Potable water tanks with PZH certificate

• Drinking water tanks – file with size table
• The diameter ranges from 3.1 m to 21.7 m
• The height of the tank wall is from 2.4 m to 13.2 m
• It is possible to build a tank of a higher height

• PN-EN 1990:2004/AC:2010 „Eurocode. Basics of structural design.
• PN-EN 1991-1-1:2004/AC:2009 „Eurocode 1. Impacts on structures. Part 1-1. General impacts. Volumetric weight, self-weight, operational loads in buildings.
• PN-EN 1991-1-3:2005/AC:2009 „Eurocode 1. Impacts on structures. Part 1-3. General impacts. „Snow load.”
• PN-EN 1991-1-4:2005 „Eurocode 1. Impact on structures. Part 1-4: General impacts. Wind Impacts.
• PN-EN 1993-1-1:2006/AC:2009 „Eurocode 3: Design of steel structures. Part 1-1. General rules and rules for buildings.
• PN-EN 1993-1-3:2008/AC:2009 „Eurocode 3. Design of steel structures. Part 1-2: General rules. Supplementary rules for structures made of cold-formed sections and sheets.
• PN-EN 1993-4-2:2009 „Eurocode 3. Design of steel structures. Part 4-2: Tanks.”
• PN-EN 1993-1-6:2009 „Eurocode 3. Design of steel structures. Part 1-6: Strength and stability of shell structures.
• PN-EN 1090-2+A1:2012 „Execution of steel and aluminum structures. Part 2: Technical requirements for steel structures.
• PN-EN ISO 13788:2013-05 „Thermal-humidity properties of building components and building elements. The internal surface temperature necessary to avoid critical surface humidity and interlayer condensation. Calculation methods.”
• PN-EN 12831:2006 „Heating installations in buildings. Method for calculating the design thermal load.
• PN-EN ISO 12944-2:2018-02 „Paints and varnishes. Corrosion protection of steel structures using protective painting systems. Part 2: Classification of environments.”
• PN-EN ISO 12944-5:2020-03 „Paints and varnishes. Corrosion protection of steel structures using protective painting systems. Part 5: Protective paint systems.
• PN-EN ISO 14713:2000 „Protection against corrosion of steel and cast iron structures. Zinc and aluminum coatings. Guidelines.”

Foundation slab

MILTOM system tanks intended for storing drinking water are placed on a reinforced concrete foundation slab. The reinforced concrete foundation slab is designed individually for a specific location, based on the soil and water conditions received from the Investor. It is made of hydrotechnical concrete, min. class B25 (C20/25) W8 F100, frost-resistant and waterproof. Reinforcement of the tank bottom plate with top and bottom steel class A-IIIN BSt500. Reinforcement cover from the bottom and sides 5 cm, from the top 7 cm. The bottom slab is made on a B10 concrete base, at least 10 cm thick. The diameter of the foundation slab is made in the form of a circle or polygon with a diameter of approximately 0.9 m larger than the internal diameter of the tank.

For calculations of the strength of the foundation, only the weight of the water collected in the tank can be taken into account. The weight of the structure and piping is up to 2% (for tanks up to 300 m3) to 5% of the weight of water. Therefore, it can be omitted by using other safety factors resulting from, for example, the possibility of tank overfilling. The decision on the design weight of the tank and the size of the safety factors rests with the designer.

Technologies used

The drinking water tanks we produce are made using two technologies. With an internal membrane made of EPDM or with joint sealing of sheet metal joints, type Sabatack 750 or 780.

The tank is sealed with an EPDM membrane

certified by the National Institute of Hygiene, is placed on a properly prepared and maintained foundation slab. The membrane is a polymer geosynthetic barrier manufactured from vulcanized EPDM. Calendered in two layers, without reinforcement. This gives unique properties, especially in terms of flexibility and elasticity (300% extensibility). The membrane is separated from the tank foundation with a polypropylene geotextile with a grammage of 300g/m2, which protects it against mechanical damage during installation and operation.

Sabatack sealed tank structures

are placed in a previously prepared technological groove 45 mm wide and 50 mm deep, located at the height of the circumference of the tank shell structure. In order to permanently and tightly connect the tank walls with the bottom plate, the tank groove is filled with self-leveling mortar from SABA.After the resin has hardened, the groove is additionally secured with a permanently elastic mass called Ecoseal Bio HM, which is approved for contact with drinking water. The bottom of the tank is additionally protected with Aquafin-1K M-PLUS mortar.

Tanks with sealing and protection of all connections of the tank shell elements with Sabatack 750, 780 mass are painted on the inside with Faproxyd 620 powder paint in signal blue (RAL5005) from WODROL.

Tank walls

In both technologies, the tank walls are made of galvanized steel of the S350GD + Z275 grade or acid-resistant AISI 304 (1.4304) or AISI 316L (1.4401) steel with sheet dimensions of 1.25 m x 2.5 m. The thickness of the jacket depends on the size of the tank and the required standards. . Individual sheets are screwed together vertically and horizontally using M12 screws, class 8.8. The walls of the tank are reinforced horizontally with rings made of 2.0 – 4.0 mm thick sheets. The tank is attached to a concrete foundation using galvanized L70x50x5 angles made of S235 steel, brackets and expansion anchors.

Additional options

At the customer’s request, it is possible to powder-coat the sheet metal surfaces or cover the installation jacket with a trapezoidal sheet in a selected RAL color from the available „Pruszyński” color palette.

Painting the tank shell or the façade made of trapezoidal sheet metal constitutes an additional layer of protection against the effects of the external environment, significantly prolonging the proper operation of the tank and its failure-free operation, and also provides an additional visual and aesthetic effect.

Tank roof

Depending on the investor’s needs, we cover drinking water tanks with a dome made of a polyester-glass composite or with a conical roof. All the roofs we offer are self-supporting structures, which means there is no contact of water with the structure elements, significantly extending their service life.

The use of a roof covering in the form of a „KS” dome (self-supporting dome).

This cover consists of spherical elements (i.e. the shell of the element is a segment of a sphere) with side flat flanges lying on the spherical surface of the sight glass, the sight glass cover and the drip cap (without gutter) around the entire circumference of the tank. The spherical elements are connected together using an overlapping screw connection. Each lap screw connection of the flanges of the covering elements is sealed with two rows of EPDM gaskets with a cross-section of 10×15 [mm]. The distance between the axes of the screws and anchors securing the cover elements to the steel structure of the tank is not greater than 330 [mm]. Between the flange of the outermost element and the steel structure there is a drip cap made of polyester-glass laminate. Between the drip cap and the tank wall and between the drip cap and the covering elements, there are two rows of EPDM gaskets with a cross-section of 10×15 [mm]. Spherical elements made of polyester-glass laminate insulated with 60 [mm] thick PU foam – the foam is not placed in the places of screw connections.

Conical tank roof structure (truncated cone)

it is pivotally supported on the walls of the tank. The angle of the roof is approximately 15º. Roof load-bearing beams made of cold-bent galvanized profiles. Pruszyński sheets 2xC150x48x2.0 made of S350GD steel are radially evenly spaced. Roof load-bearing beams fastened in the roof crown with a round keystone with a diameter of d = 856 mm and an equivalent design I-shaped cross-section Hśr x Bpg x Bpd = 172x344x158 welded from steel sheets of thickness. 8 mm made of S235 steel. Connection of load-bearing beams with the keystone using M12-class 8 screws. Styrodur-3000CS insulation with a thickness of 100 mm was placed between the load-bearing beams. The roof is covered with flat sheet metal with a thickness of 1.0 to 3.0 mm. All roof connections in the tank are protected from the inside with Sabatack. The shape of the roof structure ensures free drainage of rain and snow from the roof surface to each side of the tank.

Regardless of the shape and type, each drinking water tank roof is equipped with:

Supply ventilation chimneys (air intakes) enabling free air flow into the space under the roof covering (protecting the roof covering against negative pressure caused by the variable level of liquid in the tank); gravitational air inflow is assumed.
Pipe stubs permanently laminated into the roof covering to connect the ventilation system for collecting polluted air from the space under the roof covering. The number, size and location of the spigots are determined by the ventilation designer. Designed solutions must be consulted with the roof covering manufacturer.
Manhole – pronounced inside 800 x 800 [mm] The hatch is equipped with hinges and tilt limiters for an opening angle of up to 95°. The fittings are made of A4 steel. The location of the manhole, spigots and ventilation chimneys is agreed at the stage of detailed technical arrangements for the covering.
A filter protecting against the entry of insects, rodents, birds and dust, made of stainless steel mesh with a mesh size of 0.5 mm, is placed in the ventilation chimney, which also prevents the entry of atmospheric pollutants.
Each tank is equipped with external thermal insulation made of ProRox SL 960 PL mineral wool, 10 cm thick, additionally protected with trapezoidal sheet metal T18 x 0.7 „Pruszyński” painted in any color from the RAL color palette. This location of the insulation ensures long-term preservation of thermal properties and no degradation of the material under the influence of moisture.
The tank equipment also includes: a supply (pressure) pipeline, a suction pipeline, an overflow pipeline and a discharge pipeline, made of acid-resistant steel or polyethylene with a diameter adapted to the requirements of the Ordering Party.

All the materials we use ensure that the investor is provided with the highest quality product that meets the strict requirements of norms and required standards.

The full modularity of the structure allows for quick assembly, as well as the possibility of any modifications to increase the required tank capacity, if necessary. Our tanks are equipped with all the necessary connections and devices required for efficient operation in water treatment plants and water supply installations.High quality of workmanship allows you to obtain a long-term warranty, ensuring many years of trouble-free use of the tank.