is indicated for all metal plumbing elements that are installed on pipelines.
The working pressure is indicated by the letters WSP, MOP, PN or WOG. The designation PN is the nominal pressure of the working fluid with a temperature of 20 degrees, at which long-term operation of the product is possible. On imported products, the designation WOG or WSP is found. The first abbreviation indicates that the part can be installed in pipelines with different working media (gas, water, oil). In this case, the maximum working pressure of water vapor is usually indicated in degrees. The second indicator indicates the maximum steam pressure at the highest temperature of the transported medium. MOP is an analogue of PN, which is indicated in bars. This designation is used on gas fittings.
СW617N is the marking of the material from which the valves are made. In this case, this is the designation of brass according to the European standardization system.
Numbers such as 05/11 indicate the release date of the product. The first number indicates the month, the second - the year of issue. This designation is important for quality control of manufactured parts.
Arrows are applied to the products, which indicate the direction of the flow of the working medium. Arrows can be several or one.
The minimum and maximum operating temperatures must be indicated.

How to choose and what to look for when buying?

When choosing a suitable shut-off valve, it is recommended to pay attention to the following system parameters:

First, determine the section of pipes in the line on which you plan to install the crane.
Consider possible water hammers that can damage the shut-off valves.
Choose a product that is suitable for the specific fluid that the ball will come into contact with.
To ensure long-term performance, consider the case material and workmanship. The most short-lived silumin devices.

When buying, pay attention to the weight of the product and the gloss of the case. Metal elements are much heavier than plastic parts and they will last much longer. The luster of the body indicates a high quality product, because it is only present when chrome or nickel plating is applied to the brass body.

Overview of domestic and foreign manufacturers

Among the best manufacturers of ball valves are the following Russian and foreign companies:

ValTec is the market leader in ball valves. This brand has been producing reliable and high-quality plumbing equipment for a long time.
In second place is Bugatti products. It is also characterized by high quality, but the brand has not been on the sanitary equipment market for so long, like ValTec.
Among domestic manufacturers it is worth mentioning products of the reinforcement plant Bologovsky. The valves of this manufacturer are distinguished by an acceptable price and excellent quality.

Installing a ball valve in a water supply system

First of all, you need to decide on the installation site of the crane. If there is not much free space around the pipe, then it is important to choose the right length of the part handle so that it is convenient to rotate it. When located on a vertical pipeline, this parameter does not matter. If installation is carried out on a horizontal section of the pipe, then the handle should be located only on top. The maximum deviation is no more than 45 degrees.

After that, select a crane with suitable parameters. For domestic use, they usually buy coupling ball devices with a threaded connection. Flanged valves are needed for pipes with a diameter of 40 mm or more.

Advice! Be sure to pay attention to the diameter of the pipe where the crane will be installed. Also evaluate the types of threaded connections at the ends of pipe sections at the installation site. All these parameters are taken into account when choosing a suitable crane.

Specify the direction of fluid flow in the pipeline. Many locking devices are installed regardless of the direction of movement of the transported medium, but in any case, this parameter should be taken into account if there is an arrow on the tap.

Before installing the device, the threaded connection must be sealed with linen tow or FUM tape. After sealing, the valve is not screwed up to the stop, but so much that it is convenient to use the handle. After installation, check for leaks.

What is DN, Du and PN? Plumbers and engineers need to know these parameters!

DN - The standard designating the conditional internal diameter.

PN - Standard designating nominal pressure.

What is Du?

Doo- formed from two words: Diameter and Conditional. DN = DN. Do is the same as DN. It's just that DN is more of an international standard. Du - Russian-language representation of DN. Now it is categorically necessary to abandon such a name Du.

What is DN?

DN- Standardized diameter representation. GOST 28338-89 and GOST R 52720

Nominal diameter DN(Nominal diameter; Nominal bore; Nominal size; Nominal diameter; Nominal bore): Parameter used for piping systems as a characteristic of the connected parts of the valve.

Note - The nominal diameter is approximately equal to the internal diameter of the connected pipeline, expressed in millimeters and corresponding to the nearest value from a series of numbers taken in the prescribed manner.

What is DN usually measured in?

Under the terms of the standard, it seems that it does not have a strict binding to a unit of measure (it is written in the documents). But it refers to the size of the diameter. And diameter is measured by length. And because the unit of length can be different. For example, inch, foot, meter, etc. For Russian documents, we simply measure in mm by default. Although the documents say that it is still measured in mm. GOST 28338-89. But it does not have a unit of measurement:

How does it not have, if it has? Can you write in the comments how to understand this phrase?

It seems to have reached ... DN (serial number of diameter expressed in millimeters). That is, it does not have a unit of measurement, but, as it were, contains constant values (digital discrete values of the type: 15,20,25,32...). But it cannot be designated, for example, as DN 24. Because the number 24 is not in GOST 28338-89. There are strict values in order like: 15,20,25,32 ... And only they need to be chosen for designation.

DN is measured by the nominal diameter in mm (millimeter = 0.001 m). And if you see DN15 in Russian documents, then this will indicate an inner diameter of about 15 mm.

Conditional pass- indicates that this is the inner diameter of the pipe, expressed in millimeters - conditionally. The term "Conventional" means that the diameter value is not accurate. Conventionally, we accept that it is approximately equal to some values of the standard.

Under the conditional passage (nominal size) is understood the parameter used for pipeline systems as a characteristic of the connected parts, for example, pipeline connections, fittings and fittings. The nominal diameter (nominal size) is approximately equal to the inner diameter of the pipeline to be connected, expressed in millimeters.

According to the standard from: GOST 28338-89 it is customary to choose those numbers that have been agreed upon. And you should not invent your own numbers with commas. For example, DN 14.9 would be a designation error.

Nominal diameter approximately equal to the internal diameter of the connected pipeline, expressed in millimeters and corresponding to the nearest value from a series of numbers taken in the prescribed manner.

Here are the numbers:

For example, if the real inner diameter is 13 mm, then we write as: DN 12. If the inner diameter is 14 mm. then we take the value DN 15. That is, we select the number closest in value from the list of the standard: GOST 28338-89.

If both the diameter and the wall thickness of the pipe should be indicated in the projects, then it should be indicated as follows: f20x2.2 where the outer diameter is 20 mm. And the inner diameter is equal to the difference in wall thickness. In this case, the inner diameter is 15.6 mm. GOST 21.206–2012

Alas, we have to obey someone else's standards

Any imported materials from abroad were most often developed using a different length dimension: Inch

Therefore, most often the sizes are focused on the inch. Usually, a quotation mark is written for the place of the word inch.

1 inch = 25.4 mm. Which is the same 1” = 25.4mm.

Dimension table. Usually, a quotation mark is written for the place of the word inch.

1/2" = 25.4 / 2 = 12.7. But in reality, this 1/2" dimension is equal to a 15 mm passage. More precisely, maybe 14.9mm. for steel pipe. In general, the dimensions may differ by a few mm. Therefore, in such cases, for accurate calculations, you need to find out the inner diameter of a particular model separately.

For example, size 3/4” = 25.4 x 3/4 = 19 mm. But we write in the documents “conditionally” DN20 - approximately the inner diameter is 20mm.

Here are the actual sizes that most often correspond in the Russian translation.

The table shows the inside diameter in mm.

Nominal pressure PN: More details in GOST 26349 and GOST R 52720.

Has a unit of measurement: kgf/cm2. The designation kgf means kg x s (kilogram times s). c=1. c characterizes, as it were, the coefficient of force. That is, by multiplying a kilogram (mass) by a force, we convert mass into force. This is such an amendment for meticulous physicists. If you designate kg / cm2, in principle, you will also not be mistaken if you believe that we perceive mass as a force. Also, such a unit as kg / cm2 is erroneous in that pressure is formed from two units (force and area). Mass is another parameter. Because the mass only on the surface of the earth creates the force that presses on the earth (gravitational force). The value of c=1 on the surface of the earth. And if you fly away to another planet, then the gravitational force will be different, and the mass will create a different force. And on another planet, the coefficient c=1 will be equal to another value. For example, c=0.5 will create half the pressure.

What is PN for?

The PN value is needed in order to indicate to the device the pressure limit that must not be exceeded for the normal operation of the device for which this value is set. That is, when designing, the designer must know in advance what maximum pressure the device is designed for.

For example, if the device was given a value of PN15, this means that the device is designed for operation with a pressure not exceeding 15 kgf / cm2. Which is approximately equal to 15 bar.

1 kgf/cm2 = 0.98 bar. Roughly speaking, the value of PN is approximately equal to the Bar or the atmosphere.

For example, if the device was given a value of PN10, then it is designed for a pressure not exceeding 10 bar.

Definition of PN according to the standard

The highest excess working pressure at a working medium temperature of 293 K (20 °C), at which a given service life (resource) of valve body parts having certain dimensions, justified by strength calculation with selected materials and their strength characteristics at a temperature of 293 K (20 °C).

Russian norms: GOST 26349-84, GOST 356-80, GOST R 54432-2011

European Norms: DIN EN 1092-1-2008

American norms: ANSI/ASME B16.5-2009, ANSI/ASME B16.47-2006

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mixing unit
What is a mixing unit?
Types of mixing units for heating
Characteristics and parameters of systems
Local hydraulic resistance. What is KMS?
Capacity Kvs. What it is?
Boiling water under pressure - what will happen?
What is hysteresis in temperatures and pressures?
What is infiltration?
What is DN, Du and PN? Plumbers and engineers need to know these parameters!
Hydraulic meanings, concepts and calculation of heating circuits