Thermal shut-off valve: purpose, installation. Thermal shut-off safety valves Thermal shut-off valves KTZ: product price

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 is exceeded gas pipeline above 80-100°С 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 stop 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. Discover current price thermal shut-off valve is possible by contacting our managers.

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 setting. stop valve.

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 the 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 impulse sampling The safety shut-off valve must be made close to the pressure regulator impulse sampling point, i.e. at a distance of at least five diameters of the outlet gas pipeline from the pressure regulator. It is unacceptable to connect the safety shut-off valve to the lower part of the horizontal section of the gas 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 an actuating mechanism for safety automation that stops the gas supply when any of the controlled parameters deviates beyond the specified limits (including at the command of a 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 bandwidth, leading to a two-position mode of its operation at low gas flow rates and causing bursts of output 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.
A common cause of a sharp decrease in pressure for any network may be a violation of the tightness of gas pipelines and fittings, and, consequently, a gas leak.

To prevent an unacceptable increase or decrease in pressure in the 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.

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 increase 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.

Type: thermal shut-off valve.

The KTZ valve is installed on pipelines as an automatic safety device blocking the pipeline with gas in the event of a fire.

Main technical data and parameters of KTZ valve

Working pressure: 6 kg/cm 2 .

Nominal diameter: 15 - 300 mm.

Response temperature: 80-100 °C.

Valve body material: steel 20.

The working position of the CTZ on the pipeline: any.

KTZ are disposable devices and cannot be restored.

Pipe connection type:

1. threaded connection: (inner-outer) (inner-inner) version KTZ 001.

2. flange version KTZ 001-02.

KTZ damper corresponds to UHL version: category 3 according to GOST 15150-69.

Service life of short circuit protection plant established by the manufacturer: not less than 10 years.

Transportation and storage conditions: 2 (C) according to GOST 15150-69

The manufacturer guarantees that the manufactured valves comply with the requirements of TU 3742-001-89363468-2010, provided that the consumer observes the conditions of transportation, storage, installation and operation.

Warranty period of operation: 18 months from the date of sale of the valve, subject to the rules of storage, installation and operation.

Service life of KTZ established by the manufacturer: at least 10 years.

Pressure losses in KTZ threaded valves depending on gas flow

The device and principle of operation of the KTZ valve.

The KTZ thermal shut-off valve consists of a body, in the cavity of which a spring-loaded locking element is installed, held in the open state by a stop with a fusible insert. When the valve temperature reaches more than 90 °C, the fusible insert melts, the locking element is released and shuts off the gas flow. The thermal shut-off valve is a device for single actuation, multiple use (repairable).

Installation and operating instructions

During installation and operation, it is necessary to observe the "Rules fire safety PPB-01-03 and the requirements of GOST 12.2.063-81.

The position of the axis of the installed valve in space can be any.

It is not allowed to install dampers with a response temperature of +93°C in areas where the temperature environment can rise above +60 °C, and for valves with a response temperature of +79 °C, not higher than +50 °C.

Before installation, make sure that the valve is in the open position and is not damaged.

The direction of the gas flow must correspond to the arrow on the valve body. A special heat-resistant gasket should be installed on the side of the flow inlet to the valve for flanged and wafer-type KTZs, and a heat-resistant sealing winding or heat-resistant sealant for threaded KTZs.

It is forbidden to expose the valve to sharp mechanical impacts and shocks.

At the end installation work, during pressure testing of a section of the pipeline contained by the CTP, as well as when starting gas, the shut-off valves should be opened smoothly in order to avoid breaking the latch and closing the valve due to the occurrence of a large pressure drop.

During the operation of the KTZ does not require maintenance.

After actuation, the valve can be restored to its original state at the factory. It is forbidden to use the valve without a passport.

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, developed special valves 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 highways natural gas, regardless of their complexity, branching and the number of consumer devices by systems of temperature-sensitive control and cut-off of supply.
• 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 valve 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 provided extra pressure pipes by bending or twisting 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 building, it is recommended to install several shut-off valves for each branch.