I think my perma-seal isn't giving a good seal anymore after 4-5 swaps. I did a swap of my co2 tank this morning and I could hear hizzing sound coming out, I disconnect and make sure everything is tight and still I could hear gas is coming out. I have a couple nylon washer, so I used it instead and it sealed perfectly. Are there any better quality perma-seal or basically all the same? I probably will only use a new nylon washer from now on.