Pneumatic dosing systems for pigment granules are designed to reliably support manufacturing processes at concrete production facilities over many years. It is not unusual for these systems to have a service life of more than three decades when maintained regularly. Changes do not affect the system itself as a general rule but rather its wear parts and operating environment. Pinch valves are subject to natural wear and tear; filters become clogged over time; foreign matter may be carried in with the raw material; and moisture can lead to deposits in the weighing hopper. These ageing and wear processes are part of normal system operations.