Types of ball valves: by connection. Methods for connecting fittings Advantages of flange connection of pipeline fittings

Electric drives are produced with the highest torques from 0.5 to 850 kgf-m in normal and explosion-proof versions with different explosion protection categories. These and other parameters of electric drives are reflected in the drive designation, consisting of nine characters (numbers and letters). The first two characters (numbers 87) indicate an electric drive with an electric motor and gearbox. The next sign is the letter M, A, B, C, D or D, indicating the type of connection of the electric actuator to the valve. The M type connection is shown in Fig. II.2, types A and B - in Fig. II.3, types B and D in - fig. II.4, type D - in Fig. P.5. The dimensions of the connecting elements are given in table. 11.106.

11.106. Dimensions of connecting elements of unified electric drives of valves

All electric actuators are connected to the valves using four studs. The diameters of the studs and the dimensions of the supporting pads are different for different types of connections. With an increase in the torque developed when driving, they increase. In connections of types B, D and D, two keys are provided in order to relieve the studs from shearing forces created by the torque transmitted from the drive to the valve.

The next figure conventionally indicates the torque of the electric drive. A total of seven gradations are provided for the general range of torques from 0.5 to 850 kgf-m (Table 11.107). Within the specified interval, adjustment to the required torque is made by adjusting the torque limiting clutch.

11.107. Symbols for electric drive parameters

The next number conventionally indicates the rotational speed (in rpm) of the drive shaft of the electric drive, which transmits rotation to the valve running nut or spindle. There are eight rotation frequencies of the electric drive drive shaft - from 10 to 50 rpm (Table 11.107).

Then the conditionally total number of revolutions of the drive shaft, which it can make depending on the design of the box of limit and torque switches, is indicated. There are six gradations in total (Table 11.107).

This limits the first group of signs. The second group consists of two letters and a number. The first letter of the second group of designations indicates the design of the drive according to climatic conditions: U - for moderate climates; M - frost-resistant; T - tropical; P - for elevated temperature. The second letter indicates the type of connection of the control cable to the electric drive box; Ш - plug connector; C - gland entry. The last digit indicates the explosion protection version of the drive. Number 1 indicates normal version H; the remaining numbers from 2 to 5 indicate explosion protection categories: 2 - VZG category; 3 - category B4A; 4 - category V4D; 5 - category RV. Thus, the electric drive under the designation 87B571 US1 has the following data: 87 - electric drive; B - type of connection; 5 - torques from 25 to 100 kgf-m; 7 - drive shaft rotation speed 48 rpm; 1 - total number of revolutions of the drive shaft (1 - 6); U - for temperate climates; C - control cable gland entry; 1 - standard explosion protection version N.

Below are brief technical characteristics and dimensional data of electric drives of the unified series.

Electric drives of normal design with M type connection with a double-sided torque limiting clutch (Fig. A.6). Symbols 87M111 USH1 and 87M113 USH1. Designed to control pipeline fittings in structures with a maximum torque of up to 2.5 kgf-m. Torque control limits are from 0.5 to 2.5 kgf-m. The total number of revolutions of the drive shaft is 1 - 6 (87M111 USH1) and 2 - 24 (87M113 USH1). Drive shaft rotation speed 10 rpm. The drive is equipped with an AB-042-4 electric motor with a power of 0.03 kW and a rotation speed of 1500 rpm. Gear ratio from the handwheel to the drive shaft = 1. A force of up to 36 kgf can be applied on the flywheel rim. Electric drives have a built-in box! travel and torque switches. Electric drive weight 11 kg. The overall dimensions of electric drives 87M111 USH1 and 87M113 USH1 are shown in Fig. P.6.

11. 108. Symbols of electric drives

11.109. Brief technical characteristics and weight of electric drives

11.110. Symbols of electric drives

Electric drives of normal design with type A connection with a double-sided torque limiting clutch (Fig. II.7). The maximum torques created by the drives are 6 and 10*kgf-m. There are eight modifications of electric shelters (Table 11.108). Technical characteristics and weight of electric drives are given in table. 11.109. Electric motor shaft rotation speed 1500 rpm Gear ratio from the handwheel flywheel to the drive shaft i = 3. Electric drives have a built-in box of travel and torque switches. Overall dimensions of electric drives are shown in Fig. P.7.

Electric drives of normal design with connection type B with a double-sided torque limiting clutch (Fig. II.8). The maximum torque on the drive shaft is 25 kgf-m (control interval from 10 to 25 kgf-m). There are twelve modifications of electric drives (Table 11.110). Technical characteristics of electric drives are given in table. 11.111. Motor shaft rotation speed 1500 rpm. Overall dimensions of electric drives are shown in Fig. II.8. Electric drive weight 35.5 kg.

11.111. Brief technical characteristics of electric drives

Electric drives of normal design with connection type B with a double-sided torque limiting clutch (Fig. II.9). The maximum torque on the shaft is 100 kgf m (control interval from 25 to 100 kpm). There are twelve modifications of electric drives (Table 11.112). Technical characteristics and weight of electric drives are given in table. II. 113. Waxing frequency of the electric motor shaft is 1500 rpm. The overall dimensions of the electrical wires are shown in Fig. II.9.

Electric drives of normal design with connection type G with a double-sided torque limiting clutch (Fig. 11.10). The maximum torque on the shaft is 250 kgf-m (control interval from 100 to 250 kgf). There are twelve modifications of electric drives (Table 11.114). Technical characteristics and weight of electric drives are given in table. 11.115. Motor shaft rotation speed 1500 rpm. Overall dimensions of electric drives are shown in Fig. UFO.

11.112. Symbols of electric drives

11.113. Brief technical characteristics and weight of electric drives

11.114. Symbols of electric drives

11.115. Brief technical characteristics and weight of electric drives

Electric drives of normal design with connection type D with a double-sided torque limiting clutch (Fig. 11.11). The highest torque on the drive shaft is 850 kgf-m (control interval from 250 to 850 kgf-m). Drive shaft rotation speed 10 rpm. There are six modifications of electric drives (Table 11.116). The gear ratio from the flywheel to the drive shaft is i = 56. The permissible force on the rim of the handwheel flywheel is 90 kgf. Electric drives are equipped with an AOS2-42-4 electric motor with a power of 7.5 kW and a shaft speed of 1500 rpm. Electric drive weight 332 kg. Overall dimensions of electric drives are shown in Fig. 11.11.

Rice. 11.12. Electrical control circuit for electric drives of a unified series:

D - asynchronous electric motor with a squirrel-cage rotor; KVO, KVZ - track microswitches MP 1101 for opening and closing; KV1, KV2 - additional track microswitches MP 1101; VMO, VMS - torque microswitches MP 1101 for opening and closing; O, 3 - magnetic opening and closing starters; LO, LZ, LM - signal lamps “Open”, “Closed” and “Coupling”; KO, KZ, KS - control buttons “Open”, “Closed” and “Stop”; 7 - potentiometer PPZ-20, 20 kOhm; Pr - fuse; A - automatic; 1 - 4 - microswitch contacts

Explosion-proof electric drives are also available:

11.116. Symbols of electric drives

The electrical control circuit for electric drives (same for all) is shown in Fig. Item 12. In the “Open” position the LO signal lamp is on, in the “Closed” position the LM and LM lamps are on, in the “Emergency mode” position the LM lamp is on. The operation of microswitches is clear from the table. 11.117.

11.117. Operation of microswitches (Fig. 11.12)

The word “flange” came into the Russian language from the German language along with the flange itself, and was not assigned on the basis of some analogies. In German, the noun Flansch means exactly the same thing as the Russian word “flange” derived from it, ─ a flat metal plate at the end of a pipe with holes for threaded fasteners (bolts or studs with nuts). It is more common when this plate is round, but the shape of the flanges is not limited to one disk. For example, square and triangular flanges are used. But round ones are easier to make, so the use of rectangular or triangular flanges can be justified for really compelling reasons.

The material, types and design features of the flanges are determined by the nominal diameter, pressure of the working medium and a number of other factors.

For the manufacture of pipeline valve flanges, gray and ductile cast iron and different types of steel are used.

Ductile iron flanges are designed to withstand higher pressures and a wider temperature range than flanges made from gray cast iron. Cast steel flanges are even more resistant to these factors. Welded steel flanges, while easily withstanding high temperatures, are inferior to cast flanges in the maximum permissible pressure.

Design features of flanges may include the presence of projections, chamfers, spikes, annular recesses, etc.

The prevalence of flanged connections for pipeline fittings is due to their many inherent advantages. The most obvious of them is the possibility of repeated installation and dismantling. The temptation to add the adjective “easy” to the noun “installation” is somewhat diminished if we remember how many bolts will need to be unscrewed and tightened when disassembling and joining flanges of large diameters (flange connections are usually used for pipe diameters of 50 mm or more). Although in this case, the complexity of installation work will not go beyond reasonable limits.

Flange connections are durable and reliable, which allows them to be used to complete pipeline systems operating under high pressure. Subject to certain conditions, flange connections provide very good tightness. To do this, the flanges being joined must have similar connecting dimensions that do not exceed the permissible error. Another condition is mandatory periodic tightening of joints, which allows maintaining the “grip” of bolted joints at the proper level. This is especially important when they are constantly exposed to mechanical vibrations or there are significant fluctuations in ambient temperature and humidity. And the larger the diameter of the pipeline, the more relevant this is, because as it increases, the force on the flanges increases. The tightness of flange connections largely depends on the sealing ability of the gaskets installed between the flanges.

Deformations cannot be discounted. Moreover, flanges made of different materials are susceptible to them to different degrees, therefore the material from which it is made is the most important parameter of the flange. Thus, ductile steel flanges are deformed more easily than those made of cast iron, which is more brittle but holds its shape much better.

The disadvantages of flanged fittings are a continuation of its advantages. High strength results in significant overall dimensions and weight, which, in turn, mean increased metal consumption (in the manufacture of large-sized flanges, it is necessary to use a thick metal sheet or round profiles of large diameter) and labor-intensive production.

Weld fittings

Welding of reinforcement is resorted to when the reliability and tightness of other types of connections is considered unsatisfactory. Welding is especially in demand when constructing pipeline systems in which the working environment is toxic, poisonous or radioactive liquids and gases. In this case, a welded connection, which, if properly executed, provides 100 percent tightness, may be the optimal, and often the only acceptable solution. It is only important that such a section of the system does not require frequent dismantling of equipment, the implementation of which will each time lead to complete destruction of the welded joints.

Thanks to welding, which combines fragments of the pipeline system into a single whole, it is possible to ensure harmony, or, in technical terms, structural compliance between all its elements - pipes and pipeline fittings. The main thing is that, due to differences in the mechanical properties of the welded joint and other components of the pipeline system, it does not become its weak link.

The connecting ends of the reinforcement are prepared for welding by leveling and grinding the surface of the welded fragments, removing the required chamfers.

Welded joints can be made in socket and butt. In the first case, the welding seam is located on the outside of the pipe. This option is usually used for steel fittings of relatively small diameter, installed in pipelines operating at high pressure and temperature of the working environment.

In the second case, the connection can be supplemented with a backing ring, which prevents distortion of the parts being connected. It is precisely these connections, characterized by reliability and absolute tightness, that are used when installing pipeline systems of hazardous production facilities, for example, power units of nuclear power plants.

Important advantages of welded connections, especially compared to flanged ones, are minimal weight, compactness and space saving.

Coupling fittings

One of the most common in technology is the coupling connection of reinforcement.

It is used for various types of valves of small and medium diameter, operating at low and medium pressures, the body of which is made of cast iron or non-ferrous alloys. If the pressure is high, then it is preferable to use pin fittings.

In the connecting pipes of coupling fittings, the thread is on the inside. As a rule, this is a pipe thread ─ inch thread with a fine pitch. It is formed in various ways - knurling, cutting, stamping. It is important that with a fine thread pitch, the height of the teeth does not depend on the diameter of the pipeline.

On the outside, the connecting ends are designed in the form of a hexagon to make it convenient to use the key.

The word “coupling” came into Russian from German, and possibly from Dutch, where mouw means sleeve. The coupling, like the valve, is an example of how tailoring and the production of pipeline fittings each use in their special terminology words that sound the same, but carry different meanings. In engineering, a coupling is not a sleeve, but a short metal tube that provides connections to the cylindrical parts of machines.

The fine thread of the coupling connection plus the use of special viscous lubricants, flax strands or fluoroplastic sealing material (FUM tape) guarantee its high tightness. A coupling connection does not require the use of additional fasteners (for example, bolts or studs, as in a flange connection). But one cannot ignore that screwing a coupling onto a thread with a seal requires considerable effort, the greater the larger the diameter of the pipeline.

Union fittings

The German origin of the term “fitting” from the verb stutzen (to trim, cut) even reveals its sound. This is the name given to the muskets used to arm armies up until the 19th century, due to the presence of a rifled barrel. In modern technology, this noun is used to define a short piece of pipe (in other words, a sleeve) with threads on both ends, used to connect pipes and pipeline fittings to units, installations and tanks. In a fitting connection, the connecting end of the valve with external thread is pulled to the pipeline using a union nut. It is used for fittings of small and ultra-small (with a nominal diameter of up to 5.0 mm) diameters. As a rule, this is laboratory or other special fittings. For example, reducers installed on compressed gas cylinders. Using a fitting connection, various control and measuring instruments (I&M) are “implanted” into pipeline networks, evaporators, thermostats, and many types of equipment that are part of chemical production lines are installed.

Pin fittings

The term “pin joint” came into widespread use at the end of the 19th century. Its main attributes for pipeline fittings are connecting pipes with external threads and the presence of a collar. The end of the pipeline with the flange is pressed against the end of the fitting pipe using a union nut.

The pin connection is used for small-sized high-pressure fittings, in particular, instrumentation devices. It is effective when screwing fittings into the body of vessels, devices, installations or machines. Its tightness is ensured by the presence of gaskets and special lubricants.

An example of a pin connection would be the connection of a fire hose to a fire hydrant.

All threaded connections have such advantages as a minimum number of connecting elements, low metal consumption and, accordingly, low weight, and manufacturability. Effective installation of threaded connections requires matching internal and external threads and the use of soft or viscous materials for sealing. But it should be taken into account that threading reduces the thickness of the pipe wall, so this type of connection is not suitable for thin-walled pipes.

In addition to those listed, there are other ways to connect fittings. Thus, durite compounds can be used in pipeline systems. These are connections through cylindrical couplings, consisting of several layers of rubberized fabric (in simple words, fragments of hoses), pushed onto protrusions made on the pipes and fixed with metal clamps.

Another method of connecting fittings is soldering, which is used for copper pipes with a small diameter. The end of the pipeline, treated with solder, is inserted into the groove made in the pipe.

The functionality, operability and reliability of a pipeline system is determined not only by the parameters of the fittings included in its composition, but also by the quality ofdone reinforcement connection , the selection and implementation of which should always be given special attention.

Has an internal threaded connection. Thanks to this threaded connection, the coupling valve has a shorter overall length and weight.

Diagram of a coupling ball valve

The advantage of the crane is that additional fasteners are not needed for a reliable connection. It is also indispensable in those sections of the pipeline where there is not enough space to work with a wrench.

Flange ball valve

Attaches to flanges. Connection is ensured by two flanges, an O-ring, connecting bolts and nuts.

Diagram of a flanged ball valve

The valves are easy to install and maintain, they can be mounted and dismantled many times, while flanged valves are large in size and weight. They are usually used on pipelines where frequent installation and dismantling of valves is required.

Ball valve

This is a valve with an external thread, to which a nipple with a union nut is attached. The design ensures the small size and weight of the product, while this crane is easy to maintain and install.

Diagram of a ball valve

They are easy to install and maintain, they can be mounted and dismantled many times. Unlike flanged valves, it takes up less space and can be installed in hard-to-reach places.

Welded ball valve

Has welded ends. Such taps are lightweight, hermetically attached to the pipe, but are difficult to maintain: dismantling and replacing them is quite labor-intensive.

Diagram of a welded ball valve

Designed for high pressure working environment, therefore they have high tightness of the overlap and strength of the connection.

FEDERAL AGENCY FOR TECHNICAL REGULATION AND METROLOGY

NATIONAL

STANDARD

RUSSIAN

FEDERATION

Pipeline fittings ROTARY ACTION DRIVES Connecting dimensions

Industrial valves - Multi-turn valve actuator attachments

Industrial valves - Part-turn valve actuator attachments

Official publication

Standardinform

Preface

1 DEVELOPED by the Closed Joint Stock Company "Research and Production Company "Central Design Bureau of Valve Engineering" (CJSC "NPF "TsKBA") on the basis of ST TsKBA 062-2009 "Pipeline fittings. Rotary motion drives. Connecting dimensions"

2 8NESEN Technical Committee for Standardization TC 259 “Pipe fittings and bellows”

3 APPROVED AND 8PUT INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated August 20, 2013 No. 529-Art.

4 This standard takes into account the main regulatory provisions of the following international standards:

ISO 5210 “Pipeline fittings. Connecting dimensions of multi-turn actuators" (ISO 5210 Industrial valves - Multi-turn valve actuator attachments", NEQ):

ISO 5211, “Pipeline fittings. Connecting dimensions of part-turn actuators" (ISO 5211 "Industrial valves - Part-turn valve actuator attachments", NEQ)

5 INTRODUCED FOR THE FIRST TIME

The rules for applying this standard are established by GOST R 1.0 - 2012 (section 8). Information about changes to this standard is published in the annual (as of January 1 of the current year) information index “National Standards”, and the official text of changes and amendments is published in the monthly information index “National Standards”. In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the next issue of the monthly information index “National Standards”. The corresponding information, notification and texts are also posted on the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet (gost.ru).

© Standardinform. 2014

This standard cannot be fully or partially reproduced, replicated or distributed as an official publication without permission from the Federal Agency for Technical Regulation and Metrology

1 ... 1 ... 1 ..2 16

1 area of ​​use............................................... ...........................................

3 Terms and definitions................................................... ....................................

4 Types of connections................................................... ...........................................

5 Designation of connection types.................................................... ...................

Appendix A (mandatory) Connecting dimensions of multi-turn valves

drives for connection types MCH. MK. AC. AK. B. C. D. D...........................

Bibliography

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Pipeline fittings

ROTARY DRIVES

Connection dimensions

Pipeline valves. Drives of rotary action The connecting dimensions

Date of introduction -2014-02-01

1 area of ​​use

This standard applies to rotary actuators and actuators (hereinafter referred to as actuators) (multi-turn and part-turn, electric, pneumatic, hydraulic, as well as gearboxes) and establishes the types of connections of actuators to pipeline fittings, the connecting dimensions of actuators and the dimensions of counter connections of the pipeline fittings controlled by them .

2 Normative references

This standard uses normative references to the following standards:

GOST R 52720-2007 Pipeline fittings. Terms and Definitions

GOST 22042-76 Studs for parts with smooth holes. Accuracy class B. Design and dimensions

3 Terms and definitions

In this standard the following terms are used with their corresponding

definitions:

3.3 multi-turn actuator: A device that imparts a torque to the valve sufficient for at least one revolution. May have the ability to withstand axial load (1].

3.4 part-turn actuator: A device that transmits torque by rotating its output element by one revolution or less, and does not have the ability to withstand an axial load.

3.5 gearbox: A mechanism designed to reduce the torque required to control pipeline fittings)