Delivery lines are the arteries of any concrete pump; ignore them and the whole system clogs. Zoom GlobalMech Corp recommends a three-phase cleaning protocol after every pour. Phase 1: immediately push a water-soaked sponge ball (oversized by 10 %) to scavenge loose mortar. Phase 2: follow with a 2 % caustic soda solution to dissolve dormant cement particles—let it soak 15 minutes but never exceed 30 minutes or you risk etching the inner wall. Phase 3: finish with clean water until runoff pH matches supply water. Record the final pH in the logbook; values above 9 indicate incomplete cleaning and predict scale build-up.