Tanks construction

Fire protection tanks- construction

Tanks have cylinder shape settled in vertical position. The fire protection tanks’ coat is made of an illuminating hot- dip galvanised sheets. We choose the steel thickness according to required and valid standards. Solid steel combination is guaranteed by the fire galvanised bolts. We strength the coat of the tanks with a wind angle brackets

The roof of the tanks self-supporting or supported by the vertical bearing elements according to the required snow load standard. We make the roof out of the sandwich panel or two layers of the trapezoidal galvanized steel or in the color from the RAL palette. Core but we make from the foam polysterene with 60 mm thickness.

Vertical bearing elements of the roof installed above the water level. The roof with the 0,5% pitch let for the free rainwater outflow. We install the tank to the foundation slab with the anchors and anchor bolts. According to the requirements of the local seismic zones.

The tank construction and the technological solutions are designed by own design- research unit according to the mentioned below norms, regulations, recommendations, guidelines and standards:
  1. Steel constructions- cylindrical vertical liquid tanks- Design and execution
  2. Steel Constructions- Static Calculations and Design
  3. Loads in Static calculations- Snow load
  4. Loads in Static calculations- Wind load
  5. Permanent fire- fighting device- Sprinkler systems- Design, installation and maintenance
  6. Decree of the Internal Affairs and Administration Minister from 21st April 2006 about fire protection of the buildings, another construction facilities and areas (Journal of Laws No. 80, item 563 of 11th May 2006)
  7. Decree of the Internal Affairs and Administration Minister from 16th June 2003 about fire protection water supply and fire roads Journal of the Laws No. 121 item 1139
  8. DIN-18800 Stahlbauten-Stabilitäsfälle, Schalenbeulen.
  9. ANSI/AWWA-D103 Factory-Coated Bolted Stell Tanks For Water Storage.
  10. Approval Standard for Ground Supported Flat Bottom Steel Tanks for Fire Pump Suction FM Global.


Optionally, the tank can be sealed from the inside with a PVC film welded on site or a prefabricated EPDM membrane.

1. PVC film

  • thickness min. 1.5mm thick,
  • vulcanized on site,
  • guaranteed service life of 35 years,
  • high resistance to mechanical damage,
  • guarantee of full tightness already at the first test,
  • 24 h replacement time in case of leakage

2. EPDM membrane

  • 0,75mm-1,00mm,
  • delivered to the site in the form of ready-to-assemble bag,
  • guaranteed service life of 30 years,
  • very good properties regarding shrinkage and expansion up to 300% elongation,
  • time of replacement in case of leakage 14 days

These solutions ensure that the stored water does not come into contact with the thermal insulation and the steel walls of the tank, thus preventing corrosion centres

As protection against penetration of the membrane, a geotextile with a density of min. 150g/m2.

Thermal isolation

The internal isolation of the roof and walls of the tank is provided as standard by polystyrene XPS panels with a thickness of min. XPS polystyrene boards of min. 60mm thickness and varied hardness depending on the assumed water column pressure. Polystyrene boards are fastened with screws between the membrane and the construction sheet.

External isolation typical for tanks covered with trapezoidal or corrugated sheet metal. Tank walls insulated with 100mm mineral wool and covered with galvanised trapezoidal sheet metal or in a RAL colour.

  • Antifreeze protection
  • Fire reservoirs are equipped as standard with a system of two or three independently operating heating batteries with thermostat ranging from 3kW to 6kW. Heating elements in a version for phase-to-phase connection.
  • The heaters are equipped with automatic thermostats with temperature control, maintaining water
    temperature in the tank at +5°C. In the event of heater failure, it is not necessary to drain the tank completely.
  • The heaters operate in a three-phase system. Protection degree of electrical connections and thermostat IP67. Power supply 400V.
  • For tanks of diameter 14.51 m, immersion heaters are used, installed in the tank shell 550 mm below the maximum water level in the tank. Heaters are located in close proximity to float valves or supply pipes. Mounting technology with the use of flanged passage with threaded orifice allows their free unscrewing for possible repair.
  • In case of tanks of diameter ? 15.27m, pendant-type immersion heaters are used, mounted below the water table on the ordinates according to the KAPEO design.
  • The selection of the type and power of the heating batteries depending on the tank model is presented in the heater power selection table available in the download section.


  • thermal insulation of walls and roof made of polystyrene boards 60mm thick,
  • foundation thermal transmittance coefficient U=1,
  • no water exchange.


1. Process lines:

The used technical solutions as well as the technology of the offered tanks allow us to adjust technological hoses in terms of: diameters, location or location of flange transitions. All connections inside the tank are galvanized. They can be routed both through the tank shell and the foundation plate.

Depending on the needs, the tank may be equipped with such hoses as:

  • suction line with antivibration plate for the pump set,
  • suction line with antivibration plate terminated with a double W 110 fireman'scoupling as a water intake point for the fire brigade,
  • test-return line,
  • relief pipe,
  • supply line with one or two maintenance-free float valves,
  • drain with butterfly valve,
  • an equalizing line as a connection between two tanks.
  • In case of flange crossings through the tank wall, their location is limited only by the horizontal joints of the shell plates. Proposal of line axis ordinates from the foundation surface: -suction line 1000mm, -test line 1300mm, -feed line 300mm, -drain 150mm. Pipes going through the tank shell should be protected with a heating cable. Please contact the Technical Department for confirmation of the line axis selection.

The location of pipes leading through the foundation slab from the tank shell to the edge of the flange should be as follows 300mm-feed line, test line, relief line, overflow line; min. 1100mm - suction line, drain line, equalization line.

It is RECOMMENDED to use steel pipes protected against corrosion. Due to the possibility of leakage, connecting materials other than steel, i.e. cast iron, PE or PVC should be done outside the foundation slab. The detail of the flange connection in the foundation slab should be made in accordance with the manufacturer's guidelines. Pipes led outside through the tank shell are terminated with a 400mm long stub pipe with a flange for further connection. Flanges according to PN 16.

If the stored water is to be used for external fire extinguishing, the tank is equipped with external connections for water intake by fire pumps or fire vehicles. These connections are equipped with sockets size 110 in accordance with PN-91/M-51038 standard and with sockets covers in accordance with PN-91/M-51024 standard. The tank used for the above mentioned purpose meets the requirements of PN-82/B-02857.

The pipelines are led through the tank foundation below the ground freezing zone, which allows avoiding the application of thermal isolation.

The scope of delivery of the fire tank manufacturer includes both process piping and necessary fittings, i.e. float valve on the supply pipe, shut-off damper on the discharge pipe and fireman's couplings on the suction pipe with shut-off damper.

A fire road with a hardened and suitably resistant surface should be led to the tank in accordance with the regulation of the Minister of Internal Affairs and Administration of January 15, 1999 on defining detailed requirements for fire water supply, technical, chemical, ecological or medical rescue and conditions to be met by fire roads (Journal of Laws No. 7, item 64).

2. An external cage ladder with a platform to enable access to the inspection hatch on the tank roof.

3. Working platform with guardrail.

4. Tank operating controller:

A water tank controller installed in an IP 65 enclosure, usually on the outside wall of the tank or pumping station building, is intended to provide continuous monitoring of the tank's performance and to alert of malfunctions or defects.

Water level monitoring

The monitoring system, by means of pendant probes installed inside the tank, controls the current water level conditions in a four-level system

The probes are factory configured as follows:

  • TRANSFER level: this is the highest (alarm) level, reaching this level by water indicates malfunction of float valves and in consequence may mean uncontrolled water overflow. Reaching this level by water is signalled by overflow diode lighting up in red colour
  • MAXIMUM level: this is the level of maximum filling of the tank, ensuring proper protection of the object. The monitoring system allows the heaters to operate. Decrease of this level indicates malfunction of the water system and is signalled by an alarm when the maximum diode turns red. If the water level drops below the maximum level, the automatic system switches off the operation of the heaters.
  • INDIRECT level: this is the level that indicates that the tank is 50% full. It serves as an auxiliary signal during repair or service works. It is possible to select a different indication of the water level. Reaching this level is signaled with an alarm by the red diode of the intermediate level lighting up.
  • MINIMUM level: This is the minimum filling level of the tank, signalling the start of emptying of the lower dead zone. The probe is located 50mm above the edge of the suction pipe anti-vibration plate and serves as a warning signal to prevent the pump sets from running dry. Reaching this level is signalled by the minimum red light.

All signals from the probes are collected via a relay in the control cabinet, i.e. the tank operating controller.

Control of the heating system

In order to protect the stored water against freezing, electric heaters are installed in the upper part of the tank, with a thermostat controlling their operation.

The heaters turn on when the water temperature falls below +5ºC and turn off at +6ºC.
If the temperature of the water in the tank falls below +3ºC, the system will report a failure by lighting the red low-temperature indicator light.

To prevent damage to the internal insulation of the tank, the control circuits will switch off the heaters if the water level falls below the MAXIMUM level.
If the contactor cuts off the voltage directed to individual heaters, the system will report a failure through the red lighting of the power light.

Tanks made in FM standard are equipped with a temperature measurement set with an alarm device.

Alarm state signalling

The following alarms are prepared for objects equipped with SAP installation:

  • tank collective technical alarm {terminals 9,10,11}.

Additionally, the tank controller can be equipped with individual signals:

  • overflow level alarm,
  • maximum level alarm,
  • low temperature alarm,
  • jokey pump alarm.

For facilities without SAP installation it is recommended to use an external optical and acoustic signalling device to signal a failure {terminals 12,13}.

Two-colour LEDs have been installed in the synoptic module to illustrate the operating status of the tank:

  • normal state green diode is on,
  • alarm: red LED is on.

water temperature control:

  • the temperature above 3oC green diode is on,
  • The temperature below 3oC red diode is on.

heater operation control:

heater in stand-by mode no illumination,
heater in operation mode green diode is lit,
ed diode G1 or G2 is lit.

Power supply

Controller is powered from 3x400V,N,PE,50Hz mains with YKY 5x6mm2 cable. It is recommended to supply the controller from an electrical switching station equipped with a second level of overvoltage protection.
The casing of the controller with dimensions of 380x300x120 meets the condition of IP 65.

The facade of the tank

As a standard, the tank external facade consists of factory-made, double-side galvanised steel plates of the tank shell. On request, the tank shell sheets and flashings can be electrostatically painted in a RAL colour. The paints used are resistant to weather conditions.

The tanks can be covered with trapezoidal sheet metal with T 18 or T 35 profile in a RAL colour. Metal sheets are mounted vertically.

Anti-corrosion protection

Steel elements of the structure as well as tank equipment are protected against corrosion with the hot-dip galvanizing method, which makes them resistant to weather conditions. At the customer's request, it is possible to paint the external metal sheets of the shell using the electrostatic method, thus creating, apart from the zinc layer, an additional protective layer.

The modern technology of tank sealing separates the stored water from the steel walls of the tank, protecting the tank shell against corrosion centres. The tank shell plates are connected by hot-dip galvanised bolts with a zinc layer of at least 50 µm.

Scope of the delivery

I. Design: construction, execution and as-built phase.

Upon client's request, KAPEO designers, upon receipt of geological research, prepare foundation slab design for the tank, as well as execution and as-built documentation with design of tank's structural solutions.

II. Foundation slab:

KAPEO Company has qualified construction personnel, therefore, if requested by the client, the scope of delivery may also include the construction of a concrete base for the tank.

III. Delivery-assembly-sealing:

The scope of delivery includes all structural elements of the tank
and equipment including unloading on site and assembly. After the installation of the structure, thermal isolatation and process piping, the tank is sealed with a PVC foil welded on site or with a prefabricated EPDM membrane.

Tank preparation time for tightness test:

  • 200m3 - 7 days,
  • 600m3-10 days,
  • 200m3-14 days,
  • Leak tightness testing: 48 hours.

At the same time as the tightness test, the Tank Operation Controller is checked for correct operation

As-built documentation

After the completion of all construction and installation works and the tightness test, the as-built documentation is handed over together with the necessary documents and certificates

If a tank is used to store water for fire-fighting purposes for external fire extinguishing, the tank is equipped with external connections for water intake by fire pumps or fire vehicles. These connections are equipped with sockets of size 110 in accordance with PN-91/M-51038 standard and with the covers of the sockets in accordance with PN-91/M-51024 standard. The tank used for the above mentioned purpose meets the requirements of PN-82/B-02857

Kapeo Group:


+48 58 685 41 81



+48 58 685 41 81


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