The Scania exhaust bellows consists of 2 flexible sections with several layers of corrugated stainless steel plate that are connected to a short pipe. The exhaust bellows can absorb both longitudinal and lateral movements. It allows a maximum simultaneous lateral movement of ±20 mm and a longitudinal movement of ±10 mm. The exhaust bellows has an inside diameter of 127 mm and flanges that are secured with a V-clamp. It is supplied with a loose flange that is welded to the pipe which is to be connected to the exhaust bellows.
Scania DI09, DI13, DI16 Sound reduction
Assess the need for sound reduction in new installations from case to case, based on the applicable conditions in relation to noise requirements, length and type of exhaust system, location of the exhaust system outlet etc. Some form of sound reduction is required in most installations. The thermal insulation of the exhaust system affects the sound level. A thermally insulated system can result in a higher noise level than an uninsulated system.
Scania DI13 Exhaust noise
Undamped exhaust noise, measured 1 metre downstream of the turbocharger at full power output:
The most important frequency range for exhaust noise is between 50 and 500 Hz. Exhaust flow in the system can generate hissing sounds, e.g. at sharp pipe bends and edges. This is known as self-generated sound. This phenomenon occurs higher up in the frequency range and is effectively dampened with an absorption silencer (e.g.glass fibre). Vibrations in the silencer casing can also generate noise. For this reason, avoid silencers with flat surfaces.
Scania DI09, DI13, DI16 Exhaust system design
Position the silencer as close to the end of the exhaust system as possible. In order to obtain the best noise reduction, there should only be a short tailpipe after the silencer as shown in the graph.
- For all-speed engines, read the specified maximum speed for the engine.
- For single-speed engines, read the operating speed of the engine.
If the silencer cannot be positioned close to the exhaust system outlet because of a lack of space, it should be placed as close to the engine as possible. This location is,however, unfavourable in silencing terms if the pipes beyond it are long. It may then be a good idea to install another silencer close to the outlet or to end the exhaust system with two 90° pipe bends with a suitable length between them.
Scania DI09, DI13, DI16 Exhaust outlet
Design the exhaust system so that the exhaust gases are not reflected against vertical walls, since this results in increased noise level. Position the exhaust outlet so that no exhaust gases can be drawn into the engine intake. If exhaust gases are drawn into the intake, intake air temperature increases rapidly. The exhaust gases contain soot particles so there is also a risk of the air filter becoming blocked.
Connection of exhaust system to engine
There should always be a flexible connection between the exhaust system and the engine which absorbs the movement of the engine and changes in length in the exhaust system due to temperature changes. A flexible connection can consist of the Scania exhaust bellows. Position the flexible connection as close to the turbocharger connection as possible.
Scania DI09, DI13, DI16 Dry exhaust pipe bends
The engines can be equipped with a 90° exhaust pipe bend on the turbocharger exhaust outlet. The exhaust pipe bend can be fitted at different angles and rotated 360° around the connection with the turbocharger.
The exhaust pipe bend is connected to the turbocharger with a V-clamp. The exhaust pipe bend outlet has a flange that is connected with a V-clamp. It is usually connected directly to the Scania exhaust bellows. On DI16 XPI a flange is connected between the turbocharger and exhaust pipe bend. The flange, which is marked in grey in the illustration, is connected with 4 Ø 11 mm screws.
- Exhaust pipe bend for the DI13 072/077.
- Exhaust pipe bend for the DI09, DI13 except for 072/077 and the DI16 The flange marked in grey is only used on DI16 XPI.
Water-cooled exhaust pipe bends Scania DI09, DI13
For engines with heat exchangers, there are also water-cooled exhaust pipe bends. They have outlets to fit an exhaust gas temperature sensor (1), thread 1/8-27 NPTF. The upper illustration shows an example of a water-cooled exhaust pipe bend for DI09 and DI13. The table gives the measurements for all water-cooled exhaust pipe bends for DI09 and DI13.
Scania DI13 Exhaust system For Free