The geometry of the duct channel is designed to minimize the accumulation of the dust. We don’t suggest your modification. The expansion joint suggested by Teli has also a bigger risk to create accumulation of dust which can block it. We suggest Teli to follow our design.2. H202: Are the six rotating connections shown in the picture supplied by ENGETIC? See Annex 3 H202-connection.The connections are part of the supporting structures which are in TELI scope