Thermal shut-off valve: purpose, installation. Thermal shut-off safety valves Terms and definitions

Gasified facilities must have protection systems against possible leakage and ignition of gas. There can be many reasons for this, and one of them is a fire in the room. A fire causes an increase in temperature that can reach the flammable limit of the gas and cause it to explode. To prevent this, special valves have been developed to cut off the gas supply in the event of a fire.

Thermal shut-off valve: purpose

An automatic type of valve that shuts off the gas pipeline to all gas-powered devices during a fire is called a thermal shut-off valve. This device reduces the risk of explosions, injury and physical damage.

The installation of KTZ thermal shut-off valves is regulated by the standards set forth in the fire safety rules. They prescribe:

• Equip any types of natural gas pipelines, regardless of their complexity, branching and the number of consumer devices, with temperature-sensitive control and supply cut-off systems.
• Use as protective devices valves designed to operate when the ambient temperature reaches one hundred degrees Celsius.
• Install thermal shut-off modules at the entrance to the room.

Valves are marked in the form of KTZ with a number after it. The number indicates the diameter of the gas supply pipe on which this valve can be installed.

Operating principle

The thermal shut-off valve consists of a body with a threaded connection, a fusible insert, a spring mechanism and an element (shutter) in the form of a plate or a ball that closes the channel.

In the initial state, at normal room temperature, the shut-off element of the valve is cocked and held by a fusible link. When ignited, the overall temperature rises, reaching its mark of 85-100 degrees leads to the melting of the insert and the release of the cut-off mechanism. The latter, in turn, under the action of a spring, blocks the gas flow channel.

The thermoshut-off valve (KTZ) can work with any gases. After operation, it is replaced with a new one. It is possible to replace the fusible insert with another and further operation of the product.

Installation rules

In order for the thermal shut-off valve to work reliably, it is necessary to adhere to the rules for its installation:

• Threaded valves must be installed in lines with a pressure not exceeding 0.6 MPa. The valves do not withstand pressure up to 1.6 MPa.
• The flow capacity of the valve must not be less than the flow capacity of the gas line.
• It is necessary to install a thermal shut-off valve on the gas pipeline in the very first place, and then the rest of the fittings.
• KTZ should be installed indoors and protect fittings that are not designed for high heat.
• The valve axis can be located in any direction.
• The flow of gas, the direction of which is indicated on the body of the device, must be taken into account.
• Installing the damper in places close to heating elements, the air temperature near which may exceed 53 degrees, is excluded.
• The built-in thermal shut-off valve must be checked for leaks.
• After installing the KTZ, it should not be subjected to additional pipe pressure, bending or unscrewing the device.
• Access to the valve must be free and unobstructed.

Conclusion

When buying a thermal shut-off valve, you should make sure that the channel cut-off mechanism has not worked, which sometimes happens during transportation. With complex gas distribution inside the premises and the presence of several fuel consumers located in different parts of the building, it is recommended to install several shut-off valves for each branch.

A safety shut-off valve is a fitting that is open in service. The gas flow through it stops as soon as the pressure at the controlled point of the gas pipeline reaches the lower or upper limit of the safety shut-off valve setting.

The safety shut-off valve has the following requirements:

It must ensure hermetic closure of the gas supply to the regulator in the event of an increase or decrease in pressure behind it in excess of the established limits. The upper limit of operation of the safety shut-off valve must not exceed the maximum working pressure after the regulator by more than 25%;
calculated for the inlet working pressure in the series: 0.05; 0.3; 0.6; 1.2; 1.6 MPa with a response range when pressure increases from 0.002 to 0.75 MPa, as well as a response range when pressure decreases from 0.0003 to 0.03 MPa;
the design should exclude spontaneous opening of the shut-off body without the intervention of maintenance personnel;
the tightness of the shut-off body must comply with class "A" in accordance with GOST 9544-93;
operation accuracy should be ± 5% of the set values ​​of controlled pressure for the safety shut-off valve installed in the hydraulic fracturing, and ± 10% for the safety shut-off valve in the hydraulic fracturing and combined regulators;
response inertia should be no more than 40–60 s;
the free passage of the shut-off body must be at least 80% of the nominal passage of the nozzles safety shut-off valve;
the shut-off body should not be at the same time the executive body of the gas pressure regulator.
Controlled pressure pulse sampling The safety shut-off valve must be made close to the pressure regulator's pulse sampling point, i.e. at a distance of at least five diameters of the outlet gas pipeline from the pressure regulator. Do not connect the safety shut-off valve to the lower part of the horizontal section of the pipeline to prevent the ingress of condensate.

The safety shut-off valve installed in the hydraulic fracturing and on-site hydraulic fracturing is often used as a safety automation actuator that stops the gas supply when any of the controlled parameters deviates beyond the specified limits (including at the command of the gas contamination detector). In this case, the safety shut-off valve is usually equipped with an electromagnetic device. The safety shut-off valve also includes thermal shut-off valves that shut off pipelines in the event of a temperature increase of up to 80–90 ° C.

Increasing or decreasing the gas pressure after the pressure regulator in excess of the specified limits can lead to an emergency. With an excessive increase in gas pressure, flame separation from the burners and the appearance of an explosive mixture in the working volume of gas-using equipment, leakage, gas leakage in the joints of gas pipelines and fittings, failure of instrumentation, etc. are possible. A significant decrease in gas pressure can lead to slippage of the flame into the burner or extinction of the flame, which, if the gas supply is not turned off, will cause the formation of an explosive gas-air mixture in the furnaces and gas ducts of the units and in the premises of gasified buildings.

The reasons for the unacceptable increase or decrease in gas pressure after the pressure regulator for dead-end networks are:

Malfunction of the pressure regulator (jamming of the plunger, the formation of hydrate plugs in the seat and body, valve leakage, etc.);
incorrect selection of the pressure regulator according to its throughput, leading to a two-position mode of its operation at low gas flow rates and causing outbursts of outlet pressure and self-oscillations.
For ring and branched networks, the reasons for an unacceptable pressure change after the pressure regulator can be:

Malfunction of one or more pressure regulators supplying these networks;
incorrect hydraulic calculation of the network, due to which abrupt changes in gas consumption by large consumers lead to surges in outlet pressure.
common cause sharp decline pressure for any networks, there may be a violation of the tightness of gas pipelines and fittings, and consequently, a gas leak.

To prevent unacceptable increase or decrease in pressure in hydraulic fracturing (GRPSh), high-speed safety shut-off valves and safety relief valves are installed.

The safety shut-off valve is designed to automatically stop the gas supply to consumers in the event of an increase or decrease in pressure above the specified limits; they are installed after the pressure regulators. safety shut-off valve is activated when " emergency situations”, so their spontaneous inclusion is unacceptable. Before manually switching on the safety shut-off valve, it is necessary to detect and eliminate malfunctions, and also make sure that the shut-off devices in front of all gas-using devices and units are closed. If, under the conditions of production, a break in the gas supply is unacceptable, then instead of a safety shut-off valve, an alarm system should be provided to alert the operating personnel.

The safety relief valve is designed to discharge into the atmosphere a certain excess volume of gas from the gas pipeline after the pressure regulator in order to prevent pressure from rising above the set value; they are installed after the pressure regulator on the outlet pipeline.

If there is a flow meter (gas meter), a safety relief valve must be installed after the meter. For GRPSh it is allowed to take out the safety relief valve outside the cabinet. After the controlled pressure drops to the set value, the safety relief valve must close hermetically.

Thermal shut-off valve KTZ - control valves, made in the form of a valve, used to completely shut off the flow of the working medium.

All gasified facilities have protection systems that will work in the event of a possible leak or gas fire. There can be many reasons for such actions. One of the main ones is a fire in the room. A fire can lead to an increase in temperature, which reaches a limit and leads to an explosion. To avoid this, there are special cut-offs in the form of valves that prevent fire or gas leakage.

Purpose of the KTZ thermal shut-off valve

Thermal shut-off valve can be used to shut off a gas pipeline leading to all gas appliances. Due to its use, possible explosions, as well as injuries or physical damage are significantly reduced.

The installation of KTZ valves is regulated by the regulations that are part of the rules on fire safety. This includes the following prescriptions:

• Equipment of complex natural gas pipelines using a large number of installations. All this allows you to cut off possible unforeseen situations that will lead to unpleasant consequences.
• The use of valves as thermal protection devices. They signal an accident in advance, taking into account the ambient temperature.
• Installation of thermal protection modules at the entrance to the room.

Thermal shut-off valves have a specific marking. The numbers in the marking code indicate the diameter of the gas pipe and the need to install a valve.

Thermal shut-off valve - principle of operation

Thermal shut-off valve KTZ includes a body with a threaded connection and a spring mechanism insert. In the normal state, the locking element of such a device is held by a fusible link. In the event of a fire, the temperature will rise, causing the insert to melt and release the shut-off mechanism. With the help of a spring, it blocks the gas flow channel.

All types of KTZ thermal shut-off valves work with any kind of gas.

Features of the installation of thermal shut-off valves

To ensure reliable operation of the thermal safety valve, it is worth adhering to some installation rules:

• valves on a threaded connection must be installed in lines with low pressure. On a flange connection, they are able to withstand pressure up to 1.6 MPa.
• each valve has a good flow capacity of the gas line.
• the installation of the valve on the gas pipeline is carried out at the very beginning, and then the installation of the main fittings is carried out.
• a shut-off valve must be provided indoors to protect the fittings from overheating.
• the valve axis can be located in any direction.
• gas flow should be taken into account when installing the device near the housing.

GOST R 52316-2005

Group G88

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Fire fighting equipment

THERMAL SHUT-OFF VALVES

General technical requirements. Test Methods

fire equipment. Thermal equipment trips.
general technical requirements. Test methods

OKS 13.220.10
OKSTU 4854

Introduction date 2006-01-01

Foreword

Tasks, basic principles and rules for carrying out work on state standardization in Russian Federation established GOST R 1.0-92 "State standardization system of the Russian Federation. Basic provisions" and GOST R 1.2-92 "State standardization system of the Russian Federation. Development procedure state standards"
________________
* GOST R 1.0-2004 is valid on the territory of the Russian Federation.
** On the territory of the Russian Federation, GOST R 1.2-2004 applies. - Note "CODE".

About the standard

1 DEVELOPED AND INTRODUCED by the Technical Committee for Standardization TC 274 "Fire Safety"

2 APPROVED AND PUT INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated February 28, 2005 N 33-st

3 INTRODUCED FOR THE FIRST TIME

Information about changes to this standard is published in the "National Standards" index, and the text of these changes - in the "National Standards" information indexes. In case of revision or cancellation of this standard, the relevant information will be published in the information index "National Standards"

1 area of ​​use

1 area of ​​use

This standard applies to newly developed and manufactured thermal shut-off valves for automatically shutting off gas pipelines when they are heated during a fire (hereinafter - KTZ).

The standard establishes general technical requirements and test methods for short circuit protection devices designed to automatically shut off household and industrial gas pipelines located in the area of ​​internal fires.

2 Normative references

This standard uses normative references to the following standards:

GOST 2.601-95 Unified system for design documentation. operational documents.

GOST 12.2.003-91 Occupational safety standards system. Production equipment. General safety requirements

GOST 12.2.007.0-75 Occupational safety standards system. Electrical products. General safety requirements

GOST 12.2.063-81 Occupational safety standards system. Fittings industrial pipeline. General safety requirements

GOST 356-80 Fittings and details of pipelines. Pressure conditional, trial and working. ranks

GOST 4666-75 Pipe fittings. Marking and distinctive coloration

GOST 6357-81 Basic norms of interchangeability. Cylindrical pipe thread

GOST 6527-68 Coupling ends with cylindrical pipe thread. Dimensions

GOST 9697-87 Shut-off valves. Main settings

GOST 12815-80 Flanges of fittings, fittings and pipelines from 0.1 to 20.0 MPa (from 1 to 200 kgf/cm). Types. Connecting dimensions and dimensions of sealing surfaces

GOST 12816-80 Flanges of fittings, fittings and pipelines from 0.1 to 20.0 MPa (from 1 to 200 kgf/cm). General technical requirements

GOST 13955-74 Threaded fittings for pipeline connections along the outer cone. Design and dimensions

GOST 14192-96 Marking of goods

GOST 14254-96 (IEC 529-89) Degrees of protection provided by enclosures (IP Code)

GOST 15150-69 Machinery, instruments and other technical products. Versions for different climatic regions. Categories, conditions of operation, storage and transportation in terms of the impact of environmental climatic factors

GOST 16039-70 Threaded fittings for pipeline connections along the inner cone. Design and dimensions

GOST 16504-81 State product testing system. Testing and quality control of products. Basic terms and definitions

GOST 17433-80 Industrial purity. Compressed air. Pollution classes

GOST 21130-75 Electrical products. Grounding clamps and grounding signs. Design and dimensions

GOST 21752-76 Man-machine system. Flywheels and steering wheels. General ergonomic requirements

GOST 21753-76 Man-machine system. Control levers. General ergonomic requirements

GOST 24193-80 Collar clamps. Design

GOST 24194-80 Female collars. Design

GOST 24705-2004 Basic norms of interchangeability. The thread is metric. Main dimensions

GOST 26349-84 Pipeline connections and fittings. Pressures are nominal (conditional). ranks

GOST 26350-84 Pipeline connections and fittings. Connection threads. ranks

GOST 28338-89 (ISO 6708-80) Piping connections and fittings. Conditional passages (nominal dimensions). ranks

GOST R 12.4.026-2001 Occupational safety standards system. Signal colors, safety signs and signal markings. Purpose and rules of application. General technical requirements and characteristics. Test Methods

GOST R 50460-92 Mark of conformity for mandatory certification. Shape, dimensions and technical requirements

GOST R 51330.1-99 (IEC 60079-1-98) Explosion-proof electrical equipment. Part 1: Flameproof type of protection

Note - When using this standard, it is advisable to check the validity of the reference standards according to the "National Standards" index, compiled as of January 1 of the current year, and according to the corresponding information indexes published in the current year. If the reference document is replaced (modified), then when using this standard, you should be guided by the replaced (modified) standard. If the referenced document is canceled without replacement, the provision in which the link to it is given applies to the extent that this link is not affected.

3 Terms and definitions

In this standard, the following terms are used with their respective definitions:

3.1 thermal shut-off valve(KTZ): Pipeline shut-off valves that automatically shut off the gas flow in the event of a fire in the area of ​​its installation.

3.2 thermal shut-off valve of conventional design: KTZ without additional built-in locking device.

3.3 combined thermal shut-off valve (combined thermal shut-off valve): KTZ with an additional built-in locking device that has manual control or is triggered when an external control action is applied (electric, hydraulic, pneumatic, pyrotechnic).

3.4 thermal lock: A device consisting of a mechanism that holds the locking element of the CTZ in open position, and a temperature-sensitive element, which is triggered when it reaches a temperature equal to the nominal temperature of the operation of the temperature-sensitive element, after which the shut-off body of the KTZ must be in the closed position.

3.5 temperature sensitive element: A device that collapses or changes its original shape at a given temperature.

3.6 temperature sensitive element: A temperature sensitive element that allows replacement when triggered, while maintaining the subsequent performance of the short circuit.

3.7 nominal response temperature of a thermal shut-off valve (thermal lock, temperature sensing element): technical documentation.

3.8 conditional response time of the thermal shut-off valve (thermal lock) (hereinafter referred to as the response time): Time from the moment of placing the short circuit (thermal lock, temperature-sensitive element) with thermally insulated input and output into the thermostat at a temperature of 650 ° C until the activation of the short-circuit protection (thermal lock, temperature-sensitive element).

3.9 structural volume of KTZ: Volume numerically equal to the volume of liquid displaced by the given CVT.

3.10 incentive drive: A combination of thermal locks and/or a tension cable and a pipeline filled with water, an aqueous solution and/or compressed air, designed to provide automatic and remote actuation of a short circuit.

4 Classification

4.1 KTZ are divided into the following types:

4.1.1 according to the design for:

- normal execution (KTZ),

- combined execution (KTZk);

4.1.2 according to the nominal diameter of the passage - according to GOST 28338;

4.1.3 according to nominal pressure - according to GOST 356 and GOST 26349;

4.1.4 according to the nominal operating temperature of the short circuit protection (thermal lock): 57, 68, 72, 74, 79 and 93 ° С;

4.1.5 by type of additional drive of combined short circuits for:

- hydraulic (G),

- pneumatic (P),

- electrical (E),

- mechanical (M),

- manual (P);

4.1.6 according to the working position on the pipeline relative to the horizontal plane on:

- vertical (B),

- horizontal (G),

- universal (U).

Note - Universal short circuits - in the working position on the pipeline - can occupy at least two spatial positions;

4.1.7 according to the type of connection with the gas pipeline and / or fittings on:

- flange threaded (FMn),

- coupling threaded (MvMn),

- flanged (F),

- threaded (Mv, Mn, Gv, Gn),

- clamp (X),

- coupling (M),

- welded (C).

Note - With a two-digit designation F, Mv, Mn, Gn, X or C, the first capital letter means the inlet connection, the second - the outlet connection, for example, FMn - flange threaded, MvMn - threaded coupling, etc .;

4.1.8 according to the degree of protection of the shell - according to GOST 14254;

4.1.9 according to the type of explosion protection - according to GOST R 51330.1.

4.2 The KTZ designation should have the following structure:

Notes

1 For a threaded connection, after the letters "Mv" or "Mn" put down the diameter and pitch of the thread in millimeters, and after the letters "Gv" or "Gn" - the diameter of the thread in inches (lowercase letters "v" and "n" mean, respectively, internal or external thread).

2 In the absence of a protective or decorative coating of the hull, the designation of the hull coating may not be affixed.

3 In the designation of the working position on the gas pipeline of the universal KTZ, the letter "U" may not be indicated.

4 In the combined KTZ, after the letter indicating the type of additional drive, indicate:

- for an electric drive and its various combinations - the value of the rated supply voltage in volts, for example (E24), (E220);

- for pneumatic and hydraulic - the minimum operating pressure in megapascals, for example (D 0.05).

4.3 Examples of symbols:

- thermal shut-off valve of conventional design with a nominal diameter of 25 mm, a nominal pressure of 0.6 MPa, a threaded type of connection to the gas pipeline (inlet - G1 cylindrical pipe thread, outlet - G1 cylindrical pipe thread), with a universal working position on the gas pipeline, internal fusible temperature-sensitive element with a response temperature of 72 °C, climatic version U, placement categories 4:

KTZ 25-0.6 (Gv 1 - Gn 1) U-72.U4

Thermal shut-off valve of combined design with nominal diameter of passage 80 mm, nominal pressure 1 MPa, flange type connections with a gas pipeline, with a vertical working position on the gas pipeline, with an external rupture temperature sensitive element, a response temperature of 68 °C, an additional drive supply voltage of 220 V, an explosion protection level (explosion-proof type "Explosion-proof enclosure") "2ExdllCT3X", climatic version UHL, placement category 3 :

KTZk 80-1 (F)V-68-E220 - 2ExdllCT3X.UHL3

5 Technical requirements

5.1 KTZ should be manufactured in accordance with the requirements of this standard and regulatory documents (RD) for this product, approved in the prescribed manner.

5.2 Characteristics

5.2.1 Purpose indicators

5.2.1.1 Nominal pressure PN - according to GOST 356 and GOST 26349.

5.2.1.2 The nominal diameter of the passage DN KTZ must comply with GOST 28338.

5.2.1.3 The nominal response temperature of the thermal lock of the short circuit locking device, the maximum deviation of the nominal response temperature, the color of the marking strip on the housing of the short circuit breaker, the color of the liquid in the thermoflask or the shackles of the fusible external thermal lock must correspond to the values ​​\u200b\u200bgiven in Table 1.


Table 1

5.2.1.4 Conditional response time - according to the technical documentation (TD) for a particular type of product.

5.2.2 Requirements for resistance to external influences

5.2.2.1 The maximum allowable operating temperature of the CT should not be less than that specified in Table 2.


table 2

In degrees Celsius

5.2.2.2 Permissible air leakage through the short circuit breaker with the shut-off device actuated should be no more than 0.5 l/min at a temperature of 650 °C (reduced to a temperature of 20 °C) and pressure PN specified in the TD for a particular type of product.

5.2.2.3 In terms of resistance to climatic influences, KTZ must comply with the requirements of GOST 15150.

5.2.2.4 Conditions for transportation and storage of KTZ - according to GOST 15150.

5.2.2.5 CTs in packaging for transportation shall withstand without damage the effects of transport shaking with an acceleration of 30 m/s at a frequency of 80 to 120 beats per minute.

5.2.3 Design requirements

5.2.3.1 The pressure loss of the CTS should not exceed the values ​​given in Table 3.


Table 3

5.2.3.2 The housing, joints and seals of the CTZ must be airtight.

5.2.3.3 KTZ should provide strength at test pressure in accordance with GOST 356.

5.2.3.4 Mounting dimensions of KTZ - according to GOST 6527, GOST 9697, GOST 12815, GOST 12816, GOST 13955, GOST 16039, GOST 24193, GOST 24194 and GOST 26350.

5.2.3.5 dimensions KTZ - according to TD for a product of a specific type. Overall, connecting dimensions, type of thread, body color, external thermal lock should allow its sealing.

5.2.3.6 Metric threads used in KTZ must comply with GOST 24705, cylindrical pipe threads - GOST 6357.

5.2.3.7 The body of the KTZ must be painted red in accordance with GOST R 12.4.026. Other coloring is allowed at the request of the customer.

5.2.3.8 The design of a replaceable external thermal lock shall allow its sealing in the working position.

5.2.3.9 Manual activation force of combined short circuit protection devices - in accordance with GOST 21752 and.

5.2.3.10 In the combined short circuit protection system, it shall be possible to visually control the state of the locking device: in the open or closed position, the additional manual drive devices must be provided with pointers (arrows) and / or inscriptions: "Open", "Closed".

5.2.3.11 When used in a combined short circuit electric drive, the supply voltage must be 220 or 380 V AC or 24 V direct current; voltage fluctuations from plus 10% to minus 15%.

5.2.3.12 The electrical insulation resistance of the current-carrying circuits of the combined short circuit with an electric drive at a supply voltage of 220 V must be at least 20 MΩ.

5.2.3.13 A combined short circuit with an electric drive and a supply voltage of 220 V or more must have a terminal and a ground sign. The terminal, sign and grounding point must comply with GOST 12.2.007.0 and GOST 21130.

5.2.3.14 Requirements for the additional drive of the combined CTZ - according to the TD for a product of a specific type.

5.2.3.15 The mass of the KTZ - according to the TD for a product of a specific type.

5.2.3.16 The assigned service life of the short circuit is at least 10 years.

5.3 Completeness

5.3.1 The scope of supply together with the KTZ should include:

- technical description, instructions for installation and operation;

- passport (or passport combined with technical description and operating instructions) according to GOST 2.601;

- a set of special tools and accessories required for installation and maintenance (at the request of the consumer);

- a set of replaceable temperature-sensitive elements (at the request of the consumer).

5.3.2 The operational documentation shall contain information on 4.2, 5.2.1, 5.2.2.1-5.2.2.4, 5.2.3.1, 5.2.3.4, 5.2.3.5, 5.2.3.7, 5.2.3.8, 5.2.3.11-5.2 .3.13, 5.2.3.15, 5.2.3.16, 5.3, 5.4, 5.5.4, 6.2 and Appendix A.

5.4 Marking

5.4.1 The KTZ or a plate attached to the KTZ body must be marked in accordance with GOST 4666 containing the following data:



- symbol: nominal diameter, nominal pressure, type of connection to the gas pipeline, nominal response temperature;

- an arrow indicating the direction of flow (or the words: "Entrance", "Exit");

- a sign of the working position in space (if it is limited);

- minimum operating stimulating hydraulic or pneumatic pressure (for combined short circuit protection);

- supply voltage and explosion protection level (for combined short circuit protection);

- a terminal and a ground sign (for a combined short circuit if a voltage of more than 24 V is applied to it);

- mark of conformity according to GOST R 50460;

- year of issue.

5.4.2 Marking of KTZ with a nominal diameter of DN 50 or less may contain limited information:

- trademark or name or mark of the manufacturer;

- symbol: nominal pressure, nominal response temperature (when using a sprinkler sprinkler as a thermal lock, the nominal response temperature is not marked on the body);

- an arrow indicating the direction of flow;

- a terminal and a ground sign (if 220 or 380 V is supplied to the short circuit).

5.4.3 For the combined short circuit, an additional marking of the conditional hydraulic or pneumatic pressure of the additional incentive drive should be applied. The marking is affixed in an accessible place on the additional incentive drive or on the body of the short circuit breaker at the point of attachment of the additional incentive drive or on a plate attached to the casing of the short circuit near the additional incentive drive.

5.4.4 The marking is affixed in any accessible place on the body or flange of the KTZ or on a plate attached to the body of the KTZ.

5.4.5 Marking should be made in accordance with GOST 4666 in any way that ensures its clarity and safety throughout the entire service life of the short circuit.

5.4.6 An example of marking a thermal shut-off valve with a nominal diameter of DN 80 mm, for a nominal pressure of PN 0.6 MPa, a connection to a gas pipeline - an external cylindrical thread G2, with a fusible temperature-sensitive element П, a nominal response temperature of 79 °С:

KTZ 80-0.6 Gn 2 P79

The year of issue is entered in two digits, for example "02".

5.5 Packaging

5.5.1 The method of packaging, preparation for packaging, shipping containers and materials used in packaging, the procedure for placing CTs in shipping containers must comply with the TD for a particular type of product.

5.5.2 The packaging must exclude the free movement of the CTZ both in general and in individual containers.

5.5.3 Shipping containers must be marked in accordance with GOST 14192. Mandatory application of the sign "Temperature Limit" indicating the specific storage temperature.

5.5.4 Each container must contain a passport for KTZ (or a passport combined with a technical description and operating instructions) and a packing list containing:

- name and designation of KTZ;

- the number of KTZ in the container;

- batch number;

- date of packaging;

- stamp and signature of the person responsible for packaging;

- OTK stamp

6 Safety requirements

6.1 KTZ safety requirements - according to GOST 12.2.003, GOST 12.2.007.0, GOST 12.2.063 and the Industrial Safety Rules in gas industry, and KTZk with an electric drive - also according to the Rules for the installation of electrical installations.

6.2 Safety requirements when testing for air leakage through the short circuit with the shut-off device activated during the temperature effect on the short circuit - in accordance with Appendix A.

7 Acceptance rules

7.1 KTZ should be subjected to tests: acceptance, periodic, type according to GOST 16504 and reliability according to RD 50-690.

7.2 The nomenclature of the parameters of the short circuit, which is checked during the acceptance tests, is given in table 4. The entire batch of the short circuit is subjected to acceptance tests. The sequence of tests is not regulated.


Table 4

7.3 The nomenclature of parameters, which is checked during periodic testing, is given in Table 4. The sequence of carrying out tests of short circuit protection - according to the numbering of items in Table 4 (see Figure 1); the sequence of tests 16-18 is not regulated. Periodic tests are carried out at least once a year from among the CTs that have passed acceptance tests 1-7 of Table 4. While maintaining the same CT designs, tests to determine pressure losses are allowed to be carried out at least once every five years.

Legend:

- test number (according to table 4);

- the number of short circuits subjected to the test according to 7.5;

- tests carried out only for combined short circuits

Figure 1 - Algorithm for periodic tests of short circuit test

7.4 Type tests of KTZ are carried out with a change in technology, design, replacement of materials and other changes in the full scope of periodic tests. The test program is planned depending on the nature of the changes.

7.5 Sampling for periodic and type tests is carried out in accordance with GOST 18321; the sample size for CT with DN up to 100 mm (inclusive) - at least 6 pcs., for CT with DN over 100 mm - at least 3 pcs.

7.6 When determining the parameters, use the equipment of the appropriate accuracy class:

- manometric instruments with an accuracy class of at least 0.6;

- flow meters or gas flow meters with an error of no more than 5%;

- stopwatches and chronometers with a scale division value of not more than 0.2 s when measuring time up to 60 s and not more than 1 s when measuring time from 60 s or more;

- thermoelectric devices or thermometers with a division value of not more than 0.5 °C when measuring temperatures up to 200 °C and with a division value of not more than 2 °C when measuring temperatures of 200 °C or more;

- calipers with a division value of at least 0.1 mm;

- scales with an error of no more than 5%;

- megaohmmeters, voltmeters, ammeters and wattmeters with a measurement error of not more than 1.5%.

7.7 The tolerance for the initial values ​​of physical and electrical quantities, unless otherwise specified, is taken equal to no more than 5%.

7.8 All tests should be carried out under normal climatic conditions according to GOST 15150.

8 Test methods

8.1 Strength tests of the housings of the short-circuit protection system (5.2.3.3) are carried out before the assembly of internal parts that are not connected with the outer surface of the housing. The strength of the KTZ body is checked by test hydraulic pressure according to GOST 356 for at least 5 minutes. The rate of pressure increase from zero to the test hydraulic pressure is uniform, the duration is at least 15 s.

Residual deformations, signs of body destruction, water leakage through the metal, as well as through gaskets and other types of joints and seals are not allowed.

8.2 All KTZ are preliminarily inspected to identify obvious defects (5.2.3.6), the completeness of the delivery (5.3.1) and the marking (5.4) are controlled.

8.3 The presence of a seal on a replaceable external thermal lock (5.2.3.8) is checked by visual inspection.

8.4 The presence of a terminal and a ground sign on a combined short circuit with an electric drive (5.2.3.13) is checked by visual inspection.

8.5 The possibility of visual control of the state of the additional shut-off element of the combined CT "Open" - "Closed" and the inscriptions "Open" - "Closed" (5.2.3.10) is checked visually.

The manual controls in the open position should be located along the longitudinal axis of the CTZ body, in the closed position - across the longitudinal axis.

8.6 Compliance with the parameters of the short circuit protection presented in the TD for this product with the requirements of this standard (5.3.2) is checked by comparing the parameters of the short circuit protection presented in the TD with the qualitative and quantitative indicators given in 4.2, 5.2.1, 5.2.2.1-5.2.2.4 5.2.3.1, 5.2.3.4, 5.2.3.5, 5.2.3.7, 5.2.3.8, 5.2.3.11-5.2.3.13, 5.2.3.15, 5.2.3.16, 5.3, 5.4, 5.5.4, 6.2 and Annex A: code name (type) KTZ, type of connection with the gas pipeline, working position on the gas pipeline, type of additional drive combined KTZ, maximum operating pressure PN, nominal diameter of the passage DN, type of thermal lock, nominal response temperature, maximum deviation of the nominal response temperature, color of the marking strip on the case of the short circuit, color of the liquid in the thermoflask or the shackles of the fusible external thermal lock, conditional response time, maximum permissible operating temperature, permissible air leakage, climatic modification, conditions of transportation and storage, pressure losses of the short circuit, overall and connecting dimensions, type of thread, color of the body , the possibility of sealing an external thermal lock, the supply voltage, the electrical resistance of the insulation of the current-carrying circuits of the combined short circuit, the presence of a terminal and a grounding sign.

8.7 Overall and connecting dimensions (5.2.3.4, 5.2.3.5) are checked with an appropriate measuring tool.

8.8 The mass (5.2.3.15) is checked by weighing.

8.9 The test of the CTS in the packaging for transportation on the effect of transport shaking (5.2.2.4) is carried out on a shaker. KTZ in a package (container) is mounted on the platform of the test bench without additional external shock absorption. The tests are carried out with an acceleration of (30 ± 3) m/s at a frequency of 80 to 120 beats per minute for at least 2 hours. After the test, an external examination of the CTZ is carried out.

Signs of destruction of the container and mechanical damage to the CT located in it, as well as residual deformation of the CT, are not allowed.

8.10 Tests for resistance to climatic influences (5.2.2.3) are carried out in accordance with GOST 15150 (heat resistance - not lower than 50 °C). KTZ is kept at appropriate temperatures for at least 3 hours. Between tests for cold resistance and heat resistance and after tests, KTZ is kept in normal climatic conditions for at least 3 hours.

Signs of mechanical damage are not allowed.

8.11 The tightness test of the body, joints and seals of the KTZ (5.2.3.2) is carried out in the open position of the shut-off devices with pneumatic conditional pressure PN according to GOST 356 for at least 5 minutes. The rate of pressure increase from zero to maximum - no more than 0.1 MPa/s.

Air leakage through the housing, mounting, gasket and other types of connections and seals is not allowed.

8.12 The test of combined short circuit protection devices for actuation of an additional shut-off device from the supply voltage (5.2.3.11) is carried out by changing the supply voltage in the range from plus 10% to minus 15% of the nominal value. At extreme values ​​of the supply voltage, the operation of the short circuit is checked with the operating hydraulic parameters given in 5.2.1.1. The number of tests at each voltage value is at least three.

The criterion for a positive assessment is the operation of the device under test.

8.13 The electrical insulation resistance of the current-carrying circuits of combined short circuits (5.2.3.12) is determined by a megohmmeter with a rated voltage of 500 V. The resistance is measured between each terminal of the electrical conductor and the outer sheath of the conductor, as well as between each terminal of the electrical conductor and the body of this electromechanical equipment or ground terminal.

The electrical resistance of the insulation of current-carrying circuits must be at least 20 MΩ.

8.14 The test of the combined short circuits for the force of manually actuating the additional shut-off device (5.2.3.9) is carried out in the absence of pressure and pressure at the inlet PN on all controls intended for this purpose. The dynamometer is mounted on the handle or flywheel of the control in the center of the place where the force of the hand is applied. The axis of force application must be perpendicular to the handle. The handle or flywheel is turned from one extreme position to another and back. The number of test cycles at each pressure value is at least three.

The result is taken as the maximum value of the actuation force of the control (the force of starting the control is not taken into account), which should be no more than specified in GOST 21752 or GOST 21753.

8.15 Tests, which should be carried out according to the range of technical parameters of the additional drive of combined CTs not specified in this standard (5.2.3.14), are carried out according to the methods set forth in the TD for a specific type of product.

8.16 The response temperature (5.1.2.3) is checked by heating the CTZ immersed in a liquid bath from a temperature of (20 ± 5) °С to a temperature (20 ± 2) °С lower than the nominal response temperature at a rate of not more than 20 °С / min. KTZ at this temperature is maintained for at least 10 minutes, and then the temperature is increased at a constant rate of not more than 1 ° C / min until the thermal lock is destroyed.

The temperature is measured at the KTZ housing near the thermal lock. The ratio of the dimensions of the bath filled with liquid ("length-width-height") - 1±20%:1±20%:1±20% (or "diameter-height" - 1±20%:1±20%). As a working liquid, a liquid with a boiling point higher than the nominal temperature of the operation of the thermal lock of the KTZ (for example, water, glycerin, mineral or synthetic oils) should be used. The volume of fluid must be at least five times the volume of fluid displaced by the CTZ.

The response temperature must not exceed that specified in table 1.

Note - If the thermal lock is outside and it is allowed to dismantle it from the CTZ housing, then only the thermal lock or (sprinkler) can be tested.

8.17 The response time of the STC (5.2.1.4) is checked by placing the STC with a temperature of (20 ± 2) °C in a thermostat with a temperature of (650 ± 15) °C. The capacity of the thermostat must be at least six times the design volume of the CT. The inlet and outlet of the CTZ must be hermetically insulated with metal foil with a thickness of more than 0.2 mm or flanges. Ventilation of air inside the thermostat must be excluded. The temperature is measured on the outer side of the CTZ housing near the thermal lock.

The response time of the short circuit from the moment it is placed in the thermostat should not exceed the values ​​specified in the TD for a particular type of product.

8.18 Test for air leakage through the short circuit with the actuated locking device (5.2.2.2).

8.18.1 The test is carried out on bench equipment, including:

- a test electric heating chamber (hereinafter referred to as the chamber) or a test furnace with a fuel supply and combustion system (hereinafter referred to as the furnace);

- a device for installing CTZ in a chamber or furnace;

- air supply system through KTZ;

- temperature control system inside the chamber or furnace;

- a system for measuring the temperature in the chamber or furnace, supply pressure and air flow (or registration of limiting air leaks).

8.18.2 KTZ is mounted in the geometric center of the chamber or furnace. The inlet and outlet pipelines of the air supply system through the KTZ must be located outside the chamber or furnace. The inlet and outlet pipelines must be of such length that at the inlet and outlet of the outlet pipelines the ambient temperature during the test does not exceed 30 °C.

8.18.3 If a flow meter (or gas flow meter) is used to measure leaks, then it is installed at the inlet of the inlet pipeline, if an indicator device is used, then it is installed at the outlet of the outlet pipeline.

8.18.4 The temperature in the chamber or furnace is brought to (650 ± 15) °С for at least 10 minutes, while the uniformity of heating of the internal space of the chamber or furnace is not regulated.

8.18.5 The temperature is maintained within (650 ± 15) °C for at least 35 minutes, if the short circuit has already worked before. If until the temperature reaches (650 ± 15) °C, the CTC has not yet worked, then this temperature is maintained until the CTC is activated for at least 35 minutes after the CTC is triggered.

8.18.6 At the moment of reaching the temperature (650 ± 15) °C, if the CT has already been activated, air is supplied to the CT at a pressure equal to the conditional pressure PN, and the air flow rate is measured for at least 3 minutes or leaks through the CT are recorded. If before reaching the temperature (650 ± 15) °C, the short circuit has not yet worked, then the measurement of air flow or the registration of leakage through the short circuit start from the moment the short circuit is activated. After 30 minutes, the same tests are repeated.

The air flow rate or leakage through the CTZ must not exceed 0.5 l / min (reduced to a temperature of 20 ° C).

8.18.7 The temperature in the chamber or furnace is measured when testing the short circuit with DN up to 100 mm near the thermal lock, and when testing the short circuit with DN 100 mm or more, near the thermal lock and at the ends of the short circuit. The distance from the soldered end of the thermocouple to the outer surface of the CTZ housing, measured along any coordinate, must be no more than 10 mm.

8.18.8 The temperature in the chamber or furnace is measured by thermocouples with electrodes with a diameter of 0.75-3.20 mm. The soldered end of the thermocouple must be free. The protective casing of the thermocouple shall be removed (cut off and removed) at a length of (25 ± 10) mm from its soldered end.

8.18.9 The flame of the burners should not touch the tested CT and thermocouples.

8.18.10 The linear dimensions of the internal cavity of the chamber or furnace must exceed linear dimensions KTZ not less than 1.5 times.

8.18.11 The air used for testing must comply with GOST 17433.

8.18.12 Leakage of air through the CTZ with the shut-off device activated should not exceed 0.5 l/min (reduced to a temperature of 20 °C).

8.19 The pressure loss of the CTC (5.2.3.1) is determined with the CTC open according to the scheme shown in Figure 2, on samples that have passed the tests according to 8.16. The length of the pipeline before and after the short circuit must be 10 DN diameters. The set value of the air flow (normalized to a temperature of 20 °C) is set according to table 3 (depending on the nominal diameter DN).

1 - flow regulator; 2 - thermometer; 3 - flow meter or gas flow meter; 4 - pressure gauge;
5 - differential pressure gauge; 6 - tested KTZ

Figure 2 - Scheme for measuring the pressure loss of the CTZ

The reduced air flow rate is determined by the formula

where - air consumption, reduced to a temperature of 20 ° C, m / h;

- measured air flow at ambient temperature, m/h;

- barometric pressure, MPa;

- pressure in the pipeline in front of the CTP, MPa;

- ambient temperature, °С.

The pressure loss must not exceed the value given in table 3 for the nominal diameter DN corresponding to the tested short circuit

8.20 The assigned service life (5.2.3.16) is controlled by processing statistical data.

9 Transport and storage

9.1 Transportation of KTZ in packaging should be carried out in covered vehicles of any type in accordance with the rules applicable to this type of transport

9.2 During loading and unloading, shocks and other careless mechanical impacts on the container should be avoided.

9.3 Conditions for transportation and storage of KTZ - according to GOST 15150.

Annex A (mandatory). Safety requirements for testing for air leakage through the short circuit

Annex A
(mandatory)

A.1 Among the personnel maintaining the test equipment, there should be a person responsible for safety.

A.2 When performing tests, a hand-held or portable powder fire extinguisher is required.

A.3 When carrying out tests, it is necessary to determine an area around the chamber or furnace with a width of at least 1.5 m, into which outsiders are prohibited from entering during the tests.

A.4 B working area The room must be naturally or mechanically ventilated to provide the persons conducting the tests with sufficient visibility and safe working conditions without breathing apparatus and thermal protective clothing during the entire test.

A.5 The fuel supply system shall be provided with means of light and/or sound signaling.

Bibliography

PB 12-368-00 Industrial safety in the gas industry

PUE-98 Rules for the installation of electrical installations

RD 50-690-89 Guidelines. Reliability in technology. Methods for assessing reliability indicators based on experimental data



The text of the document is verified by:
official publication
Moscow: IPK Standards Publishing House, 2005

Thermal shut-off valve KTZ

Valve thermostop (KTZ), price for a wide range of different modifications of which is presented on this page of our catalog, is a reliable and efficient mechanism for automatically cutting off the gas supply in case of heating. When the temperature of the gas pipeline exceeds 80-100°С, the triggered gas valve thermostop KTZ shuts off the gas supply to consumer devices, thereby reducing the likelihood of an explosion and facilitating the task of fighting the spread of fire.

Valve KTZ, belonging to the category of shutoff valves, is installed on gas pipelines with a working pressure in the range of 0.6-1.6 MPa. For gas pipelines with a lower pressure limit, thermal shut-off valves with a threaded connection (coupling KTZ) are used, closer to the upper - KTZ with a flange connection.

Gas valve KTZ: design and principle of operation

The design of the KTZ damper is a profiled steel body with a check valve and a spring with a locking element. In the compressed position, the spring is held by a fusible insert-stopper, which provides throughput. When the temperature in the room or on the gas pipeline reaches 90 ° C, the low-melting stopper melts out, releasing the compressed spring. A cone-shaped shut-off element is lowered onto the valve seat, thus sealing it and cutting off the gas supply through the pipeline.

Thermal shut-off valves KTZ: product price

The price of a KTZ valve for buyers directly depends on the diameter of the product and the type of its connection. You can find out the current price of a thermal shut-off valve by contacting our managers.