Какое давление должно быть в расширительном бачке котла: Давление в расширительном бачке газового котла: нормы и способы регулировки

Давление в расширительном бачке отопления закрытого типа

При обустройстве отопительной системы необходимо уделять внимание абсолютно всем моментам, начиная от проектировки теплового блока и заканчивая его комплектацией. Среди всего многообразия функциональных элементов вакуумный расширительный бачок для отопления играет немаловажную роль в создании качественно работающего обогревательного оборудования. Благодаря этому аппарату осуществляется регулировка объема теплоносителя, что позволяет исключить разрыв тепловой магистрали, радиаторов и запорной арматуры.

Принцип работы и типы компенсаторных аппаратов

Если вы собираетесь обустраивать обогревательный блок в загородном доме, то бачок расширительный для отопления (экспанзомат) должен в обязательном порядке фигурировать в нем.

Схема работы компенсационного бака для отопления проста: при увеличении температурного режима теплоносителя, его объем (речь идет о воде, поскольку именно она чаще всего используется для обвязки обогревательных узлов) увеличивается. В силу того, что контур закрытый, жидкость не испаряется и не сжигается, что, в свою очередь, провоцирует увеличение давления в магистрали, которое необходимо уменьшить во избежание аварийной ситуации. Вот такая стабилизация давления в системе отопления именуется компенсацией и именно для этих целей используется  расширительный бак для отопления.

С этой статьей читают: Открытая система отопления с циркуляционным насосом

Виды экспанзоматов

До недавнего времени широко использовались обогревательные узлы, которые работали посредством гравитационной циркуляции теплоносителя, то есть без центробежных насосов. Для них устанавливались расширительные резервуары открытого типа. Но вместе с тем, такие приборы имели массу недостатков, поэтому сегодня их практически не применяют для обвязки тепловых блоков.

Расширительный бак отопления открытого типа

А все дело в том, что в открытые экспанзоматы попадал воздух, который провоцировал развитие коррозии на внутренних поверхностях теплообменников. Кроме этого, жидкость из системы регулярно испарялась, что требовало постоянного контроля ее количества, поскольку это могло привести к снижению эффективности функционирования всего обогревательного узла. Да и к тому же, такие баки должны располагается в наивысшей точке системы, что не всегда удобно и практично.

Современные же отопительные блоки характеризуются применением насосных установок и расширительных баков закрытого типа. В этом случае превосходство в том, что тепловой контур полностью герметичен.

Компенсатор закрытого типа

Схема работы мембранного компенсаторного резервуара системы отопления строится на следующем принципе: внутри него располагается мембрана, которая делит экспанзомат на две части. В одной половине находится воздух или газ, которые закачиваются в него под давлением. Тогда как за счет другой части осуществляется непосредственно регулировка количества жидкости. Мембрана для расширительного бачка выполняется из эластичного материала, что обуславливает сокращение воздушной камеры при попадании воды внутрь нее, давление в ней увеличивается, компенсируя тем самым повышенное давление в тепловом контуре. Когда же теплоноситель охлаждается, то происходит обратный процесс.

Экспанзоматы зарытого типа могут быть фланцевыми (со сменным мембранным блоком) и цельными (с несменной мембраной). Второй вариант является наиболее предпочтительным в силу выгодной стоимости. Но вместе с тем фланцевые компенсаторы по эксплуатационным характеристикам во много лучше, поскольку при разрыве мембраны ее можно без проблем заменить новой.

С этой статьей читают: Мембранный расширительный бак для отопления

Выбираем расширительный бачок

Выбор компенсатора системы отопления – дело достаточно важное, поэтому нужно отнестись к нему со всей серьезностью. Немаловажным аспектом выбора компенсатора является:

• тип – закрытый или открытый;
• типоразмер;
• свойства мембраны:
• устойчивость к диффузионным процессам;
• рабочая температура;
• эксплуатационный срок.

Все эти данные вы сможете узнать непосредственно в магазине, где будете приобретать экспанзомат.

Как рассчитать объем компенсатора?

Сперва определим зависимость требуемой кубатуры и параметров, которые на него влияют. При вычислении необходимо принимать во внимание тот факт, что чем больше будет объем теплового контура и чем выше максимально допустимый температурный режим будет в нем, тем размер компенсаторной емкости должен быть больше.

Итак, для определения объема расширительного бака можно использовать следующую формулу:

• К_ов – коэффициент, который показывает размер увеличения кубатуры теплоносителя при его нагреве.

Согласно данным исследований, на каждый 10°С повышения температуры воды в магистрали становится на 0,3% больше. В упрощенных расчетах используется показатель в 5%. В том случае, если по тепловому контуру циркулирует нерзамерзайка (антифриз), то это значение будет составлять от 8 до 10% в зависимости от типа незамерзающей жидкости.

• V_вк – объем воды в магистрали.

Эти данные берутся из расчетов проекта, которые выполнялись на этапе составлении схемы обогревательного узла. В том случае, если вы не владеете такими данными, то придется определять кубатуру теплоносителя самостоятельно. Это можно сделать путем слива жидкости из трубопровода. Количество воды измеряется ведрами или расходомером, который устанавливается на потоке.

• Р_дк – максимально допустимое давление котла и всего контура в целом. Это значение берется из паспортных данных нагревательного элемента.
• Р_дб – показатель давления в воздушном отсеке регулятора, которое указывается производителем в техническом паспорте агрегата.

По результатам расчета вы получите точное значение.

К полученному значению специалисты рекомендуют прибавлять к полученному значению еще 3-5 единиц. Это позволит избежать нестандартных ситуаций, когда кубатура воды в магистрали будет по той или иной причине увеличена.

Монтаж и обслуживание экспанзомата

Монтаж расширительного бака системы отопления выполняется по всем правилам установки подобного оборудования, которые регламентируются проектом и инструкцией производителя техники. Установка компенсатора открытого типа осуществляется в наивысшей точке тепловой магистрали. Тогда как закрытые резервуары размещаются в любом месте, но не непосредственно после насосной установки.

При монтаже компенсирующих емкостей необходимо уделить особое внимание его крепежу, поскольку его масса вместе с жидкость достаточно велика.

Как правило, подобная техника комплектуется всеми необходимыми крепежные элементами, однако, согласно отзывам пользователей, они далеко не всегда способны обеспечить надежную фиксацию бачка.

Кроме этого, во время монтажа этого функционального прибора стоит задуматься и о том, что вам должно быть удобно им пользоваться.

Особенности обслуживания компенсирующей емкости

• регулярные проверки на наличие коррозии, вмятин и подтеков – не реже одного раза в 6 месяцев;
• проверка начального давления газового пространства на соответствие расчетному показателю – не реже одного раза в 6 месяцев;
• проверка мембраны на предмет обнаружения деформаций и повреждений — не реже одного раза в 6 месяцев;
• хранение неиспользуемого бачка осуществляется в сухом месте.

Вот, собственно и все тонкости устройства этого функционального оборудования. Надеемся, эта публикация поможет вам обустроить жилье эффективно работающей отопительной системой.

ВИДЕО: Обзор расширительных баков объемом 2-12500 литров с фиксированной и сменной мембранами и автоматические расширительные системы, управляемые компрессорами

90000 What Pressure Should My Boiler Be? Making Sure Your Boiler Will Work 90001 90002 90003 90004 90002 Why does the boiler pressure matter? 90004 90007 Most central heating systems are closed. This means that there are no open vents to accommodate the expansion and contraction of water as it heats and cools. Instead, the system is sealed and pressurised to make up for these changes. The pressure is crucial to your heating operating properly. 90008 90007 Most boilers have a way of detecting if the pressure is off.They will cut out when the pressure falls too low and some models do the same when the pressure is too high. So if the pressure is too low, your boiler will turn off and you will not have any hot water. Alternatively, high boiler pressure puts unnecessary strain and the system could break down. 90008 90007 90012 90008 90002 What pressure should my boiler be? 90004 90007 Generally, your boiler pressure should be between 1 and 2 bar. However, read your boiler’s manual or ask your heating engineer for the required pressure for your particular model.90008 90007 To check your boiler’s pressure, you need to locate the pressure gauge on your boiler. If there is the correct amount of pressure in your system, the needle should be between 1 and 2 bar. This area is usually designated in green. Below 1 and greater than 2 is in red, indicating critical zones. 90008 90007 Some boilers have a pressure gauge with 2 needles-the red needle serves as a marker while the black one shows the actual pressure. If the system has the right amount of pressure, the 2 should be pointing to the same number.Other boiler models have an LCD display showing the water pressure. 90008 90007 90023 90008 90002 What if my boiler pressure is too low? 90004 90007 If the boiler pressure falls below 1, you’ll need to top up your system. The steps to do this will vary according to the specific boiler model so consult your boiler’s instructions. However, in general, you’ll be doing the following: 90008 90029 90030 Turn off your boiler and wait for the system to cool. 90031 90030 Use the filling link or loop.There are 3 types: 90029 90030 External: Attach the filling loop to the corresponding valves and slowly move the lever. Keep doing so until the pressure needle moves into the green zone. Disconnect the external filling loop. 90031 90030 Keyed filling link: Insert the internal filling key into the loop and twist until it is closed. Turn the nearby knob so that water starts filling into the heating system. Do this until the pressure needle moves into the green zone. Turn the knob back to its original position and remove the key.90031 90030 Keyless filling link: Simply move the filling lever until you hear water entering the heating system. Keep the lever lifted until the pressure needle moves into the green zone. Release the lever. 90031 90040 90031 90030 Turn on your boiler and check to see if the pressure holds. 90031 90040 90007 If after all this, you still find that the pressure falls below the recommended amount, there could be a problem with the gauge or with your heating system. At this point, you’ll need to call a registered heating engineer to inspect and service your central heating system.90008 90007 90048 90008 90002 What if my boiler pressure is too high? 90004 90007 If the boiler pressure is above 2 bar or the needle is in the red zone, you’ll need to release some of that pressure. The best and easiest way to do this is to bleed 1 or a few of the radiators in your home. 90008 90029 90030 Turn off your heating system. 90031 90030 Place a radiator key or flathead screwdriver into the top valve. Turn the valve anticlockwise. 90031 90030 At first, air will escape. After that, water will start to flow out of the valve.Catch the water in a small bowl or absorbent rag. 90031 90030 Keep an eye on the pressure gauge while you do this. Keep the valve until the pressure needle falls back down into the green zone or between 1 and 2 bar. 90031 90030 Close the valve. 90031 90040 90007 90067 90008 90002 When should I check my boiler’s pressure? 90004 90007 Usually, the pressure should remain relatively stable so you do not need to check it every day or week. Instead, it is a good idea to check on your system’s pressure at least once a month.90008 90007 If the heating season has just begun, then check your boiler pressure to ensure that it will work properly for the upcoming winter months. Also, if you bleed any radiators, check the boiler pressure to make sure that it has not fallen too much. 90008 90007 90076 90008 90002 Need help regarding your boiler’s pressure? 90004 90007 Then do not be afraid to contact a professional heating engineer! 90081 Get in touch with up to 6 heating companies at once to easily compare their profiles, services, and prices 90082.You are able to ask any question you have about your boiler’s pressure and get a second (or third, or fourth, etc.) opinion. You’ll get the best information on how to maintain your heating system properly! 90008 .90000 What Pressure Should My Boiler Be? 90001 90002 90003 90004 90002 To have a well heated home, your boiler needs to be able to circulate hot water. To do that it needs the right amount of pressure. With this guide, you’ll know what pressure your boiler should be and what to do if it’s too low or too high. 90004 90007 90002 90009 Get FREE boiler quotes 90010 90004 90012 Get free quotes to supply and fit a new boiler now.90002 90004 90007 90016 What’s the Correct Boiler Pressure? 90017 90002 There are so many different boiler models so the correct pressure will not be exactly the same for all of them. Generally speaking, the pressure should sit between 1 and 2 bars. You should consult your boiler manual to find out if this is the case for your system. 90004 90002 You can find out the pressure of your boiler by looking at the built-in pressure gauge which is often on the front of the boiler. It’s a little needle housed in a semi-circle pointing at numbers and sometimes little green and red sections.90004 90016 Why is Boiler Pressure Important? 90017 90002 Without the correct boiler pressure, your system will not be able to circulate hot water around the pipes and to your radiators. The pressure should be constant in order for the boiler to operate effectively. 90004 90016 My Boiler Pressure is Too High 90017 90002 You can recognise high boiler pressure by seeing if the needle on the pressure gauge is either over 2 or in a red zone. To get the boiler pressure back down, you should bleed at least 1 of the radiators around the home — if you’ve spotted that some are not heating up properly, then they’re the radiators to bleed.90004 90002 A boiler constantly running at a high pressure could lead to the system failing or even end up damaging your home. So if bleeding your radiators does not do the trick then you should contact a qualified engineer. 90004 90016 My Boiler Pressure is Too Low 90017 90002 When the needle on the pressure gauge drops below 1, the boiler pressure is too low. You can get the pressure back up by re-pressurising the system, which you can find out how to do in our guide to low boiler pressure.90004 90002 Many systems will shut off when the pressure drops too low, leaving you without heating and hot water until it’s back up and running. So it’s good to get into a little routine of keeping a regular eye on your boiler pressure. 90004 90016 Why Does Pressure Rise as the Boiler Heats up? 90017 90002 As water gets hotter it expands so when the heating is on, water expansion causes pressure to build-up in the system. This will cause the reading on the pressure gauge to increase, which is nothing to worry about.90004 90007 90002 90009 Get FREE boiler quotes 90010 90004 90012 Get free quotes to supply and fit a new boiler now. 90002 90004 90007 90016 How Often Should I Check the Boiler Pressure? 90017 90002 Checking the boiler pressure is not something that you have to be doing daily, just aim to keep an eye on it around once a month. To get an accurate reading, take the reading when the boiler is not in operation. 90004 90002 There are a couple of important times to check your boiler pressure to make sure it has not dropped too low though.90004 90002 90058 Bleeding radiators 90059 90004 90002 If you find that one or more of the radiators in your home are not heating up properly then there might be air in the system and it will need bleeding. Once you’ve bled the radiators, check that the boiler pressure has not dropped. If so then you’ll need to repressurise the system. 90004 90002 90058 After summer 90059 90004 90002 When we enter the colder winter months, you’ll want to know that your boiler is ready for the higher heating demands so check that the pressure is not too low.90004 90002 90058 Boiler pressure dropping 90059 90004 90002 If your boiler keeps losing pressure after being topped up, this suggests that there’s a leak somewhere in the system. Take a look around the home for any damp patches that could be caused by a leak but do not go looking inside the boiler itself, this should always be done by a qualified engineer. 90004 90016 Still Having Trouble with Your Boiler Pressure? 90017 90002 If your boiler pressure keeps dropping then there’s likely to be a fault with the system and should be checked out by a qualified engineer.By filling in one of our simple forms right here on Boiler Guide, you’ll get free quotes from up to 3 trusted engineers in your area. No hassle, no-obligation, just free quotes. 90004 90007 90002 90009 Get FREE boiler quotes 90010 90004 90012 Get free quotes to supply and fit a new boiler now. 90002 90004 90007 .90000 Hydronic circuit purging: The basics 90001 90002 90003 Nearly all closed loop hydronic heating and cooling systems are supposed to be filled with water, or a mixture of water and antifreeze. The only intentional air in the system is contained in the expansion tank. 90004 90002 The only exception to the above is a closed-loop, drainback solar thermal system where a volume of air is captured and managed within the system. That air is repeatedly used to replace water in the solar collectors when they drain at the end of each solar collection cycle.90004 90002 Contrast the idea of ​​a fluid-filled system with the fact that it begins its service life completely filled with air. Transitioning a newly-minted hydronic system, or an older system that has been drained, from air-filled to water-filled is called «purging.» The effectiveness of purging plays a major role in reliable and efficient system operation. 90004 90002 Nearly all modern hydronic systems rely on two methods to get air out and move water into the system. The first is called «forced fluid purging,» the second is «microbubble elimination.»Together these methods can get the system up and running quickly and ensure that it remains essentially air-free over its full service life. 90004 90002 90012 THE OLD DAYS 90013 90004 90015 90002 Figure 1 90004 90002 Getting air out of hydronic systems was not always straightforward. When I began working with these systems in the late 1970s, the common method of purging was to fill the system from the bottom up, counting on air to exit at multiple air vents, or at «bleeder» valves on heat emitters, or at other high points in the piping.90004 90002 Imagine a scenario where several fin-tube baseboards each have a baseboard tee and a manually operated bleeder valve at the end of the fin-tube element. Figure 1 shows these fittings and how each is typically installed. 90004 90002 The installer opens all the bleeder valves before allowing water into the system. Pressurized water is introduced into the lower portion of the system by opening the «fast fill» lever on the system’s pressure reducing valve, or by opening a ball valve that bypasses the pressure reducing valve.Driven by the pressure of the building’s plumbing system, the water races through the piping, eventually gets to the open bleeder valves and sprays out tiny holes in the side of these valves. 90004 90024 90002 90026 90012 Related: Keep heat produced by auxiliary boilers out of thermal storage 90013 90029 90004 90024 90002 The trick is to catch those streams of water before they make a mess. That is pretty hard to do when the water is squirting out of four or five bleeder valves simultaneously at several locations in the building.If the hole in the bleeder valve faced outward, you could, in some cases, put a coffee can in front of each valve and hold it in place with a piece of wire. Still, this is a tedious approach to purging. 90004 90002 Even after the majority of the bulk air in the system is removed, the dissolved molecules of oxygen, nitrogen and other trace gases in the water take time to merge into bubbles that are large enough to be captured and ejected from the system by cast iron air scoops. 90004 90036 90002 Figure 2 90004 90002 Older methods of purging that mostly relied on getting air out at the system’s high points were slow and inefficient.90004 90002 Today, the hydronics industry has new hardware and methods that allow fast and efficient removal of air as the system is filled with water. One of the modern hardware devices that is now used routinely is the purge valve, an example of which is shown in Figure 2. 90004 90002 Purge valves combine two ball valves into a single body. One ball valve is inline with the piping being purged, the other is located in a side drain port that ends with a male hose thread and cap. 90004 90002 When used in a single circuit hydronic system, a purge valve should be installed as shown in Figure 3.90004 90002 90012 BULK AIR REMOVAL 90013 90004 90051 90002 Figure 3 90004 90002 To fill and purge the circuit, close the inline ball on the purge valve, open the side port ball and connect a hose to the side port as shown in Figure 3. Open the fast fill lever on the system’s pressure reducing valve and if a bypass ball valve is installed as shown in Figure 3, open it. 90004 90002 Pressurized water from the building’s cold-water plumbing enters the system just downstream of the purge valve and flows through the circuit in a clockwise direction based on the layout in Figure 3.The closed inline ball in the purge valve prevents the water from «short circuiting» to the drain port. 90004 90002 The key to good purging is to create high water flow velocity through the circuit. I suggest a water velocity of at least four feet per second through the piping during purging. This allows the water to act like a liquid piston, pushing most of the air in the piping and components ahead of it and eventually back to the purge valve. The air then exits through the side port of the purge valve.Within a few seconds, the water stream follows the air out of the side port and through a hose leading to a capture bucket or drain. The system’s circulator can be turned on at this point to further increase flow velocity though the circuit. 90004 90024 90002 90026 90012 Related: Step-by-step prep: Preparing condensing boilers for winter 90013 90029 90004 90024 90002 Once the existing water stream is free of visible bubbles for several seconds, the side port of the purging valve is closed.The system pressure will immediately climb as building water pressure pushes more water into the system and compresses the diaphragm in the expansion tank. It is important to close the fast-fill bypass ball valve on the cold-water inlet piping within a second or two of closing the side port of the purging valve. If you do not, it is likely that the circuit pressure will exceed the rated pressure of the pressure relief valve, allowing water to be ejected from the latter. If this happens, crack open the side port of the purging valve until the system drops to the desired static pressure.90004 90002 The process described will quickly remove most of the bulk air initially in the system. My experience has been that using this forced fluid purging approach eliminates the need to bleed air from high point vents. The fast moving water can force air through the system in any direction, including straight down, and eventually out of the purge valve. 90004 90002 90012 FINAL SCRUB 90013 90004 90002 The process of properly «deaerating» a hydronic system does not end with forced fluid purging.The cold water that now fills the system still contains between two and four per cent dissolved gas molecules, including oxygen, nitrogen and small amounts of other gases. You can not see this molecular «air,» but it will come out to play once the water is heated. Well-designed systems stand ready to quickly capture it and eject it. 90004 90002 The system shown in Figure 3 also includes a microbubble air separator. This device contains a coalescing media that coaxes the dissolved gas molecules to form tiny microbubbles.The coalescing media also provides pathways for these microbubbles to rise above the active flow zone in the separator and merge together at the top. After a small volume of air collects in the upper portion of the separator it is ejected through a float-operated valve. The pressure within the system is what pushes the captured air out. 90004 90002 Microbubble air separators are a tremendous improvement over legacy cast-iron air scoops and, in my opinion, should be used in every modern hydronic system.90004 90002 Coaxing dissolved gases out of the system fluid takes time, sometimes several days. The efficiency of dissolved gas removal is greatly improved if the system fluid is heated. Hot water (or hot antifreeze solutions) can not retain as much dissolved gas as cool water and give up dissolved air more willingly as it passes through the air separator. Eventually the microbubble air separator, in cooperation with an automatic make-up water system, or an automatic fluid feeder, reduces the air content of the system to an insignificant level and keeps it there.90004 90002 90012 MULTIPLE ZONE SYSTEMS 90013 90004 90088 90002 Figure 4 90004 90002 Most modern hydronic systems are not as simple as the one shown in Figure 3. These systems contain multiple zone circuits, or other parallel piping paths. The most efficient way to purge the systems is to install a purging valve on the return end of each circuit, as shown in Figure 4. 90004 90002 The purging procedure is very similar to that previously described. What is different is that each zone circuit is purged one at a time.Doing so produces the highest possible flow velocity through each circuit and the most efficient bulk air removal. When the purging valve on one zone return has a bubble-free return flow, close the inline ball on the purging valve and stop the cold water at the make-up water system. 90004 90002 Move the hose to the next purging valve and repeat the procedure. Keep doing this until each zone is purged. After water is forced into each zone, the zone circulator can also be turned on to further increase purging velocity.The microbubble air separator will do the final cleanup by capturing dissolved gases and ejecting them from the system. 90004 90002 90012 P / S PURGING 90013 90004 90101 90002 Figure 5 90004 90002 In the case of primary secondary systems I recommend using a purging valve on the return side of each secondary circuit as shown in Figure 5. 90004 90002 This approach eliminates the need for a ball valve between each set of closely spaced tees-the sole purpose of which is to force water through the secondary circuit during purging.The combination of the purging valve on the return side of the secondary circuit, along with isolation flanges on each secondary circulator, allows each secondary circuit to be completely isolated for service if necessary. 90004 90002 Start the purging procedure by isolating all secondary circuits, then purge the primary loop using the previously described procedure. Once the primary loop is purged, set up another hose and purge each secondary circuit individually. 90004 90002 90012 PUMPED PURGING 90013 90004 90114 90002 Figure 6 90004 90002 Some hydronics systems may not have access to pressurized cold water systems for purging.Other systems may need to be filled and purged with a premixed antifreeze solution. Both of these scenarios can be handled using a double port purging valve such as the one shown in Figure 6. 90004 90002 Double port purging valves combine two side port ball valves with a single inline ball valve. One side port allows fluid (water or antifreeze solution) into the system. The other lets air out of the system. A typical circuit using a double port purging valve is shown in Figure 7. 90004 90002 A submersible pump is used to force fluid in and around the circuit.Air exits the upstream side port of the purge valve. Eventually, a stream of fluid flows from the exit port and is carried back to the fluid reservoir. It is important to keep the end of the return hose under the fluid level in the reservoir to avoid creating bubbles that get pulled back into the purging pump. The purging pump is operated until the return stream is free of bubbles for several seconds. At that point, the outlet port of the purge valve is closed. This allows the purge pump to increase system pressure.Fluid is forced into the expansion tank until the system pressure reaches the maximum (no flow) pressure of the purge pump. The final step is to close the inlet port on the purge valve and turn off the purge pump. If additional pressure is needed in the circuit, more fluid can be added using a hand pump. 90004 90123 90002 Figure 7 90004 90002 With modern hardware and methods it is possible to efficiently purge air from just about any hydronic system and keep that system essentially air free over its full service life.90004 90002 90026 John Siegenthaler, P.E., is a mechanical engineering graduate of Rensselaer Polytechnic Institute and a licensed professional engineer. He has over 34 years experience in designing modern hydronic heating systems. Siegenthaler’s latest book, Heating with Renewable Energy, was released recently (see www.hydronicpros.com for more information). 90029 90004.