Quick manifold question

[MaxPower]

May be a dumb question, but a manifold has three valves (L, R, and isolator), if you shut down either the L or R valve, does it only shut down the regulator, or the reg and the tank as well? What is the procedure with a free flo on doubles? Thanks!

 

[DA Aquamaster]

The knobs of the L and R posts shut down the respective regulators while the isolator valve in the center isolates the gas in one tank from the other.

So in effect, the L or R knobs are used in the event of a regulator failure or freeflow while the isolator valve is used to preserve the gas supply in the event of a tank related failure such as leaking neck o-ring or a failed burst disc.

It is important to note that with the isolator open, you can use the contents of both tanks with either regulator with the other regulator shut off. But if you close the isolator, you can no longer use the regulator on the "bad" side of the isolator once the contents of that tank are lost.

 

[TSandM]

If you have a free flow, you shut down the post that's free flowing and breathe the other regulator. You still have access to all the gas in both tanks. This is true for any malfunction from the first stage on down. The only problems that would require shutting the isolator are the ones that involve the manifold itself, or the tank o-ring. When you have to close the isolator, you've accepted that you are going to lose half of your gas.