The parts of MKD system are used for construction of a flue gas extraction system (chimney) resistant to the destructive impact of flue gas emitted by modern energy-saving appliances for such fuels as furnace oil or gas. A chimney made from the MKD system elements is an independent structure and it does not require applying any conventional ceramic materials.

The inside (fumes) conduit is made of acid-resistant steel of 1.4404 type that provides long-term acid-resistance in the environment resulting from extraction of fumes of a certain chemical composition. The outer jacket is made of stainless steel of 1.4301 type which provides long-lasting resistance to atmospheric conditions.

The use of the system consists in selection of appropriate parameters of the new chimney, its diameter which depends on the new heating appliance, and height that is usually based upon the regulations pertaining to the natural environment protection or upon the architectural elements located in the vicinity of the chimney to be designed. The diagrams presented in further pages of the catalog help to select the appropriate diameter of the chimney.

There are three possible variants of the construction of the fumes extraction system:

  1. Installation of appropriately selected parts (some of which are installed inside the building) with a suitable outlet.
  2. Installation of the fumes extraction system on the outer side of the wall of the building where the outer wall is used as the load-bearing structure, and the end part of the chimney is led above the roof of the building.
  3. Installation of the fumes extraction system on a separate load-bearing structure made of steel.

The temperature of the fumes from the heating units to be connected to the fumes extraction systems made of MKD system should not exceed 4000C. The composition of the fumes shall not be combustible and it shall not contain explosive components.

The construction of the flue-gas conduit should be made by trained personnel and it should follow the current construction regulations, investor"s recommendations and the recommendations of the manufacturer of the system.

The elements of the MKD system are ready to use, and they may be installed in any atmospheric conditions.

The flue-gas conduit should be selected so to – apart from the aforementioned conditions – provide the flue gas temperature higher than the dew-point for the given boiler along the entire length of the chimney together with the outlet. This condition does not pertain to condensation boilers in case of which flue-gas conduits operating in different conditions (wet) are to be installed.

The installation of the system of flue gas extraction consists in mounting all the necessary elements of the MKD system in compliance with one of the three versions.

In case of version 1 of the system of flue gas extraction, the chimney is usually based on stable foundation.

Table 4 and Fig. 4 present a typical set of profiles for the bottom part of the chimney conduit to be mounted inside a building on a stable foundation.


In case of installation of the system of flue gas extraction on the external wall of a building, in version 2 or 3, the chimney base does not usually rest upon a stable foundation but on a support (WKT part). A typical set of profiles for this version is shown in Table 5 and in Fig. 5. 5.

In case of chimneys of significant height, it is necessary to install transitional supports to take the load produced by the elements installed above a transitional support and to release the load of the lower elements.

A typical transitional support installed outside a building or on a load-bearing structure is shown in Fig. 6, and the set of profiles is presented in Table 6. The number of transitional supports and distances between them are presented in Table 8 and in Fig. 10.


The lengths of the system should be installed on the walls of the building or on the supporting structure with WHT construction clamps (5) in any version. Independently of the distance between the chimney and the wall or supporting structure, the clamps have appropriate regulation parts (see: technical drawing).

In case the chimney must protrude above the last fitting point to the structure or the wall of the building, the reinforced clamps KBS must be applied as they allow free installing of up to 3 m (up to Ø 225) and up to 2.5 m (up to Ø 250) of the chimney above the last fitting point. In such case, at the top part of the chimney two WHT clamps shall be mounted at the distance of 1 m from each other, and all the pipes above the last WHT and two pipes below the last WHT shall be clamped with KBS clamps.

The KFTZ plate with bent edge and the KFTP part may also be used as an element which provides transition from the MKS system to the MKD system. This is the case when the system of flue gas extraction has been made partly as a chimney liner in a traditional brick chimney, and partly as an external chimney of the MKD system. A typical application of the KFTP part as a transition from the MKS to the MKD system is presented in Fig. 7, and the set of parts is shown in Table 7.


An alternative solution for the bottom part of the chimney is presented in the figure.

The role of a cleanout and condensate collector is played by closing cover with the condensate collector (DH) which may be protruded after the KBT clamp has been removed. In the systems where no condensate is produced, the cover (D) without tube may be applied.


A – The height of the transition support for the chimney founded on a concrete slab.

B – The height of the transition support for the chimney installed on the WKT support.

C – Location of WHT clamps.

D – Maximum height of the chimney protruding above the last WHT clamp.


Any next transition support shall be mounted at the B distance from the previous one.


The effective chimneys for oil-fueled boilers should be minimum 5 m.

For gas-fueled appliances, the height of the flue-gas conduit in a one-story building and on the last floor of a multi-story building calculated from the opening of the draught breaker to the top edge of the flue gas outlet shall not be less than 2 m.

For ceilings or hipped roof ends penetrations, flashings (DDT 0, DDT 15, DDT 30, DDT 45) may be used together with rain caps (RKT). For tile roofs, parts with lead jacket are useful (DDTF). Fig. 9 presents an example of application of DDT 0, DDT 15, DDT 30, DDT 45 parts with relation to the inclination of the roof. Consecutive DDT parts may penetrate the roof within the following ranges of roof inclination:

In case of the flue-gas extraction system installed on its own load-bearing structure, the parts of the system provide installing a few flue-gas conduits on one load-bearing structure. Fig. 10 presents examples of the versions of the flue-gas extraction system on its own load-bearing structure.


Four flue-gas conduits assembled to one bearing-structure.

Three flue-gas conduits assembled to one load-bearing structure.

Two flue-gas conduits assembled to one load-bearing structure.

A single flue-gas conduit assembled to one load-bearing structure.


The mouth end (MAT), which is the end part of the flue-gas conduit, should be fixed at the outlet of the flue-gas conduit from the chimney. The RHT pipe (rain flange) is an alternative for the MAT pipe. The former is mounted directly on the last RT part, or in the MAT pipe.

After the installation of flue gas extraction has been completed, it is subject to approval which consists in the following checks:

- permeability of the flue-gas conduit ,

- tightness of connections,

- draught of the chimney,

- correctness of the connections and compliance of the flue gas removing parts with the design,

- standard outlet above the roof,

- compliance with the atmosphere protection standards.


The formal approval consists in the following:

- checking of the compliance of the installation with the design and documentation made after the installation has been completed,

- checking of the validity of the conformity certificates of the construction, insulation and assembly materials used in course of installation.

The acceptance of the flue gas extraction system should be attended by a licensed chimney sweep and a protocol should acknowledge the acceptance.