If it's an Infamous II (Gen 4) timmy, I know that the Gen 4's original poppet valve had many problems, and as such they were replaced with a brass version (i think free as part of the warrantee from BLAST).
Perhaps an email to BLAST might result in them sending you a replacement part so it won't be a problem again.
Otherwise, out of all the timmys i've owned (a few now), i've not had one break on me yet whilst playing. Proactive maintainance on them will give you very good reliability overall.