Decompression unit

1. A typical ceramic pipe section. In total some 6800 must have been produces by the army.
2. The smaller end of one segment was put in the wider end of the other and sealed with special mortar.
3. A kind of decompression unit to prevent that the pressure in both pipes could harm the aqueduct. On top of both ‘overtures du regard’ (inspection holes) vertical pipes were places with a diameter of about 12 cm, which were open on top to give room to the pressure