Yes, and that is what is called purging. currently, the value is
so every node that uses the default size of 300MB will drop the transactions that have fees of less than 23.2sat/vb but nodes use custom mempool size so the transaction will likely stay longer because it stays in some nodes.
So the transaction will be dropped just meet one of the following conditions, is it right?
1. purging: take the above figure as an example, every node that uses the default size of 300MB will drop the transactions that have fees of less than 23.2sat/vb.
2. drop: the default is 14 days which is still subjected to the conditions stated above reply, which depends on node's config.
Yes, nodes have their custom setting, mempool size but nodes will drop the transactions which is unconfirmed for 14 days or above unless it is rebroadcasted or the transaction can be dropped earlier too, if the fee used is far less than the purging rate.