The gap between the torque eliminators is the same as the gasket thickness (.028”). If the gasket is missing, the torque eliminators bottom out into a “fail safe” mode. This prevents torroid to torroid contact and destruction. The fitting cannot pass leak check with the gasket missing.
The legacy metal face seal fitting, if tightened without a gasket, will crush both torroids. The only remedy for this is to replace both glands. Cutting off and rewelding new glands is a particle generating, time consuming, and expensive remediation operation.
Tightening a legacy fitting without a gasket may even seal and give a false positive leak check reading. If a gas system is certified in this manner it may later develop a leak due to the damaged torroids. A leak that initiates when process gases are present is a much more dangerous situation especially if the gases are corrosive, toxic or pyrophoric.