Vaillant Elbow 45°, Ø 160 mm

Product detailed description

45° Elbow Ø 160 mm – gentle change of direction with low resistance

Where the route of a cascade boiler room's common flue collector does not require a sharp, nearly right-angle change of direction, but only a milder "deviation" – for example bypassing a column, an air-handling duct run, or a diagonal passage between two height levels – an elbow with a 45° angle is the more suitable choice. Compared to an 87° elbow, it presents lower resistance to flue gas flow (a smaller deflection angle means a smoother change of flow direction), which is especially beneficial on longer routes or in cascades with multiple boilers, where the total resistance of individual fittings along the route adds up and affects the required draft/exhaust performance.

As with the 87° elbow, two 45° elbows connected against each other with a short straight section between them can bridge a lateral shift of the route (i.e. "bypassing" an obstacle) while maintaining the original direction of the pipe continuation beyond the obstacle.

Exhaust systems for Vaillant cascade boiler rooms

When a single condensing boiler is not enough to cover the heat demand of a building – an apartment building, hotel, operational hall, office building or a larger technological boiler room – this is usually solved not with a single large boiler, but with a cascade of several smaller or medium-output Vaillant condensing boilers connected in parallel. The advantage of a cascade solution is higher operational reliability (the failure of one boiler does not mean a heating outage for the entire building), better output regulation according to current demand (both the number of running boilers and the output of each can be modulated), and easier future expansion of the boiler room with an additional boiler if heat demand increases.

Each boiler in the cascade has its own flue gas exhaust and combustion air intake port, but for practical, economic and construction reasons, the flue gases of all boilers are usually led out through one common flue collector (manifold) into a single chimney or through a single roof/facade penetration. This is exactly the purpose of the range of components described below – parts of a separate (not concentric) flue exhaust system with a diameter of 160 mm or 200 mm, which connects to the ports of individual boilers and joins them into one common pipe.

The system is modular – it consists of basic connection kits (for the first two boilers of the cascade, including the necessary fitting for condensate drainage), extension kits (for each additional boiler added to the cascade), individual elbows of various angles for bypassing obstacles and changing route direction, extensions of various lengths for bridging the distance between the boilers and the riser, and finally a kit for connecting the whole assembly to a masonry chimney shaft.

Typical placement in the assembly

The 45° elbow Ø 160 mm is most often used in pairs – one to deviate from the original axis of the route, the other a bit further along to return to the original direction, thus bypassing an obstacle without the need for a sharper, more resistant 87° elbow. It is also used for a diagonal passage of a vertical riser through a floor or partition structure, where it is not possible to route the pipe exactly perpendicularly.

The part is fully compatible with other components of the Ø 160 mm range and connects using an identical socket joint with a sealing ring.

Material and construction – why polypropylene (PP)

All parts of this range are made of polypropylene (PP) – a plastic used in exhaust systems of condensing boilers precisely because it perfectly withstands the chemically aggressive condensate that naturally forms during the operation of condensing equipment. A condensing boiler, compared to a classic (non-condensing) boiler, also utilizes the latent heat contained in the water vapor of the flue gases – this vapor is cooled below the dew point in the flue gas heat exchanger and condenses, and the resulting condensate is mildly acidic (pH approximately 3–5, depending on the type of fuel and operating conditions). Metal (e.g. stainless steel) flues can also withstand this load, but plastic PP systems are lighter to handle, faster to install thanks to joints with sealing rings without the need for welding or special tools, and, at comparable quality, are usually also more cost-effective.

The operating temperature of flue gases in condensing boilers is relatively low (typically up to approx. 80–120 °C depending on the operating mode and boiler output) – this is precisely why the use of plastic PP piping instead of a classic metal flue (common, for example, in older atmospheric or low-temperature boilers) is not only possible but also more suitable in terms of resistance to condensate. The system is certified and dimensioned by the manufacturer directly for cooperation with Vaillant condensing boilers of the corresponding output range and port type designation.

The joints between individual parts are designed as socket connections with a rubber sealing ring (so-called socket joint) – this construction allows for simple, tight yet demountable installation without gluing or welding, which greatly simplifies any future route modifications, replacement of a damaged part, or expansion of the cascade with another boiler.

Practical example

In a boiler room where the cascade's collector pipe must bypass an existing supporting column in the middle of the room, two 45° elbows are used with a short straight extension between them – the pipe thus smoothly deviates around the column and returns to its original axis afterward, toward the riser. Such a solution presents significantly lower resistance to flue gas flow than a pair of 87° elbows, which is beneficial especially in cascades with a higher total output, where the sum of resistances of all fittings along the route is an important parameter in exhaust system design.

Comparison of elbow angles within the Ø 160 mm range

The 160 mm elbow is available in four angles – 87°, 45°, 30° and 15° – each having its own typical place of use in practice. The 45° elbow represents a middle choice between the sharp 87° elbow (for a nearly right-angle change of direction) and the gentle 30°/15° elbows (for minor corrections of the route axis). When designing the route of a cascade's collector branch, it is advisable to always choose the mildest angle that still resolves the required change of direction – this reduces the overall flow resistance as well as the number of fittings needed.

Ordering: Since elbows with different angles have different order numbers (45° = 0020095556, 87° = 0020095552, 30° = 0020095558, 15° = 0020095560), we recommend always verifying the exact angle according to the route's project documentation before ordering, to avoid having to replace an already installed part with the wrong angle.

Assembly and installation

The installation of the flue gas exhaust system for gas appliances (including cascade boiler rooms) in Slovakia is subject to the requirements of the standards STN EN 1443 (Chimneys), STN 73 4201 (Chimneys and flues) and related gas industry technical rules (TPP), and must be carried out by an authorized and professionally qualified person – an authorized service technician or an installation company holding the relevant authorization for installing gas appliances and their exhaust systems. Commissioning of the boiler room also includes an inspection of the chimney/flue carried out by a chimney sweep company and the issuance of the relevant inspection report.

When designing the route of a cascade flue, it is necessary to take into account in particular: the total rated heat output of all boilers in the cascade (this determines the required diameter of the collector pipe – 160 mm or 200 mm), the maximum permissible route length and number of elbows (the manufacturer specifies equivalent lengths for individual fittings), the slope of horizontal sections back toward the boiler or condensate separator (generally at least 3°, so that condensate can flow away by gravity and does not remain standing in the pipe), sufficient securing of the pipe with spacer brackets at regular intervals (typically every 1–1.5 m) so as to prevent sagging or excessive stress on the socket joints, and maintaining access to inspection openings and inspection elbows for regular cleaning and inspection of clear passage.

When connecting several boilers in a cascade to one common collector pipe, it is also necessary to respect the order and direction of feeding the individual branches according to the manufacturer's installation instructions (including the recommended use of check flaps in cascades with three or more boilers, so that when one boiler is shut down, flue gases from the running boilers do not flow back into the shut-down unit) and to maintain the prescribed minimum rise and routing toward the common chimney or facade/roof outlet.

Maintenance of the elbow during operation

The 45° elbow does not have its own inspection opening; its condition is therefore checked together with the rest of the route during the regular annual inspection of the boiler room, usually via the nearest available inspection point. Due to the milder deflection angle (compared to the 87° elbow), the likelihood of deposits accumulating in this type of elbow is generally lower, since the flue gas flow passes through it more smoothly.

Storage and handling before installation

The same principle applies to storing the 45° elbow before installation as for other PP fittings in this range – keep it in a dry environment away from direct sunlight and protect the sealing ring in the socket from mechanical damage until it is built into the assembly. Upon receiving the goods, we recommend visually checking the integrity of the seal and any scratches or cracks on the surface of the part before installing it into the route.

Service, cleaning and service life

Regular inspection and cleaning of the exhaust system is part of the standard annual service inspection of a condensing boiler room. Thanks to the inspection openings and inspection elbows in the assembly, individual sections of the pipe can be checked and, if necessary, cleaned (e.g. of any deposits) without the need for complete disassembly of the entire route. The condensate separator, if part of the assembly, needs to be regularly checked and, if necessary, emptied/flushed to prevent it from clogging and condensate backing up into the pipe.

The service life of a quality PP exhaust system from the manufacturer, directly compatible with the given boiler range, is comparable to the service life of the boiler itself when properly installed and regularly serviced – that is, roughly 15 years or more of operation. When replacing or adding individual parts in the future (for example, when expanding the cascade with another boiler), it is advisable to use original components of the same manufacturer and diameter to maintain full compatibility of joints as well as the validity of the warranty for the entire exhaust system.

Frequently Asked Questions

Why buy this Vaillant accessory at ATRIA.SK

If you only need a mild change of direction in the route of a cascade flue and also want to minimize flue gas flow resistance, the 45° elbow Ø 160 mm is a more suitable and often also more cost-effective choice for this purpose than the sharper 87° elbow.

When purchasing any part of an exhaust system, we are happy to advise you on selecting the correct combination of components for your specific boiler room – just contact us with details about the type and number of boilers, or with the project documentation. We usually dispatch goods within 24–48 hours of ordering; for larger assemblies, we will inform you in advance of the delivery date if necessary.