Expressive tank for heating closed type: installation

The owner has multiple options when planning the installation of a water heating system in his own home. The type of system (open or closed) and the principle of coolant transfer via pipes (natural circulation through gravity-driven action or forced, requiring the installation of a special pump) are among the most crucial matters to consider.

Tank extension for closed-type heating installation

Every scheme has benefits and drawbacks of its own. However, these days, a closed system with forced circulation is preferred more and more. Along with being easier, faster, and more compact, this scheme offers several other operational benefits. A fully sealed expansion tank for heating—a closed installation type that will be discussed in this publication—is one of its key differentiators.

However, you must at least familiarize yourself with the expansion tank’s mechanism, working principle, and which model is best suited for a given heating system before purchasing one and installing it.

What are the advantages of a closed heating system

The most widely used principle of heat transfer is still unquestionably the fluid flowing through pipes with a high heat capacity, even with the recent emergence of many sophisticated appliances and heating systems. Although other fluids with a low freezing temperature (antifreeze) must occasionally be used, water is the most common fluid used as a thermal energy carrier.

The most common is water heating.

The coolant absorbs heat from the boiler (a stove with a water circuit) and distributes it to the necessary number of heating devices (convectors, radiators, and "warm floor" contours) that are installed in the space.

How should the kind and quantity of heating radiators be chosen? Even the most powerful boiler won’t be able to maintain a comfortable temperature in a room if the parameters of the heat transfer point don’t match. A special portal publication covers the process of accurately calculating the number of heating radiators required.

Yet, all fluids share certain physical characteristics. First of all, its volume increases dramatically when heated. Additionally, this substance is inconsistent, unlike gases, so any method must be used to compensate for its temperature expansion, with the free volume serving as a means of doing so. Simultaneously, it is imperative to guarantee that air does not settle into the Izv pipes’ contours during cooling and volume reduction, as this could result in the formation of a "cork" that impedes regular coolant circulation.

The expansion tank carries out these kinds of tasks.

There wasn’t much of a unique alternative in private construction; instead, an open expansion tank was placed at the system’s highest point, more than capable of handling the tasks at hand.

The open-type system’s scheme

Boiler for heating;

2-feed riser

3-an open tank for expansion;

4-radiator for heating;

5. A circulation pump, if desired. This example shows a pump node with a slot system and a round-up loop. It is possible to switch from forced to natural circulation, and vice versa, if needed or desired.

You might be looking for information on proper heating radiator installation.

Costs associated with circulation pumps

circulation pumps

Closed systems are totally sealed off from the outside environment. It keeps a specific pressure at which the installation of a sealed tank with a unique structure compensates for the liquid’s temperature expansion.

Features of a closed-type heating system that differ

The diagram’s tank, which represents position 6, is cut into the return pipe (position 7).

Seemingly, why "Garden"? If it meets all of its needs, an ordinary open expansion tank is considered a more straightforward and affordable option. He is definitely worth a little, and with the right abilities, making and cooking it on your own without the need for an extra metal container—like an old can, for example—is quite simple. P. In addition, there are instances of how to utilize outdated plastic canisters.

Expansion tank in open position

Does anyone have any spare cash to buy a sealed expansion tank? It appears that there is, given the numerous benefits of the closed heating system:

• Complete tightness absolutely excludes the process of evaporation of the coolant. This opens up the possibilities of applying, in addition to water, special antifreeze. Measure – more than necessary, if the country house is not constantly used in the winter, but “raids”, from time to time .
• In the open heating system, the expansion tank, as already mentioned, should be mounted at the highest point. Very often, an unheated attic becomes such a place. And this attracts additional troubles for thermal insulation of the container, so that even in the most severe frosts the coolant in it does not freeze .

You can tuck the expansion tank away in a discrete corner.

Additionally, practically any section of a closed system can have an expansion tank installed on it. The return pipe just before the boiler entrance is the best location for installation because the tank’s components won’t be as affected by the heated coolant’s temperature changes there. However, this is by no means a rigid rule, and if, for example, a wall boiler situated in the kitchen or hallway is included in the system, it can be installed so that it does not conflict with the interior design of the space and does not look out of place.

• In an open expansion tank, the coolant is always in contact with the atmosphere. This leads to constant saturation of fluid with dissolved air, which is the cause of corrosion activation in the circuit and in radiators, to increased gas formation during heating. Aluminum radiators are especially intolerant of this.
• A closed heating system with forced circulation is less inert – it warms up much faster when starting, much more sensitive to adjustments. Completely unjustified losses in the area of the open -type expansion tank are excluded.
• The difference in temperature in the supply pipe and in the return in the currents of the connection to the boiler is less than in the open system. This is important for the preservation and duration of operation of heating equipment.
• Closed scheme with forced circulations to create circuits requires a smaller diameter – there is a win in both costs for materials and in simplifying installation works.
• Open -type expansion tank requires control – to prevent overflowing when filling out, and to exclude the fall of the fluid level in it during operation below the critical mark. Of course, all this can be solved by installing additional devices, for example, float valves, overflow pipe, etc.P ., But these are extra difficulties. There are no such problems in the closed heating system.
• And finally, such a system is the most universal, as it approaches any type of batteries, allows you to connect the contours of a warm floor, convectors, thermal curtains. In addition, if desired, you can organize hot heat supply, mounting an indirect heating boiler into the system.

Just one major drawback exists. The "security group," which consists of an automatic air vent, a safety valve, and control and measuring devices (such as a thermometer and pressure gauge), is responsible for this. Instead, this is a technological expense that guarantees the heating system operates safely rather than a sign of wealth.

To put it succinctly, the benefits of a closed system are immense, and the costs associated with a sealed expansion tank seem entirely reasonable.

How the expansion tank for heating closed type works and how?

For a closed system, the expansion tank device is not very complicated:

Schematic of the device and a sealed expansion tank

Typically, the entire structure is housed in a cylindrical steel stamped case (pos.1) (some tanks have the shape of "pills"). A premium metal with an anti-corrosion coating is used in manufacturing. The exterior of the tank is enameled. Red-cased products are used for heating. (There are blue tanks; however, these are the water supply system’s batteries. Enhanced hygienic requirements are applied to all their details, and they are not intended for high temperatures.

On one side of the tank (pos. 2), a threaded pipe is installed in preparation for its entry into the heating system. Occasionally, fittings are included in the delivery kit to make installation easier.

A nipple valve (pos. 3) on the other side acts to pre-create the required pressure in the air chamber.

A membrane (pos. 6) divides the tank’s interior cavity into two sections for the cameras. There is a coolant camera (pos. 4) on the pipe’s side, and air (pos. 5) is on the other side.

The membrane has a low diffusion indicator and is composed of an elastic material. Her unique form allows for "ordered" deformation in response to changes in chamber pressure.

Work has a straightforward principle.

• In the initial position, when connecting the tank to the system and filling it with the coolant, the certain volume of the liquid through the pipe enters the water chamber. The pressure in the chambers is aligned, and this closed system acquires a static position.
• With an increase in temperature, the volume of the coolant in the heating system is expanded, accompanied and increased pressure. Excess fluid enters the expansion tank (red arrow), and bends the membrane (yellow arrow) with its pressure). In this case, the volume of the chamber for the coolant increases, and the air, respectively decreases, and the air pressure in it increases.
• With a decrease in temperature and reducing the total volume of the coolant, the excess pressure in the air chamber helps to move the membrane back (green arrow), and the coolant moves back into the heating system (arrow).

The "Security Group" valve ought to open and release extra fluid if the heating system’s pressure reaches a certain point. There are expansion tank models that come with their own safety valve.

Expandable tank mounted on a unique bracket

Tank models can differ in terms of their design elements. They can therefore choose to replace the membrane (a special flange is provided for this) or remain indifferent. The kit might include clamps or brackets to mount a tank to the wall, or it might come with stands with legs to set it on the ground.

They may also vary in terms of the membrane’s actual design.

Distinctions in the construction of expansion tanks featuring diaphragm (left) and cylinder-style membranes

The expansion tank with a membrane is visible on the left, as indicated by the diaphragm (which was previously discussed). These models are usually indiscriminate. The elastic material cylinder-shaped membrane (see drawing on the right) is frequently utilized. It is actually a water chamber. Such a membrane stretches and increases in volume as the pressure rises. These tanks have a collapsible flange that makes it possible to replace the membrane on its own in the event of a failure. But this does not alter the fundamental idea of work.

Video: The device of expansion tanks of the brand "Flexcon Flamco"

Prices for FlexCon Flamco Expressive Bucks

Expansion tanks Flexcon

How to calculate the required parameters of an expansion tank?

The primary consideration when selecting an expansion tank for a particular heating system should be its working volume.

Calculation by formulas

It is recommended that you install a tank whose volume is roughly 10% of the total volume of coolant that is circulating through the system contours. Nonetheless, you can perform a more precise computation – a unique formula exists for this purpose:

With × K / D, VB = V

The formula’s symbols are highlighted:

VB is the expansion tank’s necessary operating volume;

Vc is the heating system’s total coolant volume;

K is the coefficient that accounts for the coolant’s volumetric expansion during heating;

D: The expansion tank’s efficiency.

Where can I find the starting values? We comprehend the row:

1. The total volume of the system ( VWith ) can be defined in several ways:

• You can detect along the water meter, what total volume will fit when filling the system with water.
• The most accurate way that is used in the calculations of the heating system is the summation of the total volume of pipes of all circuits, the capacity of the heat exchanger of the existing boiler (it is indicated in passport data), and the volume of all heat transfer devices in the premises – radiators, convectors, etc.P .
• The most acceptable error gives the easiest way. It is based on the fact that to provide 1 kW of heating power requires 15 liters of coolant. Thus, the passport power of the boiler is simply multiplied by 15.

2. The temperature expansion coefficient (K), which is expressed as a tabular value. It varies nonlinearly based on the fluid’s heating temperature and the amount of additives that contain ethylene glycol, or antifreeze. The values are listed in the following table. The heating line is determined by calculating the heating system’s intended operating temperature. The percentage of ethylene glycol in water is calculated to be 0. For antifreeze, according to a particular concentration.

Heating temperature of the coolant, ° C	Glycol content, % of the total volume
0	10	20	thirty	40	50	70	90
0	0.00013	0.0032	0.0064	0.0096	0.0128	0.016	0.0224	0.0288
10	0.00027	0.0034	0.0066	0.0098	0.013	0.0162	0.0226	0.029
20	0.00177	0.0048	0.008	0.0112	0.0144	0.0176	0.024	0.0304
thirty	0.00435	0.0074	0.0106	0.0138	0.017	0.0202	0.0266	0.033
40	0.0078	0.0109	0.0141	0.0173	0.0205	0.0237	0.0301	0.0365
50	0.0121	0.0151	0.0183	0.0215	0.0247	0.0279	0.0343	0.0407
60	0.0171	0.0201	0.0232	0.0263	0.0294	0.0325	0.0387	0.0449
70	0.0227	0.0258	0.0288	0.0318	0.0348	0.0378	0.0438	0.0498
80	0.029	0.032	0.0349	0.0378	0.0407	0.0436	0.0494	0.0552
90	0.0359	0.0389	0.0417	0.0445	0.0473	0.0501	0.0557	0.0613
100	0.0434	0.0465	0.0491	0.0517	0.0543	0.0569	0.0621	0.0729

3. An additional formula must be used to determine the expansion tank (D)’sefficiencyvalue:

D equals Qm – Q b) / Qm + 1.

The highest pressure that can be used in the heating system is Qm. The product’s passport must contain information about the safety valve threshold in the "Security Group" that will determine this.

Qb is the expansion tank’s initial air chamber pumping. Additionally, it may be mentioned in the product’s documentation and packaging. You can switch it up by pulling through the nipple or by pumping with a car pump. Typically, it is advised to set this pressure between 1.0 and 1.5 atmospheres.

Calculator for calculating the required volume of the expansion tank

The article includes a special calculator where these dependencies are made in order to make the calculation process easier for the reader. After entering the requested data and clicking "Calculate," you will receive the expansion tank’s necessary volume.

The value that is obtained is minimal, and based on that, the model that has the closest indicators is chosen. In addition, rounding is only done extensively so that the extra volume is not unnecessary.

Lastly, depending on where the expansion tank is supposed to be placed—on the floor or attached to a wall—it will be possible to select the best option from the designed range of the designed volume that is being offered for sale.

Another subtlety exists. Certain heating boilers come with an integrated expansion tank. This does not negate the need for calculations, as there are instances in which the built-in tank’s volume is obviously insufficient. In this scenario, you will need to buy and configure an extra, whose working volume is equivalent to the discrepancy between parameter B’s and the system’s total calculated indicators in a built container.

Prices for expansion tanks Jiglex

Expande tank Jiglex

And one last thing. Installing an expansion tank with a minimum 15-liter capacity is recommended even for small coolant volumes if the heating system operates on the principle of compulsory circulation.

Expressive tank for heating closed type: DIY installation

Setting up an expansion tank on their own won’t be too tough for someone with plumbing experience. The diagram illustrates the idea behind its integration into the system:

Planned implementation of an expansion tank installation in a closed heating system

A section where the tee is packed is made on the return pipe (pos. 1), on the site, as near as possible to the heating boiler entrance (pos. 2), but usually – before the circulation pump (pos. 3). The installation technique varies based on whether metal, polypropylene, or metalllapastic pipes are used.

A ball crane (pos. 7) was packed into the most expansion tank (pos. 5) next to the pipe (pos. 6). It is required to guarantee that the expansion tank can be disconnected in the event that maintenance or preventive action is required. For the same reason, it makes sense to connect the united nut (designated as "American") between the tap and the tank (pos. 8). When the crane is in the operating position, it should be open all the time.

There is a pipe segment that connects the tap to the tee (pos. 9). Its length and configuration—the number of bends or turns—don’t really matter; it is typically made in the quickest and most practical route possible from the tank installation site to the return pipe.

Let us now examine the necessary maintenance for the tank itself.

Illustration	Brief description of the operation performed
	The tank was taken out of the factory packaging, prepared the necessary tools and accessories for work.
	On the threaded pipe of the expansion tank, if necessary, the adapter is packed. It is important to achieve exclusively reliable sealing of compounds. It is best to packet on the pac from the use of Unipak paste or using a special threaded thread (cord), saturated with a sealing composition (as shown in the figure)..
	The adapter will be tightened, and you can proceed to the installation of the crane. should immediately note that the shortage is allowed in the indicated example – the master does not install a detachable connection – the “American” between the crane and the tank. That is, if it is necessary to dismantle the tank with a closed tap, it will be very difficult to do. Recommendation to all installers – do not forget about this moment.
	A thread for pacing the crane is wound, ..
	… the crane is placed in place and tightened tightly. should immediately be provided that the “lamb” is in a position convenient to use after placing the tank on the wall.
	The transition to the pipe, the required configuration is mounted from the tap, in accordance with the compiled scheme of the general installation of the expansion tank. In fact, in this part, the work is completed.
	Now you can check the pressure in the air chamber of the expansion tank. Nipple is placed on its opposite side – almost exactly the same as on the road wheels. In many models, it is covered with a special plastic cap, which, if necessary, access to the valve simply unscrews.
	You can check the pressure by a car manometer. If it exceeds the indicators that were used in the calculation of the system, then you can shade it to the required level by pressing the valve stem. If you fail to pump up with insufficiency – a car pump is suitable for this.
	In the considered version, the tank already has devices for its placement, even in two versions – the legs for installation on a horizontal surface (blue arrows) and a mounting panel for hanging on the wall (yellow arrow). The tank is mounted in the selected place, and then connected by a pipe section with a tee cut into the return. on this installation can be considered complete.
	Another version of the tank, on the case of which there are no structural elements for fastening at the installation site. But they, as a rule, are included in separate details in the set of delivery.
	Usually this is a bracket – a mounting platform for attaching to the wall, and a long screw strip clamp.
	The summer of the clamp is straightening and stretching into the gap of the installation site.
	All this is done so that the protruding side of the tank falls into a special groove of the mounting platform (shown by arrows), and the clamp was higher than the side.
	After installing the tank in the installation site, the ends of the clamp are connected, tightened first manually ..
	.. and then – to the stop, using a screwdriver or key.
	In this form, the tank will be ready for suspension on the wall.
	Installation of plumbing reinforcement to the tank pipe is carried out in the same order as already mentioned above.
	Nipple is located openly, only with a dustproof plastic cap. Verification and pumping, if necessary, is no different from the previously considered option.
	By the way, usually the tanks go from the plant with pre -installed pressure in the air chamber, and you can immediately choose the necessary parameter. It is indicated on the packaging and in the technical documentation of the product. Further installation of the tank is carried out in a certain order – installation on the wall in the selected place and connecting with a pipe with a tee.

They need to open the crane and add coolant to the system after the final installation. The expansion tank installation is finished if there are no leaks found in the connecting nodes.

Video: inserting an expansion tank into the circuit of polypropylene pipes

The importance of having a trustworthy "security group" for a closed heating system with a hermetic expansion tank must be emphasized once more at the article’s conclusion. Installing a second pressure gauge close to the expansion tank makes sense if it is situated in an inconvenient spot for routine visual inspection; it will be much simpler to keep an eye on the condition of the entire system from here. The heating extensor can be found by clicking the link.

You might be curious to know more about what a bimetallic radiator is.

Afanasyev Evgeny, Chief Editor

The publication’s author is 15.09.2015.

In the world of home heating and insulation, installing an expressive tank for a closed-type heating system is a game-changer. This installation process is key to ensuring efficient and effective heating throughout your home. By opting for a closed-type system, you"re choosing a setup that minimizes heat loss and maximizes energy efficiency. The expressive tank plays a vital role in this setup, serving as a reservoir for hot water that"s circulated through your home"s heating system. Its installation involves careful placement and connection to the existing heating infrastructure, ensuring seamless operation and optimal performance. With the expressive tank in place, you can enjoy consistent warmth and comfort in your home while also reducing energy costs and environmental impact.

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Expressive tank experiment