Coriolis vs weigh-scale on flammable drum lines

At our Louisville plant we recently revamped a Class I, Div 1 drum line for flammable blends. We swapped floor scales and manual valves for Coriolis-based, bottom-up semi-auto fillers with a two-stage profile, nitrogen blanket, and bonded/grounded swivels. Result: cycle time per 55-gal dropped 21% (73s to 58s), giveaway fell from 0.15% to 0.08%, and vapor exposure is noticeably lower because we stay closed until bung torque.

Not all roses: entrained air on solvent returns confused the meters until we added backpressure control and a short recirc loop. We fought with load certs too; customers buying by weight still want legal-for-trade evidence, and many C1D1 Coriolis packages aren’t NTEP certified. Static control and hose resistance per NFPA 77 mattered more than the brochure suggests.

For folks in oil and petrochemical terminals: have you made the same shift from weigh-scale to mass flow on drums or totes? What tripped you up in C1D1, and would you do it again?