my QEV is a QE-01. I had to enlarge the hole to put the pop off valve. pvc used instead of delrin with a very soft spring. I tested with a old refrigerator compressor through who apparently does a lot of pressure. But leaked air in nipple. I will take pictures.

I'm trying to build the system with full auto pop off valve, but air leaks from the nipple. Instead of delrin, pvc I used because I do not have delrin (where can I buy it or find it?). Must have a small hole in the disk? Sorry for the mistakes of English. Haha I'm Brazilian and new in the forum