• O-RINGS on a scuba tank create an air tight seal bet ween the scuba tank valve and the first stage of a scuba regulator.

Quick Facts and Tips : O RINGS on a scuba tank create an air tight seal bet ween the scuba tank valve and the first stage of a scuba regulator. Buna-N is a common trade name for nitrile rubber, while Viton is a trade name for Fluorocarbon rubber. Viton has better chemical and temperature resistance than Buna, but Buna is usually less expensive. Viton O -rings are 02 Compatible – Buna rings are not.