Construction and calculation of a water tower for household needs

Recommendation points

• When is it advisable to install your own water tower
• How to calculate a water tower
• Finding out your water consumption
• We calculate the installation height of the tank
• Calculate the pipe diameter
• We select a pump for tanks
• We select tanks
• We select a support system for tanks
• Pipes

Is it advisable to install an individual storage tank? How to build a water tower on your own site? What formulas should be used to calculate the pipe diameter and water flow rate? Which foundation to choose? Our article will tell you about all this..

In the previous article, we talked about the structures, types and functions of water towers (WB). When it comes to water supply for an entire district or village, the installation of such a serious structure is certainly justified. But will it be useful to a private trader?

When is it advisable to install your own water tower

1. When connected to the city water supply. The private sector with gardens and vegetable gardens is a stable and powerful consumer of water, therefore, during the peak season, there is often a drop in pressure in pipes.
2. In the presence of significant areas to be watered. The water supply will ensure timely watering and maintain the technology of growing plants.
3. When engaging in animal husbandry. This type of activity requires a constant flow of clean water. In the tank, the water will settle and be heated naturally.
4. With unstable water and power supply. You will be able to fill your own tower during the best pressure (tension), for example, at night. Installation of simple automation will ensure the operation of the water supply system in autonomous mode.
5. When using your own well. WB will save energy and resource of the pumping station due to the optimal operating mode.

Simple analysis shows that having your own water tower is not an odd whim, but in many cases an absolute must. Reduced dozens of times, it will become a guarantee of reliable operation of pumps and constant uninterrupted water supply of a particular farm or house.

How to calculate a water tower

It will not be about a full-fledged water tower, but about a gravitational hydraulic system based on it. The rule we know – “the bottom of the tank should be located above the highest consumption point” – says that it is enough to set the tank at a certain level, which is not difficult to calculate.

Note.The initial condition is the availability of a source – own well with an installed pumping station or connection to the city water supply.

Let’s say there are two consumers – a vegetable garden and a cowshed. The first is located 35, and the second 25 m from the source. At the same time, the drinking bowls in the barn are set at a level of 1 meter. Watering the garden is carried out from ground level. The branches of the pipeline have a minimum common section of the pipeline (that is, they diverge close to the tank).

Finding out your water consumption

The volume of the tank directly depends on this indicator. Here, rather than calculations, but observations take place. It is necessary to install a water meter at the pumping station (source) and empirically set the daily flow. Let’s say the average consumption is 5 cubic meters. m / day. The volume of the tank should be 20% larger, we take 6 cubic meters. m.

We calculate the installation height of the tank

To withstand pressure, not only the height difference is important, but also the distance between the consumer and the source. 1 m of vertical movement of water is equal to 15 m horizontally. That is, in order to effectively move the water by “gravity” 15 m horizontally, a drop of 1 m is required. In this case, not the length, but the cross-section of the pipe is calculated in total. The calculated maximum length of one branch of the pipeline is taken.

Estimated post height for the first branch (H_st1) will be equal to:

• H_st1 = 35/15 = 2.3 m

The second branch (barn) has a level difference to increase (drinkers) and this must be taken into account.

Estimated post height for the second branch (H_st2) will be equal to:

• H_st2 = 25/15 + 1 = 2.66 m

Despite the fact that the second consumer is closer, he needs a higher post due to the difference in levels. The total calculated value is the largest indicator, i.e. 2.66 m.Add 15% of the stock and take H_st = 3 m.

The calculation shows that under these conditions the bottom of the tank should be at the level of 3 m, while the initial pressure in the system (at the bottom of the tank) will be:

• Р = рхgхh, Where
• R – water density (1000 kg / cubic meters)
• g – acceleration (9.8 m / s²)
• h – height of the water column
• P = 1000 x 9.8 x 3 = 29400 Pa = 0.294 MPa = 0.3 bar

Calculate the pipe diameter

Things are a little more complicated here. The required diameter is calculated from the flow rate and water flow rate. According to Toricelli’s law:

• V² = 2gh, Where V Is the flow rate, and h – the height of the post is:
• V² = 2 x 9.8 x 3 = 58.8
• V = square root of 58.8 = 7.66 m / s

We calculate the cross section of a 50 mm pipe using the formula S = Pr²:

• S = 3.14 x 0.0252 = 0.0019625 sq. m

We calculate the water consumption (R) according to the formula R = SV:

• R = 0.0019625 x 7.66 = 0.015 cc m / s = 15 l / s = 900 l / min

If the water flow per hour is known in advance, then the pipe diameter can be calculated using the formula:

• D = 2 square root of S / P, where S = R / square root of 2gh

In our case, the water consumption of 900 l / min is quite acceptable – the entire stock can be dumped in 6-10 minutes. In this case, the pipe diameter of 50 mm should not decrease.

Attention! Each 90 ° elbow gives a pressure loss of 5-7%. Design the system with the minimum number of corners.

We select a pump for tanks

As a rule, pumping stations are installed in the caisson of the well. It is reasonable to build a water tower directly above the caisson. This will allow all the components to be combined in one place, which in turn will simplify repair and maintenance. We talked about how to choose a borehole pump in one of the previous articles. The volume of water supplied to an average pumping station ranges from 4 to 9 cubic meters. m / min, which fully meets the needs of the conventional economy. The cost of equipment (pump, filters, fittings) will be approximately 15,000 rubles.

We select tanks

Tanks for water can be any, but must meet the requirements of tightness and be suitable for drinking water:

1. The best solution is cubic tanks with a volume of 1 cubic meter. m in a metal frame. They are called “Eurocube”. They usually have overflow, bottom and side openings for combining several tanks into one system. Thanks to their cubic shape, they are stable and take up a minimum of space. The frame allows them to be stacked on top of each other, which will increase the pillar. The cost of one new Eurocube is 8000 rubles, used – 4500 rubles. You will need 6 such cubes. – 48,000 and 27,000 rubles. respectively.
2. Solid homemade tank. It can be fabricated on site from sheet metal with stiffening ribs. This option may be unacceptable due to the deterioration of the properties of water during metal oxidation. Or you need to use higher grades of steel.
3. Associated barrels. Conventional metal drums of 200-240 liters can be an option for a modest budget. They also allow multi-storey layout and are inexpensive – 500 rubles / piece. (new). For 6 tons, 12 pieces are needed. total cost of 6000 rubles.

We select a support system for tanks

In any of the above-described cases of tank selection, we will need a 2×2 m site at a height of 3 m.The design mass of water at a maximum load is 6 tons. To hold such a mass, a foundation structure is required and there are two acceptable options.

Steel frame

Made of metal pipes. It consists of a foundation, struts, diagonal rods, platform plane material and, if possible, a visor. Racks made of pipes with a diameter of at least 75 mm are concreted with a step of 500 mm along the entire plane of the site. Spatial rigidity is created by diagonal rods (1 inch pipe, strip, reinforcement, etc.). The platform should be welded from a metal corner 45×45 mm or more. Leave a margin of 250-400 mm from the edge of the platform to the tank wall for possible insulation.

Walls (box)

Around the caisson, a strip foundation of about 2.5×2.5 m is arranged, into which pipes of 75 mm are concreted at the corners. Then the walls are laid out of cinder block or brick (1 brick thick). Stone pillars are laid out at the corners. As floor beams, use a channel of 85–100 mm with a pitch of 500–600 mm. Subsequently, the structure can be equipped for auxiliary needs.

Pipes

As can be seen from the conditions of the problem, the total length of the main line is 25 + 35 = 60 m. 20% for expenses, in total we take 75 m. The price of a polyethylene pipe is approximately 60 rubles / sq. m. Total 4500 rubles. per pipe + 500 rubles. for fittings = 5000 rubles.

When equipping a water tower for year-round use, remember about insulation. Even if it is empty in winter, some layer of insulation will save the tanks (unless they are steel) from temperature deformations.

In the next article we will tell you how to equip the hydraulic system at home and how to create a combined water tower for home and household.