Stop blaming torque; check your chuck liners

We lost half a shift last week chasing intermittent leaks on 5 gal tightheads. Line torques were in spec and the capper’s transducer trace looked clean. The root cause wasn’t torque at all: the chuck liners were glazed and a little hard, so the cap would slip right after the wrench released and during conveyor acceleration. The sensor saw “good,” the seal saw “not quite.” Drips didn’t show until pallets bounced in the warehouse.

Fix was simple but not free: swapped liners, added a torque-angle window, and moved liner replacement to a run-hours schedule instead of “when they look shiny.” We also started doing a quick mark-and-walk audit: paint mark across cap and neck, check for back-off after 30 minutes. It’s low tech and kept us honest.

For those running chemicals: how do you set PM intervals for capper consumables? Any cheap in-line tells you like to use to catch slip or cross-thread before the complaint shows up?