Freemie Cup parts are durable and will last up to a year with proper use and care. All cup sets have valves that are made from silicone and this part wears out over time through use. Replace valves every 2-3 months or sooner if use is heavy (i.e., use more than 4 times per day). Valves come in packs of (4) for about $20 and can be found here

Valves are the only part that needs to be replaced for maintenance purposes. 

You should check all parts before and after each session to look for damage. Always replace any parts that are damaged or worn.

Cup barriers are especially important and do the important job of keeping milk from your tubing and pump. Check this part carefully before/after every use. 

You should periodically check your flange size because the size needed can change over time. Fitmie inserts can size down breast flanges as your tissue changes.