Yes, as has been mentioned already, a push and a twist puts it in storage mode and pushing the purge inward releases it. No, it is impossible for it to lock in use. As to extending service intervals, that depends upon the desire to get the parts for life if qualified. In which case it just maintains the performance for the two year service interval, if not, then yes it would extend the service interval for seat replacement.I see the G260 has an adjustment on the purge that basically puts it in "storage mode" and supposedly extends the time in storage between service events?
James