Safety, explosion, bleed valve. As soon as it is not called, mixing various functions and purposes, without looking at the design and characteristics. Moonshiners still argue until they are hoarse about the need for a safety valve, despite the huge number of fatal accidents. Just type in a search engine: “explosion” moonshine still” to think seriously about this problem.
Theory
An alcohol-containing liquid is boiling in a cube. If the steam outlet is blocked, pressure will begin to build. At the same time, the boiling point of the liquid will increase. Energy generously pours into the cube and accumulates every second, but this process is not endless. Sooner or later, mechanical depressurization of the cube will occur. For example, a clamp will break and the lid will shoot into the ceiling. If it all ended there, then there would be nothing to discuss. Light kitchen renovations, replacing a chandelier are everyday matters.
However, after depressurization, the pressure in the cube drops sharply, as a result, all the accumulated energy is released and leads to a sharp, explosive boiling of the entire volume of the bulk (alcohol-containing liquid in the cube). The resulting alcohol vapor flies out of the cube, simultaneously taking with it a fair share of the bulk.
Danger in numbers
For example, there were 40 liters of raw alcohol in the cube; the excess pressure that blew off the lid was only 0.5 atmospheres, which is close to reality. As a result, approximately 10 liters of boiling raw alcohol will fly out of the cube and flood everything around, scalding people and pets. Approximately another 10 liters will turn into steam and instantly form an explosive concentration of alcohol vapor in the room. If the moonshiner is a poor student who neglects basic skills and worked on an open fire, the explosion will be immediate.
If the distiller was smart and worked on closed heat sources, for example, heating elements, but got confused and decided to quickly pull the plug out of the socket or simply flip the switch - an explosion will occur immediately after this from a small spark that jumped when the contacts were opened.
Well, if the owner was not in the kitchen at that moment and his not scalded body retained the ability to think, then he would slowly and carefully open all the windows, create a draft and, perhaps, avoid more severe consequences.
The consequences of the volumetric explosion are very impressive - a wall was blown out to the neighbors, a balcony block flew across the road. There are other miracles. When nothing happens directly in the kitchen, but the explosive mixture is ignited by a spark in the next room and destruction will occur there.
A bleed valve is needed to prevent this scenario. Alcohol vapor is not a gas; when released, it will not accumulate to an explosive concentration. Once in the air, alcohol vapor immediately begins to condense and settle on walls, windows, and floors. Fly into the hood or window. It will stink, warning the owner about an unusual situation. The likelihood of an explosion becomes much less, although this does not protect against fire.
As statistics show, large diameters of columns do not at all relieve their owners from the risks of working with fire and explosive liquids. This is the specificity of our hobby.
Safety valve parameters
The main danger when distilling moonshine is not the mechanical destruction of the parts of the apparatus itself, but the creation of an explosive concentration of alcohol vapors due to a sudden depressurization of the cube.
In practice, this determines the requirements for the safety valve.
During the second distillation, the pressure in the cube is 500 mm of water. Art. is considered an emergency, because it indicates flooding of the column. But should it be prevented with a bleed valve? Definitely not.
If the valve bleeds at 400 mm water. Art., then on the one hand the column will not sink, but on the other hand we will simply get an imitation of its normal operation. As soon as the valve is activated, the reflux will fall down, disrupting the careful separation of fractions. As a result, the output will be ordinary fortified moonshine, and not a distillate purified from impurities. The valve must not interfere or contradict technological processes flowing in the apparatus.
Let's take another example. When the pressure in the cube increases, the thermometer may shoot out and depressurization will occur - well, good, again it bleeds off excess without the threat of explosion. There is no need to install a valve to prevent this event; this should be treated as a backup system.
But if the lid of a saucepan or pressure cooker rips off, the exhaust will be instantaneous. Clamps, depending on the quality of workmanship, can fly off even at a pressure of 1 atm. This is already a subject of control. In addition, as shown above, depressurization even at an excess pressure of 0.5 atm. can create an explosive concentration of vapors in the room. Here's another point.
Conclusion: in order not to interfere with the settings of the column, the safety valve must operate at a pressure not less than double the emergency pressure - 1000 mm of water. Art. = 70 mmHg Art. = 9.8 kPa = 0.1 bar. The closer its operation is to 0.5 bar, the more severe the consequences will be in case of failure. That's all the logic.
Safety valves from different manufacturers
Let's start with the most illiterate and have no idea about the parameters of the processes in the device. Such manufacturers install burst valves from pressure cookers on their cubes. Note - not bleeders, but disruptive ones or, in other words, emergency ones.
Pressure cooker valve This cheap valve actually operates at a pressure of 1.2 to 1.5 atm. - the line of last hope for a pressure cooker. It is clear that for the purposes of distillation and rectification it is useless, since a broken clamp and an explosion are possible up to the threshold of its operation.
A working pressure cooker bleeder valve looks like this; it should not be confused with an emergency one.
Bleed valve The working valve in the pressure cooker maintains an excess pressure of 80-110 kPa (0.8-1.1 atm.). The safety valve is activated when a pressure forms inside the pressure cooker that exceeds the operating pressure by 50 kPa (i.e. at 1.6 atm), which can occur if the operating valve is clogged. Activation of the safety valve allows steam to escape from the pressure cooker and makes it safe to use. But not in our case. Its characteristics are, of course, closer to the required range, but not that much.
You can try to remake the emergency valve. To do this, you need to disassemble it, throw away the spring and the red ball. In place of the ball, install a weight weighing about 36 grams. This will reduce the response threshold to 700-1000 mm of water. Art., but even this alteration does not guarantee normal operation of the valve. The stem easily warps and the valve does not close, and after a dozen operations, the design, not intended for this mode, easily becomes dirty in the area of the silicone sealing ring and ceases to be airtight. As a temporary solution to the situation, this alteration has the right to life, but not for permanent use.
The use of safety valves from heating systems and other water heating equipment faces the problem of the inability to adjust the response pressure to the required value.
Safety valve for heating system As a rule, for these systems pressure above 1.5-8 bar (150-800 kPa) is considered emergency. For moonshine, these are completely prohibitive values. The principle of their operation is simple, but even replacing the springs with less rigid ones often does not give the desired result, since the valve simply ceases to press tightly against the seat.
Therefore, thinking equipment manufacturers were forced to develop their own valves that operate at a pressure of about 900-1000 mm of water. Art. (70 mmHg).
Option for the correct safety valve 
Option for the correct safety valve These are fairly simple valves with a low cost of about 350 rubles with spare membranes costing 40 rubles. They are installed on a standard fitting with a ½” thread.
How to make a safety valve for a moonshine still with your own hands
Let's take a closer look at the valve design.
Safety valve design We take an old hose from a shower or flexible hose and remove the nuts from it. We complete with a fluoroplastic gasket and a silicone gasket. The gasket can be taken from a beer cap. All that remains is to collect everything. True, it will differ from the original in that it has a washer with a groove for the membrane. The thickness of the membrane is 1 mm, and the grooves are 1.3 mm; with careful installation it will work.
There is another fairly simple and functional system for preventing problems associated with excess pressure. The idea is simple: a tube is put on the drain fitting, allowing you to fill (1) or drain (3) stillage. During the distillation process (2), this tube is placed 600-800 mm above the cube and discharged into the sink. The height of the bend of the tube above the stillage level determines the excess pressure in mm of water. Art., after which the liquid will begin to flow into the sink. Naturally, the drain valve must be open.
Overpressure prevention system Simple, reliable and allows for many modifications.
These inexpensive and uncomplicated devices allow you to avoid serious risks when brewing moonshine. Don't neglect their use.
Boiler equipment, be it 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 heating boiler circuit overheats. 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, there is an increased risk of destruction of fittings and polymer pipes. 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 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 began 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 a 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 the heating system operating 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. Thermal power and the maximum possible pressure of the coolant in the heating system matter.
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.
The safety valve for a water heater only appears from the outside to be a simple, insignificant device. Inside, it's a pretty advanced boiler protection tool.
How does a safety valve work?
So, we take a regular valve from a regular boiler.
Not all valves have a pressure release handle. It does not play any special role in the operation of the valve. So, periodically, once every six months, open and close to check functionality.
Let's take a closer look at what's inside. And inside there are 3 (three) independently operating valves.
1. The safety valve itself
2. Check valve
3. Bypass valve
Safety or blast valve
Its purpose is to prevent an accident. The safety valve consists of a metal rod with a plug at the end (1), a powerful spring (2) and a water discharge fitting (3).
How does it work? Yes, simple.
Let's say our valve says 6 bar. When heated, the water inside the boiler begins to expand. Since there is nowhere for it to go, the pressure inside the tank begins to increase. As soon as the pressure rises to 6 bar, the rod will compress the spring and excess water will flow out through the fitting. In reality, all this happens smoothly and water simply drains out through the fitting.
Check valve
It lets water into the boiler, but not back. Consists of a rubber plug (1), a plastic rod (2) and a spring (3). The spring in the check valve, unlike the safety valve, is weak. She only needs to fix the plug on the valve seat.
You should not expect from this valve the same precise operation as on water check valves. It is not faced with the task of maintaining reverse flow under pressure. It protects the boiler from unauthorized water leakage. Simply put, so that water does not drain from it in the event of an accident or lack of water in the supply line.
Bypass valve
An inconspicuous and very important valve. The bypass valve is a check valve stem (1) with a small spring (2). Opens at reverse side from the check valve. It sounds absurd, but it is true.
Let's try to figure out what's so important about it. There is a safety valve. Its task is to relieve pressure above 6 bar.
What happens to the boiler tank up to 6 bar? The water heats up and expands. The pressure is growing, although not critically: 4 - 4.5 - 5 - 5.5 bar. The boiler is not a rubber ball and its tank is welded from sheet steel, not tank armor. Naturally, deformation occurs. Buck is trying to inflate. Microcracks appear in the enamel and welding seams. I wish this extra pressure could be blown off somewhere on occasion.
And this is where the bypass valve comes to the rescue. How does it work? Apartment. The boiler is heating. The pressure inside him is growing. Turn on washing machine. She begins to draw water. The water pressure in the pipes drops slightly, the bypass valve sees this, opens and releases excess pressure from the boiler into the main line. The pressure in the tank is equalized to water pressure. The boiler continues to heat up. It doesn’t have to be a washing machine, it can be a toilet cistern or any faucet.
How can we sum it up?
The safety valve is the most important part of the water heater. Its presence and performance directly affects the service life of the boiler.
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. Dewatering 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 contamination. 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 | d0 | A | DZ | D.P. | DO | F | I | D | DZ | D.P. | DO | F | I | D | S1 | S2 | H |
| mm | mm | mm2 | mm | mm | mm | ||||||||||||
| DN value | passage nest | nest section | opening pressure | mass ca. | |
| d1 x d2 | d0 | A | P0 min | P0 max | |
| 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
From correct strapping electric water heater accumulative type(boiler) depends not only on the life of the equipment, but also on the safety of residents. That's how serious things are. And its correct piping is a safety valve for the supply water heater cold water.
What is it for?
Installing a safety valve prevents the pressure inside the device from increasing above the standard value. What causes blood pressure to rise? As you know, when heated, water expands, increasing in volume. Since the boiler is a sealed device, there is nowhere for the excess to go - the taps are closed, and there is usually a check valve at the supply. Therefore, heating the water leads to an increase in pressure. It may well happen that it exceeds the tensile strength of the device. Then the tank will explode. To prevent this from happening, they install a safety valve for the water heater.
Maybe there is no need to install a safety valve, but simply remove the non-return valve? At a sufficiently high and stable pressure in the water supply, such a system will work for some time. But the solution is fundamentally wrong, and here’s why: the pressure in the water supply is rarely stable. There are often situations when water barely flows from the tap. Then hot water pressure is forced out of the boiler into the water supply system. In this case, the heating elements will be exposed. They will heat the air for some time and then burn out.
But burnt-out heating elements are not the worst thing. It is much worse if they become hot, and at this time the pressure in the water supply rises sharply. The water that gets on the hot heaters evaporates, a sharp increase in pressure occurs - with a jerk - which leads to a guaranteed rupture of the boiler flask. At the same time, a decent volume of scalding water and steam escapes into the room under high pressure. What this could mean is clear.
How it works
It would be more correct to call a safety valve for a water heater a system of valves, since there are two of them in the device.
They are located in a brass or nickel-plated case, which looks like an inverted letter “T” (see photo). At the bottom of the housing there is a check valve that prevents the outflow of water from the water heater when the pressure in the system decreases. In the perpendicular branch there is another valve, which, if the pressure is exceeded, allows some of the water to be released through the fitting.
The working mechanism is as follows:
- While the pressure in the boiler is less than that in the water supply (when filling or when the tap is open), the check valve plate is pressed out by the flow of water. As soon as the pressure is equalized, the spring presses the plate against the protrusions of the body, blocking the flow of water.
- When the heating is turned on, the water temperature gradually increases, and with it the pressure also increases. As long as it does not exceed the limit, nothing happens.
- When the threshold level is reached, the pressure compresses the safety valve spring, and the outlet to the fitting opens. Some of the water from the boiler is released through the fitting. When the pressure drops to normal, the spring closes the passage and the water stops flowing.
Based on the principle of operation, it is clear that water will constantly drip from the fitting. This happens when the water heats up and the pressure in the water supply decreases. If you periodically see water on the fitting, then everything is working normally. But the draining liquid must be drained. To do this, put a tube of a suitable diameter on the pipe and secure it with a clamp. The normal operating pressure of the boiler is from 6 Bar to 10 Bar. Without mechanical fastening, the tube will be torn off in no time, so we select a high-quality clamp and tighten it well. Place the tube into the nearest sewer drain.
One more point: the tube for the fitting needs to be transparent and preferably reinforced (the so-called “herringbone”). Why reinforced is understandable - because of pressure, and transparent - to be able to monitor the performance of the device.
Types and varieties
If we are talking about conventional safety valves for a water heater, then they look almost the same, only the nuances differ. But it is these small details that are responsible for the convenience and safety of operation.
The photo above shows two safety valves with release levers. They are needed for periodic performance checks. The lever flag is lifted up. It pulls the spring behind it, freeing it to release water. This check should be carried out approximately once a month. You can also empty the boiler tank by raising the flag and waiting for everything to drain.
Design Features
The difference in the presented models is that the model in the photo on the left has a lever secured with a screw. This eliminates the possibility of accidental opening and full reset water.
Two more differences are striking. This is an arrow on the body indicating the direction of water movement, and an inscription showing what pressure the device is designed for. Seemingly minor details. But if you can figure out the direction of water movement (look in which direction the poppet valve is turned), then the nominal value is more difficult. How to distinguish, for example, whether it is 6 Bar or 10 Bar? Only checks. How will sellers differentiate them? No way. By boxes. What if they put it in the wrong box? In general, it is better not to take a valve without markings on the body. These are usually the cheapest of the Chinese designs, but the difference in price is not so great that it is worth the risk.
Safety valves - serviceable and not
Also pay attention to the shape of the water discharge fitting. The model on the left has a long fitting and has a non-linear shape. The hose fits on it quite easily and is long enough to install a clamp. The shape of the fitting on the model on the right is different - with a widening towards the end, but more importantly, the fitting is short. You can still pull the hose onto it, but the clamp is questionable. Unless you crimp it with wire...
The following photo shows the safety valves without a forced pressure release flag. The one on the left has a threaded cap at the top. This is a serviceable model. If necessary, you can unscrew the lid to remove clogs, scale and other contaminants.
The model on the right is the worst option. No markings, forced resets or maintenance. These are usually the cheapest available, but this is their only advantage.
For large volume boilers
All of the above models are suitable for water heaters with a volume of up to 50-60 liters. For boilers larger size There are other models available, many of which have built-in additional devices. Typically this is a ball valve and/or pressure gauge to control pressure.
The water drain fitting here has a standard thread, so there will be no problems with fastening reliability. Such devices already have a fairly high price, but their quality and reliability are much higher.
Not everyone likes appearance I like these devices. For those who attach aesthetics great value Very attractive devices are being produced. Their price, however, is comparable to the price of an expensive water heater, but it’s beautiful.
Is it possible to install other valves?
Sometimes, instead of a special safety valve for a boiler, a blast valve is installed, which is intended for the emergency release of heating water. Although their functions are similar, the main mode of operation is fundamentally different. The demolition should only work when emergency situations. It is designed for volley discharge of a large volume of liquid. It is not suitable for constantly bleeding small portions of water. Accordingly, it will not work correctly.
Another case is to install only a check valve. It will not allow water to drain when the pressure in the water supply decreases, but it will not save you from increasing pressure in the boiler. So this option doesn't work either.
How to choose and install
Select a safety valve for a water heater based on the pressure for which the unit is designed. This number is in the passport. The volume of the tank also influences the choice. They produce devices with operating limits of 6, 7, 8, 10 Bar. Basically, all units are designed for this pressure. So everything is simple here.
Installation is simple: flax tow or fum tape is wound onto the threads, after which the valve is screwed onto the pipe. Twist it all the way by hand, then another one or two turns using keys. It is much more important to choose the right place to install it. In this case, this valve is installed directly on the cold water inlet pipe.
Next there may be a check valve, which is also called a shut-off valve. But this is already reinsurance - the same device is available in the safety device, and often after the water meter at the inlet. The installation diagram is shown below. This is one of the normal options.
The diagram shows a ball valve. It is necessary to empty the tank before storing it for the winter (at dachas) or before dismantling it for prevention and repair. But more often they put it on a tee, which is screwed directly onto the inlet pipe of the water heater. A safety valve is screwed onto the tee from below, and a ball valve is placed in the side outlet.
Actually, these are all normal options.
Breakdowns, causes, elimination
In principle, the safety valve for a water heater has only two failures: water either often flows from it or does not flow at all.
First of all, it must be said that bleeding of water when heating is the norm. This is how the system is supposed to work. Water may also be released when the boiler is turned off, if the pressure in the cold water supply pipes is higher than the valve response limit. For example, the valve is 6 bar, and the water supply is 7 bar. Until the pressure drops, the water will be released. If this situation repeats often, it is necessary to install a reducer, and it is best to use water in an apartment or house, but there are compact models of reducers that can be installed at the entrance to the boiler.
How to check the serviceability of the valve? If there is an emergency reset lever, this is easy to do. With the boiler turned off, you need to lift the lever several times to release excess pressure. After this, the dripping stops and does not resume until heating begins.
If water continues to drain, the spring may be clogged. If the model is serviceable, the device is disassembled, cleaned, and then put back in place. If the model is not collapsible, you just need to buy a new valve and install it.
This is what the reducer looks like - to stabilize the pressure on the boiler
Constantly dripping water is unpleasant and hurts your wallet, but not dangerous. It is much worse if, when heating the water, you never see water in the pipe. The reason is that the valve is clogged or the outlet fitting is clogged. Check both options. If it doesn’t help, change the valve.
