Vaillant flue elbow 87°, Ø130 mm

Product detailed description

Vaillant flue elbow 87°, Ø130 mm

The 87° elbow with a diameter of Ø130 mm is an original part of the Vaillant flue system designed to change the direction of the flue gas path by almost a right angle. It is the sharpest elbow in the whole range of angled parts offered by the manufacturer (87°, 45°, 30°, 15°), used where the flue gas duct needs to be bent practically perpendicularly - typically when transitioning from a horizontal duct from the boiler to a vertical shaft, when bypassing a structural obstacle requiring a significant change of direction, or when passing through a wall. Made of polypropylene (PP) resistant to condensate and to the temperatures of flue gases from condensing operation, the elbow is part of a comprehensive Ø130 mm accessory range together with straight extensions, gentler elbows (45°, 30°, 15°), an inspection T-piece, connection and extension sets (S1, S2, S3), and spacer brackets.

Technical characteristics

• Bend angle: 87°
• Nominal diameter: Ø130 mm
• Material: polypropylene (PP), resistant to condensate and to the flue gas temperatures of condensing operation
• Operation type: pressurized (type C), suitable for condensing boilers with forced flue gas extraction
• Maximum operating temperature: approx. up to 120 °C
• Joint type: plug-in (socket) joint, with rubber seal at both ends
• Packaging: 1 piece
• Manufacturer: Vaillant Group
• Warranty: 2 years

Why 87° and not a full 90°

Most flue system manufacturers, including Vaillant, choose an actual angle slightly below 90° (in this case 87°) for "right-angle" elbows instead of a mathematically exact right angle. The main reason is flow dynamics - an elbow with a slightly gentler angle than exactly 90° offers somewhat lower resistance to flue gas flow and better maintains flow continuity at the bend, which contributes to a lower overall pressure resistance of the flue gas path under the pressurized operation of a condensing boiler. In practical terms, this elbow functions in an installation practically the same as a classic "90-degree" elbow used in ordinary heating practice - that is, for bending the route when transitioning from horizontal to vertical routing or vice versa.

When to choose the 87° elbow instead of gentler angles (45°, 30°, 15°)

The Vaillant flue accessory range offers elbows in four different angles, allowing the flue gas path to be precisely adapted to a specific construction situation. The 87° elbow is a suitable choice in the following cases:

• when transitioning from a horizontal boiler outlet directly into a vertical shaft or chimney (a classic "L" configuration),
• when it is necessary to bypass a structural obstacle (e.g. a ceiling beam, another installation's piping) with a significant bend in the route,
• when the flue gas path passes through a wall into an adjacent space, requiring a change from vertical to horizontal routing,
• anywhere a single significant change of direction is needed over a short section, instead of several gentler elbows in a row.

Conversely, gentler angles (45°, 30°, 15°), which in this product range are sold in packs of two, are used where only a slight correction of direction is needed (for example, compensating for a slightly uneven shaft), or where it is preferable to distribute a larger change of direction into two gentler bends instead of one sharp elbow - for example, to maintain smoother flue gas flow over longer routes, or for spatial reasons at the installation site.

Installation

Installing the 87° elbow is straightforward thanks to the plug-in (socket) joint system with a rubber seal; nevertheless, it should be carried out by a professionally qualified person as part of the complete flue gas path installation:

1. Check the correct orientation of the elbow according to the direction of the intended change of route (horizontal/vertical connection).
2. Insert the elbow into the adjoining parts (extension, connection set, T-piece) all the way to the stop, checking that the rubber sealing ring is properly seated at both ends.
3. Provide mechanical support at the bend (e.g. using a spacer bracket), as the elbow represents a point of increased mechanical stress compared to a straight section.
4. Check that the minimum required slope (approx. 3°) is maintained on the adjacent straight sections for proper condensate drainage, even after inserting the elbow into the route.
5. Visually check the tightness of the joint after completing installation.

Compatibility

The 87° Ø130 mm elbow is fully compatible with the entire range of Vaillant flue accessories of the same diameter - straight extensions (1.0 m and 2.0 m), gentler elbows (45°, 30°, 15°), the inspection T-piece, spacer brackets, as well as connection and extension sets (S1, S2, S3 including the Ø150/130 mm reducer for ecoCRAFT boilers). Thanks to the unified plug-in joint system, the parts can be freely combined according to the needs of a specific installation.

Effect of the elbow on condensate drainage

When bending the route at a larger angle (as is the case with the 87° elbow), correct positioning of the elbow relative to the direction of condensate flow is particularly important. In most configurations, it is advisable to position the elbow so that condensate forming in the upper (cooler) part of the route flows smoothly through the elbow downward toward the nearest drainage point (e.g. the inspection T-piece), without risk of accumulation at the bend. When designing a route with multiple elbows, we recommend taking this condensate flow logic into account already at the design stage, not only afterwards during installation.

Why an original Vaillant part

An elbow is a point of increased mechanical and flow stress compared to a straight section of pipe - it is precisely here that the direction of both flue gas and condensate flow changes, placing higher demands on shape precision and the quality of sealing elements. The original Vaillant elbow is designed and tested to reliably withstand this stress long-term in combination with the other parts of the range, unlike universal alternative parts, where the same shape precision and sealing system compatibility may not be guaranteed.

Frequently asked questions

Effect of the elbow on the pressure loss of the flue gas path

Every elbow in the flue gas path represents a local resistance to flue gas flow, which adds to the total pressure loss of the route calculated during installation design. In condensing boilers with forced (fan-assisted) flue gas extraction, this pressure loss is an important parameter affecting the setting of the boiler's flue gas fan output and must remain within the limits specified by the manufacturer for the given combination of route length and number of elbows. The boiler manufacturer usually specifies the maximum permissible number of elbows or the maximum equivalent route length (where each elbow is converted to an equivalent length of straight pipe) for a given boiler model and output - when designing a more complex route with multiple elbows (for example, a combination of an 87° elbow and several gentler angles), it is therefore advisable to verify compliance with these limits with a designer or directly in the boiler's technical documentation.

For this very reason, an elbow with a pronounced bend angle (such as 87°) should only be used where a single significant change of direction is genuinely needed, rather than unnecessarily combining a large number of elbows on a route that could be solved more simply with fewer changes of direction.

The complete Vaillant Ø130 mm flue system - where this elbow fits in

The 87° elbow is one of four angled parts in the Vaillant Ø130 mm flue accessory range (87°, 45°, 30°, 15°), which also includes straight extensions (1.0 m and 2.0 m), an inspection T-piece with an inspection and cleaning opening, spacer brackets for mechanically securing the pipe, as well as connection sets for connecting to the boiler (S1, S2, optionally with a Ø150/130 mm reducer for ecoCRAFT boilers) and an S3 extension set for cascading additional boilers. Thanks to the unified diameter and plug-in joint system, these parts can be freely combined to assemble a complete flue gas path exactly according to the layout of a specific boiler room - from a simple direct connection to a chimney to more complex routes with multiple changes of direction and cascade connection of several boilers.

Practical example of use

A typical scenario for using the 87° elbow is a situation where an ecoCRAFT condensing boiler is located in a basement or ground floor of a building with the flue gas outlet oriented horizontally from the rear of the boiler, while the vertical chimney shaft is located in an adjacent room or several meters further within the same room. In such a case, the route is usually solved with a short horizontal section (straight extension, or a connection set) from the boiler, followed by the 87° elbow to change direction into a vertical position, and then continuing vertically upward toward the shaft or roof outlet. The exact opposite configuration (an elbow at the transition from a vertical shaft to a horizontal section toward the boiler) is equally common, depending on the layout of the specific boiler room.

Maintenance and inspection

During regular inspections of the flue gas path (carried out by an authorized chimney sweep), special attention should be paid to elbows, as these are points where any impurities may accumulate or where sealing elements may experience slightly increased wear due to the change in flow direction. The following are checked in particular:

• the tightness of both plug-in joints of the elbow,
• the patency of the internal space (absence of deposits or obstructions at the bend),
• the mechanical fastening around the elbow,
• the overall visual condition of the elbow body (absence of deformation or mechanical damage).

Standards and legislation

Installation of the elbow and the entire flue gas path must comply with applicable standards (STN 73 4201, STN EN 1856, STN EN 14471) and must be carried out by a professionally qualified person, with a subsequent inspection by an authorized chimney sweep before the boiler is put into operation. When changing the direction of the route, it is also necessary to observe the minimum clearance distances from combustible structures according to applicable regulations, as an elbow may bring the pipe closer to building structures than a straight run.

Storage and handling

Before installation, we recommend storing the elbow in a dry environment protected from direct sunlight and from mechanical damage to the sealing surfaces at both ends. When handling, protect the shaped body of the elbow from impact, which could affect the accuracy of the bend angle or the tightness of the joint.

Ordering for service and installation companies

The 87° elbow is among the most frequently ordered angled parts when installing and servicing Vaillant flue systems, as the combination of a horizontal boiler outlet with a vertical shaft or roof outlet is one of the most common boiler room layouts. Service and heating companies therefore commonly keep it in sufficient stock so they can respond flexibly both to new installations and to the replacement of a damaged part during a service intervention without unnecessary waiting for delivery.

Summary

The 87° Ø130 mm elbow is a basic part for handling a significant change of direction in the Vaillant flue system, particularly suitable for transitioning between horizontal and vertical flue gas path routing. Combined with the other parts of the range (extensions, gentler elbows, T-piece, connection and extension sets, spacer brackets), it allows a complete route to be assembled exactly according to the layout of the boiler room. We recommend purchasing only original Vaillant parts and entrusting installation to a professionally qualified and duly authorized person, with subsequent inspection of the functionality and tightness of the entire flue gas path by an authorized chimney sweep before the boiler is put into operation and at regular intervals set by applicable legislation throughout the entire operating life of the boiler.