I've been wondering how many hours you should get out of the number 2 jets on a ti wand. I run 400-500 psi and it's probably been 18 months - is it time??
Greenie has told me once a year or when you see the spray pattern change. I changed mine at a about year and about 500 hours and they were probably good. I kept the old ones as spares.
but they're not all that expensive, so we change out every year or two
soak the old ones in a descale solution to clean up, then keep 'em on board.
That way when/if a jet fouls with debris on occasion, just change the jet, rather than monkeying around clearing and re-installing a fouled jet while on the job