went to LHBS today to get another hydrometer and a replacement for my now broken thief.he had a bag with used oval lids with pressure relief valve:rockin: I bought 4 for $9.00 a piece. what will be the best way to test them? I have plenty of empty kegs. The guy told me if some don't work, just bring em back and he will exchange until I get a full set working. Should I just fill them with water, pressurize and check back in a day? Thx in advance.