O-Ring Size Between Valve and Tank

They are 22×3.5mm size. However, I'm not sure if they are duro 70 or 90. I have a feeling that they are harder than the standard O-rings, so probably duro 90. If you're using the softer O-ring that may be why they are blowing out...

Did the 22 x 3.5 duro 90 work? Mine blew yesterday and can't find o-ring specification. My threads are 7/8" (22mm) and gasket set depth on bottle 0.1" (2.5mm). Bottle o-ring seat is ~28.3mm. I crammed a Home Depot 15/16" x 1/8" o-ring. Held for about 12 hours then started to leak. 

The 3.5mm seams a little thick.