Tank o-ring burst, turn off tank or not?

[TaylorP]

Recreational diving : Tank on til on the surface.

 

[keyshunter]

Assuming that it is the VALVE o-ring (the one between the valve and the reg), I agree with Leadturn. If one is going to extrude (blow) it usually does it when the reg is first pressurized, or very shortly thereafter. A leaking O-ring at this location is very common and may happen at any time, but usually at the beginning of the dive when pressure is greatest and may or may not require an immediate trip to the surface. Many dive resorts are not very good about changing valve o-rings. I recently returned from a resort trip and I would bet that at least 25% of the divers were going merrily along with valve O-rings that had minor leaks.