Expansion tank for water: choice of device, installation and connection

The organization of water supply in the private house has achieved full automation. The minimum set of equipment and competent use of the laws of physics - and suburban housing has in no way inferior to the comfort of a city apartment.

Even an ordinary expansion tank for the water supply is improved in such a way as to minimize user involvement in the water supply.

Features closed expansion vessels

Hydraulic tank (pressure accumulator or expansion tank) - a hermetic metal container which serves to maintain a stable pressure in the water and create a different volume of water reserves.

At first glance, the choice and installation of the device should not cause difficulties - in any online store, you can see many models, which are only slightly different in shape and size, but did not significantly differ in their functionality. But it is not so. In the arrangement of the expansion tank and the principle of its work has a lot of nuances.

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Accumulator - a mandatory component of an automated independent water supply system that performs a number of important functions

As with conventional storage tank it serves to form a water reserve, but it is not his main task

Turning on the hydraulic tank in the water circuit to protect the system from water hammer

Hydraulic tank in tandem with the pressure switch provides the ability to automate the water intake equipment and prolong its service life

Accumulators are supplied in small volume format pumping stations assembled in the factory

Hydraulic tank in the circuit with a downhole pump has a greater volume, it is installed separately from the water intake unit

The complex water systems in which the pressure can fall from either branching or by long-haul routes, hydraulic tanks are used as additional redundant points

If the water intake is likely to work with "dry running", the accumulator works in tandem with the automation unit, not with the pressure switch

Accumulator in the water system

The capacity to create a water reserve

Means of protection against surge

Automation of work equipment

Accumulator in a pump station

Hydraulic tank paired with a submersible pump

As additional equipment

Accumulator and automation unit

Design features expansion tanks

Different models of expansion tanks may have restrictions on the method of use - some are only designed to work with the process water, the other can be used for drinking water.

By design, hydraulic accumulators are distinguished:

• tanks with replaceable bulb;
• vessel with a fixed membrane;
• The hydraulic tanks without a membrane.

On one side of the tank with a removable membrane (at the tank with bottom connection - at the bottom) there is a special flange with thread, to which is attached a pear. It has a nipple for pumping or venting of air and gas from the back. It is designed for connection to a conventional automobile pumps.

In a tank with a removable pear water is pumped into the membrane without coming into contact with the metal surface. Replacement of the membrane occurs by loosening the flange which hold the bolts. In large tanks to stabilize the filling, the rear wall of the membrane is further attached to the nipple.

Lifetime removable pears depends on the air pressure setting in the gas accumulator compartment. Sometimes, to create a larger supply of water, the user reduces the amount of air increases and the amount of water in the pear. This leads to touch the membrane to the wall of the tank, and causes rapid wear

The inner space of the tank with a fixed membrane divides it into two compartments. In one is gas (air) to another water enters. The inner surface of the tank is covered with a moisture-resistant paint.

Most often, tanks with fixed membrane used for heating systems. Since the membrane - is an element that breaks down more quickly, and the service life of such a tank smaller than the device with a detachable pear

There are also hydraulic tanks without a membrane. They compartments for air and water does not separate. The principle of operation is also based on the mutual pressure of water and air, but such an open interaction occurs mixing of the two substances. The advantage of such devices - the absence of a membrane or a pear, which is the weakest link in the usual accumulators.

Externally, expansion tanks can be divided only on the horizontal and vertical models, but their operating parameters can be very different

Diffusion of water and air forces to maintain tanks frequently. About once every season has to pump up the air, which is gradually mixed with water. Significant reduction in air volume even under normal pressure in the tank to become the cause of frequent switching on the pump.

Accumulators in the water supply system reduces the risk of water hammer, protect the pump from too frequent switching, allow to generate and maintain a supply of water pressure circuit

The operating principle of the hydraulic tank

Closed hydraulic tanks for water working on this scheme: the pump delivers the water into the bulb, gradually filling its membrane increases and compression of air takes place, which is between the blower and the metal housing. The more water flows into the bulb, the more it puts pressure on the air, and he, in turn, tends to push it out of the container. As a result, the pressure rises in the container, it turns off the pump.

A time when there is water in the system flow, compressed air support pressure. He pushes water into electricity. When its amount in the membrane is reduced so that the pressure is lowered until the lower limit switch is activated again including pump.

The hydraulic reservoir is a constant interaction between the water and the gas separated by a rubber membrane. The volume of liquid in the device controlled by the amount of gas (its pressure) (+)

Classification by application

Do not confuse the tanks for water supply and heating system, so when choosing a need to know their purpose. For clear identification of paint manufacturers accumulators for heating in the red, for water - blue. But some do not adhere to such a marking, so the hallmark of devices may provide the following data:

• water for maximum use temperature of the accumulator will be up to 70 ° C, permissible pressure can reach 10 bars;
• devices for heating, can withstand temperatures up to +120 ° C, the operating pressure of the expansion tank is often not higher than 1.5 bar.

All of the most important parameters are listed on the decorative cap (plate), which closes the nipple.

A device for the heating system is an additional tank, allowing the coolant to expand freely when heated. Without it, the system is doomed to destruction

The list of functions performed by hydraulic tank in the system IV of (cold water), a much broader:

• Maintaining a smooth and constant pressure in the water. Due to the air pressure, while the pressure is maintained even when the pump is switched off until it falls to a prescribed minimum and the work again turns on the pump. Thus the pressure in the system is maintained even when using multiple plumbing fixtures.
• Protection against wear of the pump equipment. Supplies of water contained in the tank, allowing for some time to use water, not including the pump. This reduces the number of pump actuations per unit time and prolongs its operation.
• Protection against water hammer. The sharp jump in pressure in the water when the pump is turned on can reach more than 10 atmospheres, which has a negative impact on all elements of the system. Diaphragm tank takes the hit, equalizing the pressure.
• Creating water reserves. When disconnecting the electricity supply system at least not for long, but, nevertheless, some more time will be given to water.

Strapping cylinder using expansion tanks, which can withstand high temperatures.

Materials for the manufacture of tanks

The membrane expansion tank is made of different materials, which can withstand operation at a different temperature range. The accumulator is used:

• Natural rubber tires - NATURAL. The material may be in contact with drinking water, is used for storage of cold water. May eventually start to leak. It withstands temperatures between -10 and 50 ° C above zero.
• Synthetic butyl rubber - BUTYL. The most versatile, waterproof, used for water supply stations, suitable for drinking water. Operating temperature can range from -10 to 100 ° C.
• Synthetic rubber of ethylene-propylene - EPDM. More permeable than the previous one, may come in contact with drinking water. allowable temperature range - from -10 to 100 ° C.
• Rubber SBR only applicable for industrial water. Operating temperature is the same as that of the earlier marks.

For the organization of cold water tanks must be chosen with pear, made of food-grade rubber with improved elastic properties, which allow better quenching hydraulic shocks and to maintain a stable the water pressure in the system.

tank housing often made from stainless steel, a corrosion-resistant coated externally lacquered. The sale is also possible to meet the capacity of stainless steel, very strong, but expensive.

How to select and calculate the volume of the tank

In commercially available tanks capacity from 24 to 1000 liters. Which to choose, prompt payments, the result of which should be rounded upwards. Choosing a tank with a removable membrane, it should be remembered that the amount of water is 30% of the total volume of the container, that is, in a 100-liter tank of water supply will be approximately 30 liters.

Table shows the relationship in the gas compartment pressure air accumulator parameters with switch settings and the size indicators tank (+)

Especially small tanks is that they often do not have a valve to bleed the air from the blower. This may cause discomfort during the operation. Large containers have such a valve, and in addition to building more water storage, better able to cope with the maintenance of stable pressure in the system.

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For autonomous system with one or two draw-off points usually buy a small tank with a capacity of 10 liters

Accumulators of 14 - 35 l work well in tandem with surface pumps are not too sensitive to frequent activation starts / disconnections

Submersible pumps are more sensitive to the often produced launches from blackouts because in their design over the rotating parts

To minimize starts submersible pump in the water circuit tanks include a volume of 50 liters or more. The same is done in areas with power outages

The specificity of the selection by volume

Surface Tank with pump

Accumulators with downhole pumps

Hydraulic tank for submersible pumps

Calculation of the total volume of the fluid container for water gated calculated by the following formula:

Vt = K * Amax * ((1 + Pmax) * (1 + Pmin)) / (Pmax-Pmin) * (1 + Pvozd).

Where:

• Vt - the total volume of the fluid container;
• Amax - maximum possible consumption of water per minute, per liter;
• K - coefficient (cm. Table), which depends on the power of the pump.;
• Pmax - switch settings when disconnecting equipment, a bar;
• Pmin - switch settings when starting the equipment, a bar;
• Pvozd. - pressure in the hydraulic reservoir (in its gaseous cavity) bar.

The coefficient K can be determined from the following table:

Table K coefficient, which depends on the pump power, to calculate the total fluid container closed type water

Some manufacturers also consider the amount of the hydraulic tank on the other:

JEELEX company, which manufactures an extensive line of equipment for water supply and heating, offers yet another formula to express definitions hydraulic tank volume

Horizontal or vertical tank?

The choice between vertical and horizontal tank lies in the peculiarities of the room. If the room is small or the amount of an impressive capacity, then that does not take up much space, install a vertical tank.

Horizontal tank has a lower capacity, can be suspended on the wall and serve as a support surface for the installation of the pump. For mounting special fasteners provided. Large tanks are manufactured in vertical design and are mounted on the legs.

Summarizing all the above, it may be noted that the choice of accumulator will perform between these distinctive features:

• operating pressure;
• the country of manufacture;
• greater or lesser volume;
• removable or no rubber membrane;
• membrane for technical or drinking water;
• body material - stainless or enameled steel.

That there were no problems with the replacement of components, it is best to choose the most running models of devices in the future. Rubber pear for them there is always freely available, if needed urgent replacement, do not have to wait long for delivery.

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Accumulators produced in horizontal and vertical versions. Tanks volume to 10 l vertically oriented, to deprived mounts building structures and supports

Horizontally oriented accumulators average capacity. Usually this unit volume from 14 l to 50 l

Membrane tanks for water, can accommodate more than 50 l, produced in a vertical embodiment as the most compact to install large tanks

Vertical membrane tanks installed separately from the pump equipment fitted with sturdy and stable support legs capable to keep 50 to 750 kg

Vertical tank is unsupported

Accumulators average capacity

Membrane tanks with legs

Features vertical models

Wiring Diagrams Hydraulic tank

For a system of hot water installation of the expansion tank is carried on a circulation line portion, the suction line of the pump is closer to the water heater. The tank is equipped with:

• pressure gauge, safety valve, air vent - Safety group;
• a shutoff valve with a device that prevents accidental overlapping.

In the water system, where there is water heating equipment, the device takes over the functions of the expansion tank.

Scheme installation system GW 1 - hydraulic reservoir; 2 - a safety valve; 3 - pumping equipment; 4 - filter element; 5 - check valve; 6 - stopcock (+)

The system XB important rule when installing accumulator - installation at the beginning of the binding, close to the pump. The wiring diagram are always present:

• reverse and stop valve;
• security group.

Wiring diagrams can be very different. Connection of the hydraulic reservoir normalizes the equipment, reducing the number of pump starts per time unit and this prolonging its life.

Scheme It.V. mounting system with the well 1 - tank; 2 - check valve; 3 - the shut-off valve; 4 - switch for pressure control; 5 - pumping equipment control device; 6 - Security group

In Scheme boosting pump station with one of the pumps operates continuously. Such a system is established for homes or buildings with high water consumption. Hydraulic tank here serves to neutralize pressure peaks and the water storage capacity is set as large as possible volume.

As for installation of the expansion tank

Before starting work, check the accumulator for damage. The installation device is carried out in the soundproofed room temperature at zero. To have access to the tap for draining, valving and m. N., A distance from the tank to the ceiling and walls leave not less than 0.6 m.

The room also needs to provide for the tank filling and draining. Fasteners and mounting location must withstand a 100% occupancy capacity.

For expansion tanks up to 30 liter volume using wall mount, large capacity is mounted on legs

Gidroakkumulyatr be subjected to mechanical load and statistical undesirably expose the pipe and it aggregates. The tank is screwed to the floor, using rubber gaskets. On entering the tank is mounted a check valve for drain valve.

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Step 1: To connect the accumulator to the water system will require pressure switches, plastic pipe, amerikanaka 1 ", adapter and collet sleeve, fum-tape

Step 2: To ensure tightness at the node and the possibility to disassemble the equipment without damage to the sealing-tape threading fum

Step 3: To simplify the assembly / disassembly and the possibility of easily disassembled for repair to put an American pressure switch

Step 4: Connect a pressure switch, trying to place it at a comfortable angle for further exploitation and tracking parameters

Step 5: In spite of the fact that the manometer connection node is a relay gasket, the threaded connection at that location further pass the sealing tape

Step 6: knee from welded pipes of PVC for convenience and to simplify the connection line conveying the water to the consumers

Step 7: By located at the outlet of the pressure switch connect pipe welded pipes of PVC knee

Step 8: Using the sleeve for polyethylene pipes, equipped with a collet clamp connectable tap line from pump to tank

Hydraulic tank and devices to connect

Thread seal on the flange of the fluid container

Installing before American pressure switch

Connecting to the circuit pressure switch

Connecting the pressure gauge

Welding pipe for discharging the knee

Fixation knee for water

Fastening of the pipe from the pump to the relay

The above steps required for the binding apparatus accumulator that is produced at the surface. For further steps need to move to the caisson.

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Step 9: Sphere with strapping attached thereto plunges into a concrete caisson. If the tank is located on the surface, at this stage there is no need

Step 10: Putting it out of plastic pipes and fittings for water supply station in the caisson to take stock of pipes to the house

Step 11: For connecting electrical remove the lid from the pressure switch housing, using the flat screwdriver

Step 12: In the relay's opening holes we start the bare wires, fasten them to the terminals of a Phillips screwdriver

Immersion system portion in the caisson

Assembling portion aqueduct in the caisson

Removing the cover for electrical connection

Fixing the pump power cable

After the final assembly of the system is to carry out routine tests and run the loop supply.

Features accumulator adjustment

Expansion tanks for water supply are commercially available with standard manufacturer settings - often pressure in the air compartment is already set at a value of 1.5 bar. Permissible pressure is always indicated on the label and the manufacturer does not recommend that deviate from predetermined parameters, especially in the direction of its increase.

Before carrying out the adjustment, the system is disconnected from the mains and close the shut-off valves. Membrane tank is completely emptied by pouring water - fine pressure indicator can only be measured with an empty compartment for the water.

Further relieve pressure indicators by using an accurate pressure gauge. To do this, remove the spool cap and decorative tray unit. If the pressure is not correct, then it is brought into line, pumping or pitting excess air.

Given that the manufacturer against deviations from the recommended pressure indicators, you must still at the design stage to select the right equipment, the parameters of which will not conflict between yourself

When adjusting the pressure in the gas tank compartment producer fills it with an inert gas such as dry nitrogen. This prevents corrosion of the inner surface. Therefore, users are also recommended to use technical nitrogen to increase pressure.

Setting the tank pressure in the water system

The pressure in a closed type tank always set somewhat lower (10%) than the pressure level when the pump starts. By adjusting the pressure in the device can adjust the water pressure. Will be smaller than the gas pressure in the hydraulic reservoir (but not less than 1 bar), the more he will seat himself in the water.

The pressure in this case will be uneven - with strong filled the tank and all the weaker in its devastation. To ensure a strong and smooth water flow set pressure in the chamber with air or gas in the range of 1.5 bar.

The water pressure in the water is set by the relay. When setting up the pressure in the expansion chamber is necessary to consider these values

Adjusting the hydraulic tank in the heater piping

Expansion tank which is used for hot water supply, initially should not contain water. The pressure in the apparatus is set on the record, which is 0.2 greater than the upper threshold pump shutdown. For example, if the relay is configured to switch off the equipment at rates of pressure of 4 bar, the pressure in the gas compartment of the expansion tank must be set at a value of 4.2 bar.

Mounted to the trim heater, the tank is not used to maintain the pressure. It is designed to compensate for expansion when the heating of the water takes place. If you set the pressure therein to a lower value in the tank will always be water.

Terms of Service hydrotank

Routine inspection of the expansion tank is to test the pressure in the gas compartment. It is also necessary to inspect the valves, stop valves, venting, test the pressure gauge. To ensure the integrity of the tank by inspection.

During maintenance, it is necessary to measure the pressure in the hydraulic tank and adjust it, if necessary

Despite the simplicity of the device, expansion tanks for water supply is still not permanent and can break. Specific reasons - membrane rupture or loss of air through the nipple. Signs of damage can be determined by frequent triggering of the pump, the appearance of noise in the plumbing system. Understanding the principle of operation of the accumulator - it is the first step towards proper maintenance and fault rectification.

Characteristics and installing hydraulic tank open

open-type device is used less and less, because it requires the constant intervention of the user in his work. Outdoor expansion tank - a leaky container which serves to form in the water pressure, water storage, and also serves as an expansion chamber.

To the tank is connected: drain valve, for recirculation pipes and supply pipe, control and overflow tube

Tank mounted above the uppermost point of the plumbing, for example, the loft, water flows by gravity into the system. Each meter on which the device rises, increasing the pressure in the water at 0.1 atmospheres. To automate the process of providing water tank equipped with float switch and set the auto switch to be turned on and off the pump.

Capacity mounted in frost-proof room, covered with a lid from the dust and debris wrapped wall with mineral wool or other insulation

This way of organizing water supply require regular user control, otherwise the water at low temperatures may freeze (if the room is not heated). The liquid will evaporate, so you have to constantly refill it.

In addition, such a container bulky and not aesthetically pleasing, a must-have in the house attic space for her. But the main disadvantage of the device - the tank is not designed to operate under high water pressure in the system.

Useful videos on the topic

All of the expansion tanks - classification, purpose, adjustment problems and symptoms:

Improper operation of the pumping station is often associated with faults accumulator:

Nuances selection hydraulic reservoir for water:

At the stage of water system planning and development need to consider all the important points of principle and figure out all the options. If there is no confidence in the infallibility of their calculations and the correct choice of the hydraulic tank for water supply, it is best to contact the experts.

Many firms that are engaged in the implementation of professional equipment, provide advice or carry out calculations for free. This will help to avoid mistakes and unnecessary spending.