Spectra duckbill valves should be replaced every 4 to 12 weeks.

How often do Duckbills need to be replaced?

Duckbill valves (1-3 months)

Once daily expressing or less: You should expect to replace these once-piece valves every 2-3 months.

How do I know if my duckbill valve is bad?

If you notice a decrease in suction or if you've noticed your pump doesn't feel as strong as before and you're getting less milk, take a good look at your valves. If it has been more than a month since you have replaced them or if there is a tear in your valve, it's time to replace it.