Ok, let me get this straight...
You connected the air compressor to the quick connect at the left end of this pic.
Between the quick connect and the QEV, you had a blowgun. (no ballvalve, at first.)
Then, -leaving the air compressor connected- you fired the blowgun, to trigger the QEV.
Is that right ?
I could be completely wrong but that is how your first couple of posts read. And I am just curious if that is an accurate description.