Burst safety valve. Explosion valve on the boiler flue

Description:
Safety blasting valve "ARMAK" blasting proportional, spring, with an auxiliary bell, angular, flanged (Si 2501) are devices protecting against pressure growth. Burst valve used for water and other neutral liquids, as well as for air, water vapor and other chemically neutral gases and vapors. Operating temperature: from -10°С to +200°С

Burst valves with a limitation of the structural stroke of the plate to 0.12 of the seat diameter “do”, used for water and other neutral liquids. If condensation occurs at the lowest point of the blowing unit, dehydration must be anticipated. Dehydration in the valve body is only carried out upon customer request. In the case of liquids, the blowing installation should be carried out with a ramp.

Application:
The use of blast type valves 6304C.11A is recommended when the following are required: quiet operation of the valve, increased tightness of closure, protection of the sealing surface of the disc from stone deposition (if the agent is industrial and drinking water) and from minor mechanical pollution. It is strictly forbidden to install a blast valve at the inlet of a water heater without a safety-bleed valve.

Drawing:

Bursting valves are produced in the following versions:
P – standard;
G – gas-tight;

By special order, we produce the ARMAK blasting valve with an inductive proximity sensor that signals the moment of operation

Dimensions and dimensions:

DN value

passage nest

nest section

inlet flange

outlet flange

building length

building height

d1 x d2

D.P.

mm2

DN value	passage nest	nest section	opening pressure		mass ca.
d1 x d2	d0	A	P0min	P0 max	mass ca.
mm	mm	mm2	bar		kg

Non-standard versions:

Connection other than standard - if the valve body allows.
Version with an inductive proximity sensor - signaling the moment of opening of the safety valve.

Picking:
Flanges.
Connecting elements: screws, nuts, linings.
Sealing gaskets (gaskets).

Standard documentation:
Certificate of quality control.
Confirmation of compliance.
Technical and operational documentation.

Safety valve ARMAK (spring) passport

Any boiler equipment installed in a private home or business is a source of danger. The water jacket of the boiler is the same vessel under pressure, and therefore it is considered explosive. To minimize the danger, modern heat generators, as well as their wiring diagrams, provide many protective devices and systems. One of the simplest and at the same time common devices is a safety valve in a heating system. This will be discussed in this material.

Where is the safety valve installed?

To answer this question, you must first understand what it serves. The purpose of installing this simple device is to protect heating systems and prevent high blood pressure coolant in them. This can occur as a result of overheating of water in the boiler, especially for units that burn solid fuel. When the coolant in the boiler tank boils and steam formation begins, this is followed by a pressure surge in the system. The consequences may be:

leaks and ruptures of heating pipelines, most often at connections;
destruction polymer pipes and fittings;
explosion of the boiler tank, danger of electrical short circuit in the boiler room.

One small valve of a simple design can protect you from all these troubles. Based on the fact that pressure increases to a critical limit in the boiler, the safety valve must be installed as close to it as possible, on the supply pipeline. Some manufacturers of boiler equipment complete their products with a so-called safety group, which includes a relief valve, a pressure gauge and an automatic air vent. The group is mounted directly into the water jacket of the unit.

It should be noted that safety valves for heating are not always used in circuits. For example, when the heat source in the house is a gas or electric boiler, then a reset device is not required. The reason is the presence of automatic safety in these types of heat generators and the absence of any inertia. That is, when the set coolant temperature is reached, the gas burner or electrical element turn off and heating stops almost immediately.

Another thing is a solid fuel boiler or stove with a water circuit; here the installation of a safety valve is mandatory. When the firewood in the firebox has flared up and the water in the network has reached the required temperature, you need to reduce its heating. The access of air to the combustion chamber is closed and the flame dies out, but the red-hot firebox continues to rise in temperature by inertia. If the process proceeds near the limit values (temperature 90-95 ºС), then vaporization at such moments is inevitable.

As mentioned above, boiling is followed by an increase in pressure, which can be prevented by the safety valve of the heating system. It will automatically open the way out for the formed steam and release it, thereby reducing the pressure to normal. Then the device will close on its own and will be in standby mode again.

Design and principle of operation of the valve

The design of the valve is extremely simple. The body is made of high-quality plumbing brass using hot stamping technology from two cast parts in a semi-solid state. General device safety valve is shown in the figure:

The main working element of the valve is the spring. Its elasticity determines the force of pressure that should act on the membrane that closes the passage to the outside. The latter in its normal position is in a seat with a seal, pressed by a spring. The upper stop for the spring is a metal washer mounted on a rod, the end of which is screwed to a plastic handle. It is used to adjust the valve. The membrane and sealing elements are made of polymer materials, the spring is made of steel.

This whole simple mechanism works like this. In normal (standby) mode, as long as the coolant parameters are within the specified limits, the membrane closes the entrance to the inner chamber. As soon as a situation close to an emergency arises and the pressure in the heating system of a private house increases, the steam-water mixture begins to prop up the membrane. At a certain moment, the pressure force of the coolant overcomes the elasticity of the spring, opens the membrane, enters the chamber, and from it out through the side hole.

When some water leaves the system, the pressure will drop so much that it will not be able to resist the spring and the membrane will close the passage again. It happens that the mechanism operates cyclically, especially if the heating unit is operating at its limit and the coolant temperature is close to the maximum (90-95 ºС). In practice, when the burst valve for a boiler is triggered very often, it loses its tightness and begins to leak.

If you find fresh traces of leaks from the safety mechanism, then this is a clear sign that the heat generator is operating in extreme mode or that there is a malfunction in the heating system, for example, in the expansion tank.

Since not all manufacturers of heating equipment complete their products with a safety group, you often have to make the choice of a safety valve for the heating system yourself. To do this, it is necessary to study the technical characteristics of the boiler installation, namely, know its thermal power and maximum coolant pressure.

For reference. For most solid fuel heat generators famous brands The maximum pressure is 3 Bar. Exception - boilers long burning STROPUVA, whose limit is 2 Bar.

The best option is to purchase a valve with pressure control that covers a certain range. The regulation limits must include the value for your boiler. Then you need to select a product according to the power of the thermal installation, but it’s difficult to make a mistake here. The manufacturer's instructions always indicate the limits of the thermal power of the units with which a valve of a particular diameter can operate.

On the section of the pipeline from the boiler to the place where the relief valve is installed overpressure It is strictly forbidden to install shut-off valves. In addition, you cannot place the device after circulation pump, do not forget that the latter is not able to pump the steam-water mixture.

To prevent splashing of water throughout the furnace room, it is recommended to attach a tube to the outlet of the valve that drains the discharge into the sewer. If you want to visually control the process, then you can place a special drain funnel on the vertical section of the tube with a visible break in the stream.

Conclusion

The pressure relief safety device is considered very reliable due to its simple design. When making a choice, you should pay attention to the quality of the material and not chase a cheap product. No less important is correct setting valve by maximum pressure boiler installation.

Boiler equipment, whether it is a boiler in a private home or a large boiler room in an enterprise, is a source of danger. The water jacket of the boiler, which is under constant pressure, is potentially explosive.

To ensure safety, many protective systems and devices are installed on boilers and other heat generators produced today. One of the simplest and most accessible is an installed one. It is sometimes also called an explosion valve.

Causes and consequences of coolant overheating

The problem of increase is especially important for solid fuel boilers. An emergency situation usually occurs when the water in the circuit overheats heating boiler. As soon as the coolant heated above normal boils in the boiler tank, it instantly turns into steam. This is followed by a sharp increase in pressure in the heating system of such a steam boiler.

As a result of overheating of the heating boiler, the risk of destruction of fittings and polymer pipes increases. Leaks may begin at the connections of the system's pipelines, including pipe ruptures. The worst thing is a boiler explosion or an electrical short circuit in the boiler equipment.

What is a safety valve for?

Troubles associated with excess pressure in the heating system are extremely dangerous for people and buildings. To prevent severe consequences of overheating, explosion valves are installed. Since the source of the critical increase in pressure is the boiler itself, the valve should be located as close to it as possible. It is mounted on the heating supply pipeline.

Manufacturers of heating equipment often produce their products already equipped with safety groups - a pressure gauge and a relief valve. This group is usually built into the jacket of the heating boiler. If the purchased boiler does not have such equipment, you will need to install it yourself.

In what cases is a safety valve necessary?

Unlike solid fuel boilers, when using electric or gas boilers, explosion safety valves are not installed. These devices have their own automation, and inertia is almost completely absent. This means that as soon as the coolant temperature reaches the set point, the electrical element or geyser turn off on their own. At the same time, heating also stops, which eliminates the risk of overheating and, accordingly, an increase in pressure to critical values.

Solid fuel boilers, like furnaces with a water circuit, are systems in which the use of safety valves is mandatory. Whatever automation is installed in solid fuel heat generators, after heating the liquid in the network to the nominal value, the firebox will continue to raise the temperature for some time, although access to the chamber is blocked by a sensor and the flame begins to die out. This is how the effect of inertia manifests itself. When the temperature in the firebox reaches 90-95 degrees (limit values for most boilers), steam formation is inevitable. The consequence may be depressurization of the heating system or a boiler explosion.

If the system has a safety valve installed on the boiler, then an increase in pressure after the coolant boils will be prevented. The valve will independently release excess steam to the outside, reducing the pressure in the system to normal. After this, the valve will close and operate the next time only if the emergency situation repeats.

Safety valve device

The valve is made of plumbing brass using hot stamping technology. It consists of two parts that have a semi-solid state.

The main element of the valve is a special spring. Depending on its elasticity, the power of pressure that is applied to the membrane closing the exit to the outside is determined. The normal position of the membrane is in the seat, pressed by this spring.

With its upper part, the spring rests against a metal washer, which is mounted on a rod, the end of which is fixed to plastic handle. It is this that allows you to adjust the explosion valve. The sealing parts and the membrane itself are made of polymer. Steel spring.

Valve operating principle

While in standby mode, the entrance to the inner chamber is closed with a membrane. If an emergency occurs, the mixture of steam and water begins to push against the membrane, opening it at peak pressure. As a result, the steam-water mixture penetrates into the chamber and then exits through an opening on the side.

After the pressure decreases, due to a certain amount of water leaving the system, the membrane falls into place and blocks the outlet of water. Sometimes such valves operate frequently, especially when boilers are operating at maximum capacity. This is undesirable, since the boiler may lose its seal and therefore leak.

If traces of leakage from the safety valve are detected, it is necessary to urgently inspect the boiler and heating system, since its operation is a sign of operation heating system in extreme conditions. However, sometimes the cause of an emergency pressure release may also be expansion tank. Therefore, you definitely need to check it too.

In addition to the valve under consideration, the PGVU valve can also be used for dust and gas air pipelines. It has the same principle of operation. However, in the case of its use, it does not matter at all whether the boiler is a steam boiler or a solid fuel boiler, as well as what exactly will be thrown out - water, steam or gas.

How to choose a safety valve

If a valve is not supplied with the boiler, it will have to be purchased separately. The choice is made based on the characteristics that matter thermal power and the maximum possible coolant pressure in the heating system.

For reference. Most solid fuel boilers of well-known brands have a maximum permissible pressure of about 3 Bar, with the exception of products from STROPUVA. They have a limit of 2 Bar.

It is best to install a valve that provides adjustment in several ranges. Naturally, the values of the boiler installed in the boiler room must be within these ranges. After this, a valve is selected based on power - the boiler passport will help here, which always indicates the heat power limit of the unit.

It is strictly forbidden to install an explosion valve after the pump responsible for circulating coolant in the system. There is another rule. Shut-off valves must not be installed between the boiler and the relief valve.

Despite constant warnings from buyers of electric heating equipment that such devices must be installed strictly according to the instructions without ignoring all components, it still happens quite often that the safety valve for the boiler is not installed at all.

Safety valve device

The safety device consists of two parts:

Check valve

Burst valve

They are both located under one body and each performs its own function. The check valve prevents excess water (which appears as a result of heating the water) from flowing back into the system. The second valve, also known as the blast valve, is activated only if the threshold pressure value is exceeded, usually 7-8 bar.

Based on this information, it is clear that in the event of an emergency or a sharp increase in pressure, the blast valve will release excess water and prevent damage to the electric heater. It also has a lever for forced drainage of water, this is necessary when repairing or dismantling the boiler.

Although every water heater has thermostats that control the temperature, they can break, so a system that has a working safety device is safe and will serve you for many years.

There are also situations with a lack of water in the system, here the proper operation of the check valve, which is installed on the water heater, is very important, because all the water will come out of the water heater, and if the thermostat is faulty, the empty boiler will heat up very quickly and the heating elements inside will burn out.

Water leaking from valve

Water leakage is a common occurrence for a safety device, this indicates that it is working properly. But if the water is flowing too quickly or constantly, it may indicate one of these problems:

The spring stiffness is incorrectly adjusted;

System pressure is too high;

If to last problem If you have nothing to do with it, then the spring stiffness can only be incorrectly adjusted if you carelessly handle the adjusters.

Jumps in the system can be eliminated with the help of another valve - a pressure reducing valve; it is installed before the safety valve and ensures the supply of stable pressure to the water heater.

No water dripping from the safety valve

If after installing the boiler it does not work even once, even at maximum heating, you should think about the serviceability of the safety device. You shouldn’t change it right away; perhaps excess water is leaking through a faulty faucet, or there is damage to the pipes.

Sometimes the boiler is not heated to high temperatures, not higher than 40 degrees. In this case, the safety valve for the water heater does not work due to insufficient pressure build-up inside the boiler, this is normal.

Choosing the right model

Usually a safety device of the required model is included with the boiler. But if it is not there, it is faulty, or you replace it after some time of using the water heater, then you will have to choose the right one yourself.

The main parameter after the thread (the size is very easy to select, usually 1/2 inch) is the working pressure. From correct selection This parameter will determine the correct and safe operation of the boiler. The required pressure is indicated in the operating instructions that come with each water heater.

There are two problems that may arise as a result of incorrect selection of a safety device:

Constant leakage from the device due to the choice of a lower operating pressure than necessary;

The device will not work at all if a value greater than necessary is selected, such a safety valve will not save in the event of an emergency;

Correct installation of the safety device

1. First, disconnect the boiler from the power supply and drain the water from it.

2. We install the device for the cold water supply at the inlet of the heater. We pack it in the usual way and connect cold water to the second side.

There is an arrow on the valve body that indicates the direction of the water; when installed, it should point towards the boiler.

3. We connect the pipe that comes from the blast valve with the sewer. Sometimes it is purchased transparent in order to monitor the serviceability of the safety valve.

4. After connecting the boiler completely, it is worth checking it. To do this, fill the tank by prematurely opening the valve to allow air to escape.

5. Then, after drawing water, close the tap and turn on the boiler.

6. We monitor all joints for the presence of water and look at the functionality of the safety valve. If a leak is detected, the inlet and outlet valves are closed, and the desired area is repacked.

Can the safety valve be replaced with a non-return valve?

In no case, the safety device has a check valve inside it, but there is more than one, the blast valve should not be missed. If a check valve prevents water from flowing into the system and, roughly speaking, saves you money, then a blast valve prevents the boiler from increasing the pressure inside to critical.

A boiler that has a non-return valve installed instead of a safety valve is a time bomb. The enormous pressure inside the water heater will not destroy the boiler until you open the tap. When you open the tap, the pressure inside the boiler decreases, but water, heated to a temperature higher than 100 degrees, immediately turns into steam, destroys the walls of the boiler and rushes out.

This is a fairly strong explosion, which is accompanied not only by fragments of the body, but also by hot steam and water. Take care not only of yourself, but also of the people around you.

conclusions

Follow the operating instructions; even such a small-looking device makes your life safer. The safety device is very important element and operating the boiler without it is strictly prohibited. Always monitor the operation of the installed protective device, water flows from it when necessary or not. All these factors will save your time, money and health.

Boiler equipment

Explosive safety valves PGVU 091-80

Explosive safety valves are used to prevent the destruction of power plants in the event of an explosion of flammable gases, coal dust, etc. They are a hole (window) in explosive elements of power plants, closed with doors or materials (asbestos sheet, etc.) that are easily destroyed during an explosion. An explosion valve connected to gas outlets protects personnel from burns. Explosion valves are equipped with combustion chambers, gas ducts of steam boilers and furnaces, and dust preparation systems of boiler plants operating both under vacuum and at excess pressure.

We are also ready to manufacture explosive safety valves of non-standard rectangular cross-section with the development of technical documentation for rectangular gas ducts.

Method for calculating the cross-section of an explosion safety valve and recommendations for installation on a gas duct.

The dimensions of the explosion valves are determined by the boiler design.
Practical experience shows that the cross-sectional area of the explosion valve is taken at the rate of 0.05 m3 per 1 m3 of the gas duct:
Skl=0.05m2 x Vflue.
Based on the results obtained, the closest standard size of the explosion valve is selected.

Installation and operation of explosion safety valves must be carried out in accordance with the “Rules for Construction and safe operation steam and hot water boilers”, “Safety Rules in the Gas Industry” and other regulatory documents.
The explosion valve is usually installed on the gas duct between the boiler and the chimney, preferably before the gas-tight valve (a place of possible gas accumulation, especially if the gas-tight valve is accidentally closed).
Safety valves must be installed on dust-preparation equipment in such a way as to prevent personnel from being injured by the blast wave and the hot dust-gas mixture ejected from the valves. If it is impossible to install safety valves in places that are safe for operating personnel, bends must be used. To prevent accidents, supporting grids or cages with mesh should be installed not only when the valves are operating under vacuum, but also when operating under excess pressure.

LLC "PTE-87" industrial heat power engineering - supply of equipment

LLC "PTE-87" industrial heat power engineering - supply of equipment Boiler equipment Explosive safety valves PGVU 091-80 Explosive safety valves are used for

Flues, air ducts and pipeline parts

Bends, transitions, tees, explosion valves, gates, compensators, manholes, supports, umbrellas, deflectors.

Gas ducts, chimneys and air ducts (round and rectangular cross-section)

Efficient operation of the boiler is possible provided there is a continuous supply of air through the air ducts into the firebox, necessary for combustion of the fuel.

Details pipelines.

Series 5.903-13 Products and parts of pipelines for heating networks;
Series 5.900-7 Support structures and means of fastening steel pipelines;
Series 5.905-8;15; 18; 25 Knots and parts for fastening gas pipelines;
Series 4.903-10 Products and parts of pipelines for heating networks;
Series 5.904-41 General purpose check valves;
Series 5.904-42 Fire retardant check valves;
Series 5.904-50 Ventilation grilles;
Series 5.904-74.93 Unified ventilation designs air handling units(confusers, boxes, pipes, flanges, frames, valves);
And various other auxiliary devices.

Bends and transitions (concentric and eccentric).

Fig.2 Bends and transitions.

Fig. 3. Bends with bend angles of 15 o, 22 o 30’, 45 o, 60 o and 90 o

Rice. 4. Concentric transition Fig. 5. Eccentric transition

Designed to connect two or more pipelines into a single network.

Examples symbol tees.

Explosion valve (explosive safety valve). Flap valve.

Fig 8. Valve. A – explosion valve (explosive safety valve); B – flap valve.

Fig. 9. Explosive safety valve.

Shiber. Gate valve. Valve. Valve.

The gate is a valve-type locking device, with the help of which a channel for the movement of liquid or gas opens and closes. The damper is used in the chimneys of factory furnaces and boiler plants to regulate draft. Small gates are driven manually, large ones by means of gear racks, worm gears, etc.

Figure 10. Check valve.

Fig. 11. Square check valve.

Compensator.

Manholes are designed for internal inspection, repair and cleaning of tanks, gas ducts and other equipment where periodic inspection and repair are necessary.

Manhole LL-600 UHL1 TU3689-019-03467856-2001.

Figure 12. General view of the manhole LL-500/600/800:
1 - hatch cover; 2 - handle; 3 - reinforcing pad; 4 - bolt with nut; 5 - flange; 6 - gasket.

Assemblies and parts for fastening gas pipelines (supports, hangers).

In heating networks on pipelines, support structures are installed to absorb the mass loads of the pipeline (deformation and elongation during heating, dynamic loads from vibrations and shocks) and the working medium flowing through it, fittings, insulation and other devices located on it.

Movable supports are divided into sliding and roller and serve to transfer the weight of heat pipes and their insulating shells to supporting structures and ensure pipe movements that occur as a result of changes in their length with changes in coolant temperature. For pipelines with a pipe diameter of 200 mm or more, rolling bearings - roller, roller, ball - are used to reduce friction forces on the supports.

Fig. 13. Movable supports.

Figure 14. Fixed supports.

Fig. 15. Suspended supports (suspensions).

Umbrella, deflector, ventilation grilles.

Umbrellas are installed on ventilation shafts, with natural and mechanical propulsion, in order to protect the shafts from atmospheric precipitation. The choice of umbrella type is made in accordance with the outer size of the shaft neck.

Be smart!

;font-family:’Times New Roman"”>Explosion valves: purpose, installation locations

;font-family:'Times New Roman">To prevent the destruction of the enclosing structures of furnaces and gas ducts of thermal installations, in the event of possible explosions of gas-air mixtures, it is necessary to install safety explosion valves in them, which should operate at pressures lower than those that destroy the structures of pressure installations. These valves ensure timely release of the pressure of combustion products from the chamber where the explosion occurs. For steam boilers with a steam capacity of up to 10 t/h and hot water boilers with water heating temperatures up to 115ºC, the total area of the safety explosion valves must be at least 200 cm2 per cubic meter of internal volume firebox, flue or hog.Safety explosion valves are installed in the masonry or lining of the furnace, the last gas duct of the boiler or the gas duct of the water economizer, ash collector, gas duct before the smoke exhausters, horizontal gas duct after the smoke exhauster to the chimney.Various designs of safety explosion valves are used. The most common types of valves are burst, flap and relief valves. They are installed on the ceilings and walls of the firebox, flues and hogs. It is advisable to coordinate the installation location of the valves with the areas of the most likely accumulation of gas leaks, areas of formation of gas bags, and also position them so that when triggered by a blast wave, operating personnel are not affected. If the last condition cannot be met, it is necessary to have a protective box or visor after the valve, firmly attached to the unit and diverting the explosive exhaust to the side. The shape of explosion valves should be square or round, since in this case less pressure is required to rupture the membrane. The burst valve has a membrane made of sheet asbestos 2 ÷ 3 mm thick, which is destroyed during an explosion in the firebox. Through the formed hole, combustion products are discharged into environment and the pressure in the firebox and flues quickly drops. An asbestos sheet of such thickness is fragile and cannot withstand the dynamic load associated with changes in vacuum and pulsation in the chamber. To increase durability, a metal mesh with cells of 40×40 or 50×50 mm is mounted in front of the membrane on the firebox side. The asbestos sheet and mesh are clamped with flanges, which are attached to a metal box firmly mounted into the lining of the heating unit. It is also necessary to take into account that asbestos sheet has a certain heat resistance: it can work for a long time at temperatures up to 500ºC, and for a short time at 700°C. Therefore, explosion safety valves must be installed so that the asbestos membrane is not subjected to intense heating from the torch and hot masonry. Burst type valves are simple and inexpensive. However, during operation, the asbestos sheet is often destroyed by the effects of heat flows from the firebox. True, replacing the asbestos membrane is not difficult, since this is provided for in the design of the safety valve itself.

;font-family:’Times New Roman"”>Purpose of gas burners, their design.

;font-family:'Times New Roman';text-decoration:underline”>Burner;font-family:'Times New Roman"”> a device designed to supply gas to the combustion site, mix it with air and ensure stable combustion and combustion adjustments.Depending on the gas and air pressure, they are: low pressure gas up to 500 mm water. Art. (5 kPa), air up to 100 mm water. Art. (5-100 kPa), air 100-3000 mm water. Art. (10 kPa), air more than 300 mm water column (3 kPa).

;font-family:’Times New Roman"”>Gas burner types:

;font-family:’Times New Roman"”>Diffusion burner. ;font-family:’Times New Roman"”>A burner in which fuel and air are mixed during combustion.

;font-family:’Times New Roman"”>Injection burner. ;font-family:’Times New Roman"”> Gas-burner with preliminary mixing of gas with air, in which one of the media necessary for combustion is sucked into the combustion chamber by another medium (synonym ejection burner)

;font-family:’Times New Roman"”>Hollow premix burner;font-family:’Times New Roman"”>. A burner in which gas is mixed with a full volume of air before the outlets.

;font-family:’Times New Roman"”>Burner not with hollow premix;font-family:’Times New Roman"”>. A burner in which the gas is not completely mixed with air before the outlets

;font-family:’Times New Roman"”>Atmospheric gas burner;font-family:’Times New Roman"”>. An injection gas burner with partial pre-mixing of gas and air, using secondary air from the environment surrounding the torch.

;font-family:’Times New Roman"”>Special purpose burner;font-family:’Times New Roman"”>. A burner, the principle of operation and design of which determines the type of thermal unit or the features of the technological process.

;font-family:’Times New Roman"”>Recuperative burner;font-family:’Times New Roman"”>. A burner equipped with a recuperator for heating gas or air.

;font-family:’Times New Roman"”>Regenerative burner;font-family:’Times New Roman"”>. A burner equipped with a regenerator for heating gas or air.

;font-family:’Times New Roman"”>Automatic burner;font-family:’Times New Roman"”>. Burner equipped automatic devices: remote ignition, flame control, fuel and air pressure control, shut-off valves and controls, regulation and alarm.

;font-family:’Times New Roman"”>Turbine burner;font-family:’Times New Roman"”>. A gas burner in which the energy of the escaping gas jets is used to drive a built-in fan that forces air into the burner.

;font-family:’Times New Roman"”>Ignition burner;font-family:’Times New Roman"”>. An auxiliary burner used to ignite the main burner.

;font-family:’Times New Roman’;text-decoration:underline”>Gas burners

;font-family:’Times New Roman"”>Gas burners of all types have common elements:

;font-family:'Times New Roman"”>Nozzle (nozzles), which is designed to supply a certain amount of gas, and sometimes air at a certain speed, into the mixing part of the burner. A mixer, which is designed to form the combustible mixture necessary to ignite the torch, and are also designed to ensure a stable combustion process, preventing the flame from breaking away and slipping into the mixer. A burner nozzle (burner crater) with a stabilizing device, which serves to equalize the speed across the cross section after the diffuser, since the flow layer adjacent to the solid surface is slowed down and has a reduced speed, as a result of which flame breakthrough is possible along the periphery of the burner.The crater, which has the shape of a confuser, evens out the velocity field of the combustible mixture, which prevents flame penetration into the burner.

;font-family:’Times New Roman"”>Depending on the type of burner or its operating conditions, the elements take on different design, but basically they have the same purpose.

;font-family:'Times New Roman"”>A diffusion burner consists of a nozzle (which is also a burner nozzle) usually made of a metal or ceramic tube with a stabilizing device in the form of tides at the gas outlet holes. In pure diffusion burners there is no mixer and it is replaced by the volume of the firebox Mixing with the formation of a combustible mixture and combustion of gas occur in parallel in it.

;font-family:’Times New Roman"”>In an atmospheric ejection burner, sometimes called a single-wire burner, there are nozzles, a mixer, a burner nozzle and a stabilizing device at the outlet. The mixer consists of an inlet pipe, a mixing chamber and a diffuser.

;font-family:'Times New Roman"”>The inlet pipe (confuser-ejector) serves as a guide apparatus for injected air, helping to reduce hydraulic losses at the entrance to the mixing chamber. Pressure losses depend relatively little on the shape of the inlet pipe, so the pipe can be accepted simple conical shape.

;font-family:’Times New Roman"”>The mixing chamber (neck) serves to equalize the speed of mixing flows in front of the diffuser, the highest coefficient useful action which corresponds to a uniform velocity field in front of it. In addition, in the mixing chamber the concentrations of gas and ejected air are leveled to some extent (when creating a combustible mixture). It is advisable to give the mixing chamber a cylindrical or slightly tapered shape.

;font-family:’Times New Roman"”>Actions of the boiler room operator in the event of failure of one of the operating network pumps

;font-family:'Times New Roman"”>In this case, it is necessary to stop the boiler. Then cool it down. To do this, slightly open the emergency drain valve, while controlling the pressure in the boiler and the system and not allowing it to drop sharply, in order to avoid boiling water. And turn on the backup pump.

;font-family:’Times New Roman"”>Types and content of gas hazardous work carried out according to work permits

“>For the performance of gas-hazardous work, a permit-permission of the established form is issued, which provides for the development and subsequent implementation of a set of measures for the preparation and safe conduct of these works.

“> The organization must develop and approve the technical manager of a list of gas hazardous work, including those performed without issuing a work permit for production instructions ensuring their safe implementation.

“>At the enterprise, a list of gas hazardous work must be developed for each workshop (production).

“>The list must separately indicate gas hazardous work:

“>I – carried out with the issuance of an admission order;

“>II – carried out without issuing a work permit, but with mandatory registration such works before they begin in the journal;

“>III – caused by the need to eliminate or localize possible emergencies and accidents.

“>Gas hazardous work includes:

;font-family:’Times New Roman"”> – connection (insertion) of newly built external and internal gas pipelines to existing ones, disconnection (cutting) of gas pipelines.

;font-family:'Times New Roman">Connection of newly built gas pipelines to existing ones is carried out only before the gas is started up. All gas pipelines and gas equipment before their connection to existing gas pipelines, as well as after repairs, must be subjected to external inspection and control pressure testing (air or inert gases) by the team launching the gas;

;font-family:’Times New Roman"”> – start-up of gas into gas pipelines during commissioning, re-opening, after repair (reconstruction), commissioning of hydraulic fracturing, gas piping, ShRP and GRU;

;font-family:’Times New Roman"”> – Maintenance and repair of existing external and internal gas pipelines, gas equipment GRP, GRPB, ShRP and GRU, gas-using installations.

;font-family:’Times New Roman"”>When performing repair work in a gassy environment, you should use a tool made of non-ferrous metal that prevents sparking.

;font-family:’Times New Roman"”>The working part of the tool, made of ferrous metal, should be generously lubricated with grease or other similar lubricant.

;font-family:’Times New Roman"”>The use of electric tools that produce sparks is not allowed.

;font-family:’Times New Roman"”>The footwear of persons performing gas-hazardous work in wells, gas fracturing rooms, gas regulating stations, main gas stations should not have steel shoes and nails.

;font-family:’Times New Roman"”>When performing gas hazardous work, you should use portable explosion-proof lamps with a voltage of 12 volts;

;font-family:’Times New Roman"”> – removing blockages, installing and removing plugs on existing gas pipelines, as well as disconnecting or connecting gas-using installations to gas pipelines.

;font-family:’Times New Roman"”>When removing blockages in gas pipelines, measures must be taken to minimize the release of gas from the gas pipeline. Work must be carried out in hose or oxygen-insulating gas masks. The release of gas into the room is prohibited.;

;font-family:’Times New Roman"”> – purging of gas pipelines when turning off or turning on gas-using installations.

;font-family:'Times New Roman"”>When starting gas, gas pipelines must be purged with gas until all air is displaced. The end of purge must be determined by analysis or combustion of selected samples. The volume fraction of oxygen should not exceed 1% by volume, and gas combustion should happen calmly, without clapping.

“> When emptied of gas, gas pipelines must be purged with air or inert gas. The volume fraction of gas in the air sample (inert gas) should not exceed 20% of the lower concentration limit of flame propagation.

;font-family:’Times New Roman"”>When purging gas pipelines, it is prohibited to release the gas-air mixture into rooms, ventilation and smoke exhaust systems, as well as in places where there is a possibility of it getting into buildings or igniting from a fire source;

;font-family:’Times New Roman"”> – bypass of external gas pipelines, hydraulic fracturing, hydraulic registry, gas distribution and distribution, repair, inspection and ventilation of wells, checking and pumping condensate from condensate collectors;

;font-family:’Times New Roman"”> – digging in places of gas leaks until they are eliminated;

;font-family:’Times New Roman"”> – repairs with fire (welding) work and gas cutting (including mechanical) on existing gas pipelines, equipment for hydraulic fracturing, hydraulic fracturing, gas distribution and gas distribution.

“>Performing welding work and gas cutting on gas pipelines in wells, tunnels, collectors, technical undergrounds, gas distribution centers, gas distribution centers and gas distribution centers without turning them off, purging them with air or inert gas and installing plugs is not allowed. Before starting work on welding (cutting) the gas pipeline, as well as replacing fittings, compensators and insulating flanges in wells, tunnels, and collectors, the ceilings should be removed (dismantled). Before starting work, the air is checked for gas contamination. The volume fraction of gas in the air should not exceed 20% of the lower concentration limit of flame propagation. Samples should be taken in the most poorly ventilated areas.

“>5. The main causes of injuries during boiler maintenance

“>- expiration of service life and equipment malfunction;

“>- malfunction or absence of emergency protection, alarm or communication means;

“>- incorrect organization of work;

“>- ineffectiveness or lack of production control over compliance with industrial safety requirements when operating equipment;

“>- low level knowledge of managers, specialists, and maintenance personnel of industrial safety requirements;

“>- violation of technological or labor discipline, careless or unauthorized actions of work performers;

“>- deviation from the requirements of design and technological documentation;

“>- violation of regulations for inspection or maintenance of equipment;

“>- violation of repair regulations, low quality of repairs;

“>- use in the manufacture or repair of equipment of construction materials that do not correspond to the design.

The materials were collected by the SamZan group and are freely available

Be smart!

Be smart! ;font-family:’Times New Roman"”>Explosion valves: purpose, installation locations;font-family:’Times New Roman"”>To prevent destruction of enclosing structures

Explosion valve on the boiler flue

In practice, explosion safety valves are currently designed in the form of:

Membranes made of sheet asbestos, 8-10 mm thick, loosely laid horizontally on protruding elements of the boiler or brickwork, sealed around the perimeter with crumpled refractory clay. When an explosion occurs, the membrane is thrown away;

Membranes made of sheet asbestos 2-3 mm thick, fixed in a frame of corners and bursting in an explosion. Sometimes membranes with a thickness of 5-6 mm are used with the obligatory cutting of grooves 2-3 mm deep on them crosswise so that the thickness of the walls under the grooves does not exceed 2-3 mm. In this case, the membrane rupture occurs along the grooves;

A cast-iron hinged lid, insulated on the firebox side with firebricks or fireproof mass and hinged in a metal frame. When there is an explosion, the lid swings open on its hinges;

Slabs made from a mixture of refractory clay and asbestos, reinforced with metal mesh and covered with asbestos sheets. The plate is hinged in a metal frame and is folded back when it explodes. In some cases, such a slab is laid freely on the protruding elements of the boiler or brickwork of the flue with a seal around the perimeter with crumpled refractory clay. When an explosion occurs, the plate is thrown away;

Slabs made from a mixture of refractory clay and asbestos, reinforced with metal mesh and covered with asbestos sheets and roofing steel. The slab is attached in an inclined position to the frame using hinges and compacted around the perimeter with crushed refractory clay. When there is an explosion, the plate is thrown back;

A metal plate with edges bent around the entire perimeter, immersed in sealing sand seals (proposal by M. A. Nechaev). The plate is secured by a spring and a chain to the valve frame and is thrown away during an explosion;

A special metal membrane fixed in the frame and having two diagonal grooves. The thickness of the walls under the grooves is calculated for rupture under the pressure arising in the metal flue during an explosion.

Let us consider the design and operation of the main most widely used explosion valves, taking into account the requirements formulated above that they must satisfy.

Asbestos membranes no more than 2-3 mm thick, clamped along the contour with metal flanges, are installed on brick or metal gas ducts. On the side of the flue under the membrane, a mesh of metal wire with a diameter of 1 mm and cell dimensions of 50 X 50 mm is placed. This mesh gives the valve mechanical strength against possible contact with asbestos from the outside. The strength of the valve seal in the masonry is ensured by thrust legs made from corners welded to the frame.

Asbestos explosion safety valves are cheap and easy to manufacture, but during operation they can fail even in the absence of gas-air mixture explosions. One of the reasons for this is pulsation in the furnace and gas ducts of the boiler, which causes vibration of the asbestos membrane and its destruction at the points of attachment in the frame. To reduce the effect of vibration on the durability of the asbestos sheet, it is coated on the outside thin layer clay, which forms a hard crust, slightly increasing its strength and rigidity. Often, maintenance personnel, in order to avoid destruction of asbestos from vibration, increases its thickness to 8-10 mm or installs several sheets of 2-3 mm thick each. This leads to the destruction of the boiler masonry during an explosion of the gas-air mixture, since the strength of such a valve is, as a rule, greater than the strength of the brickwork.

The second reason for the destruction of asbestos valves is their improper placement in the firebox or the first flue of the boiler, where they are heated by the radiation of the flame or hot areas of the masonry. Long service installation of an asbestos valve is possible only if it is not subject to radiant heating and the moving flow of combustion products does not directly contact it. To do this, the asbestos valve is placed at the level outer surface boiler masonry or using a metal pipe is moved outward from the flue. The “gas bag” formed due to the thickness of the masonry and the height of the pipe creates a natural insulating layer between the flow of moving gases and asbestos. The higher the height of the nozzle, the more the stationary layer of gases under the membrane is cooled and the longer it lasts. However, the membrane, moved away by an opening in the masonry or a metal pipe from the inner surface of the volume in which the explosion occurs, will perceive the pressure created in it with some delay compared to the perception of the remaining enclosing surfaces of the chamber, especially if the epicenter of the explosion is shifted from the axis of the pipe . Consequently, a valve with a diaphragm extended outward is unreliable and cannot be recommended.

The third reason for the failure of asbestos valves is the presence of leaks both in the membrane itself and in the sealing of the valve in the masonry. Due to the vacuum in the firebox or flue, air penetrates through leaks and, if there is unburned gas in the combustion products and at the appropriate temperature, the gas burns out at the explosion valve, burning it out. However, even if there are no flammable components in the combustion products, the asbestos membrane still quickly fails, since due to the resulting flows of moving air, the stagnant protective zone is eliminated, creating a circulation of high-temperature combustion products that come into contact with asbestos and destroy it. It follows that the condition and density of asbestos explosive valves also determine the possibility of their long-term operation.

When choosing a location for installing valves, their design and temperature conditions in the chamber are taken into account. Thus, when using valves with asbestos membranes in the firebox or first flue of the boiler, to reduce the heating of the metal pipe, its internal surfaces are sometimes lined with refractory bricks. Valves located above other boiler flues are not lined.

Some manufacturers recommend asbestos membranes 5 mm thick with cross-shaped slots 2 mm deep for installation on DKVR boilers. If necessary, a protective casing is installed above the membrane. The upper removable part of the casing has handles. A raised, clamped membrane along the contour cannot ensure timely operation of the valve and cannot be recommended for use. When placing the valve above the firebox, it is advisable to use a free-lying asbestos-clay slab, and above the flue - an asbestos sheet resting on a grate or mesh. In both cases, compaction is carried out along the contour with crumpled clay, and the knockout structure is located, if possible, at the level of the internal surfaces of the boiler lining.

Various options for the placement and design of asbestos explosion valves on cast iron sectional boilers, according to the recommendations of Lengiproinzhproekt, in some cases the asbestos membranes described above with a thickness of 2-3 mm, fixed together with a support mesh in a metal frame, are used. However, most often valves are designed from 10 mm thick asbestos cardboard, under which a grid of the appropriate size is laid. The frame of the grille is made of wire d = 3 mm, and the grille itself with cell dimensions 50 X 50 mm is made of wire d = 1 mm. The grate and asbestos cardboard lie loosely on the section or lining of the boiler flue ducts. The top of the valve around the perimeter is sealed with crumpled clay. Such a valve operates at a minimum explosion pressure and completely frees the gases from escaping.

Mosgazoproekt, when installing valves on top of sectional boilers, instead of asbestos cardboard, uses metal mesh-reinforced tiles made of stamped clay with asbestos fringe, freely lying above the cast iron sections along the longitudinal axis of the boiler or above the first gas duct in the immediate vicinity of the firebox.

To seal, these valves are also coated around the perimeter during installation.

fireclay clay. The weight of the slab should be as minimal as possible. To avoid injury to personnel, it is advisable to fasten the knockout plate to the frame using a chain with a spring.

Valves, which are reinforced chamotte-asbestos boards, have sufficient heat resistance, and therefore their use in chambers with high temperature, for example in furnaces, is preferable to asbestos membranes.

The body of such a valve is a frame made of corners, to which a hinged lid is attached, made of a mixture of fireclay clay with asbestos chips and reinforced with a metal mesh for strength. The outside of the lid is covered with sheet asbestos and metal sheet. In the working position, the lid is located slightly inclined; during an explosion, it is thrown down. To ensure the required density, the valve is coated with crumpled clay around its entire perimeter.

While maintaining the calculated area of the explosion valve rectangular shape Regardless of the upper or lower location of the hinges, it is desirable that the height of the valve be as high as possible, which leads to a decrease in the required force for its operation. When installing the valve on the side wall and installing a protective metal outlet, always directed upwards, the valve, when activated, should not block the outlet cross-section, so as not to create additional resistance in the path of gases. Using a valve with lower hinges in this case allows not only to completely free the outlet cross-section, but also to reduce its resistance by using the open valve as a guide plane in the lower part.

In the case where the firebox or flue has an elongated shape, the relative efficiency of the valves located near the possible source of ignition increases especially. This means that in such gas ducts (for example, hogs), it is advisable to place not one, but several valves along the length, each of which can have a slightly smaller area, thereby ensuring the release of combustion products during an explosion through at least part of the valves. In addition, if such a gas duct has sufficiently high mechanical strength (for example, a flame tube, the length of which reaches 8-10 m), then, taking into account that the blast wave will move along it, it is advisable to place the valve directly opposite the end of such a gas duct, for example, at the rear the wall of the smoke rotary chamber of the fire tube boiler along the axis of each fire tube. Only if the fire-tube boiler is adjacent to the wall of the boiler room at the end and installation of valves on the rear wall is not feasible, they are placed in the ceiling of the same rotary chamber. On the second gas duct of a fire tube boiler, the explosion valves are located in its upper part so that they are located above the sections connecting the second and third gas ducts of the boiler. The displacement of the valve from the drum to the periphery of a steam boiler is associated with the need to thermally insulate the drum at least 100 mm below the water level in it at the location of the valve. The valves of fire-tube boilers, installed on the second flue and on the ceiling of the rotary smoke chamber, have asbestos membranes. It should be recommended to replace membranes clamped along the contour with free-lying asbestos or asbestos-clay plates sealed at the edges with crumpled clay. On the rear wall of the smoke chamber (option I) valves are installed in the form of reinforced plates made of refractory clay with asbestos.

The valve consists of a body, to which a tray is welded in the upper part along the entire perimeter, filled with fine-grained quartz sand. When installing the valve in a brick lining, four legs 6 from a 50X50X 5 corner are welded to the lower part of the body. The discharge part of the valve is a metal cover 2 mm thick, the bent edges of which are immersed in sand, which prevents air from suction into the gas ducts, which are under vacuum. To avoid injury to operating personnel, the cover is secured to the body with a chain and a spring. A valve of this design can only be installed on gas ducts in which the temperature does not exceed 400-500 ° C in order to avoid overheating and warping of the cover. If necessary, the lower surface of the cover can be covered with heat-insulating material. If the gas duct is metal, then the valve body is welded to it.

On brick flue ducts of boilers and boiler rooms (hogs), explosion valves are installed, depending on local conditions, on their vertical or horizontal surfaces. If the valve can be damaged during operation, the horizontal valve must be protected, and the vertical valve must be equipped with a hinged metal cover attached to the valve frame on hinges. It is necessary that when the valve is positioned horizontally, the lid opens completely freely by 180°, and when positioned vertically, it has lower hinges. If the valve has an enclosing casing, then for inspection and repair of the asbestos membrane there must be a gap at least 350 mm high, covered with a metal lift flap. The width of the gap should allow the new asbestos membrane to be easily inserted through it.

Considering the special strength of membranes clamped along the contour, it is advisable to use free-lying asbestos sheets or asbestos clay slabs in horizontal sections, and the same slabs with lower hinges in vertical sections.

In this case, to replace or repair a cassette valve, the cassette is removed from the casing or partially pulled out, and upon completion of this work it is inserted into the casing along the guides. The place where the front wall of the cassette comes into contact with the casing is compacted with crumpled clay. The operation of cassette explosion valves has confirmed their advantages over other designs. With short protective casing we can recommend placing in a cassette those lying freely on metal grill asbestos sheet (b = 10 mm) or asbestos clay slab with compaction around the edges with crumpled clay. With a high protective casing, a folding valve and a special pocket in the casing should be provided, where the valve is thrown back during an explosion.

If the chimney is located at some distance from the boiler room, then the explosion valves are installed on a hog outside the room. In this case, the valves must be protected from precipitation and surface waters, and are also securely protected from access by unauthorized persons. To do this, an asbestos explosive membrane is placed inside a protective metal casing that has a sloping hinged roof, and a fence made of metal rods is placed around the casing. In the area where the casing adjoins the hog, a cement blind area is provided for drainage of rainwater and melted snow.

From all that has been said, it follows that explosion valves will protect maintenance personnel from being hit by a blast wave or parts of the destroyed

equipment. To do this, it is necessary to ensure daily monitoring of the condition of explosion valves and their timely repair. It should be remembered that the presence of safety explosion valves does not. in no case reduces the requirements for operating personnel to strictly comply with all safety rules and operating instructions for boiler rooms. How smaller area explosion valve, clamped along the contour, and the more its shape differs from the circle or square, the greater the pressure required to destroy it and ensure the release of pressure from the chamber. For example, when the aspect ratio of rectangular glass (δ = 2 mm) changes from 1: 1 to 1: 2 and 1: 3, while maintaining a constant area, the force required for destruction increases by approximately 25 and 55\%, respectively (for glass dimensions 600 X 600 mm).

On boilers with a steam capacity of up to 10 t/h, the number of explosion valves, their sizes and location are determined by the design organization. They are installed in the lining of the furnace, the last gas duct of the boiler, the economizer and the ash collector. In this case, it is recommended to take the total total area of the valves at least 0.025 m2 for each cubic meter of volume of the firebox and flues. On boilers with a capacity of 10 to 60 t/h, explosion safety valves located in the upper part of the firebox or in the upper part of the boiler lining above the firebox must have a total cross-section of at least 0.2 m2. On each of the above gas ducts (except for the firebox), at least two explosion valves with a total cross-section of at least 0.4 m2 are installed. On boilers with a capacity of more than 60 t/h, operating on pulverized, gas and liquid fuels, the installation of explosion safety valves is not necessary. On small-sized water-tube boilers of power trains operating on liquid and gas fuel, it is allowed to install one explosive safety valve with a cross-section of at least 0.15 m2 in the firebox and at least 0.3 m2 in each gas duct.

Explosion valves may not be installed in the lining of boilers with single-pass exhaust gases, as well as in gas ducts in front of the smoke exhauster. On vertical cylindrical (single-pass) boilers, in cases where the chimney is not located directly above the boiler, it is advisable to install explosion valves on a horizontal section of the flue, as close to the boiler as possible.

The area of one explosion valve according to SNiP II-37-76 must be at least 0.05 m2. It should be noted, however, that it is not advisable to use valves with an area of less than 0.15-0.18 m2 on heating and industrial boilers.

Explosion valve on the boiler flue

Explosion valve on the boiler flue In practice, at present, explosion safety valves are structurally made in the form of: - membranes made of sheet asbestos, 8-10 mm thick, freely