Manifold open or closed?

[RTBCAT]

Reading some of the threads and it seems to me alot of people dive with their manifolds open. At depth if you have a leak you have to be very fast to shut off your tank valve inorder to not loose alot of air. With it closed you have two completly seperate systems which can be turned into one if need be. The only thing is you have to switch regs and pay more attention to your gas supply. Seems safer to me.

 

[farrakhan]

I dive with my manifold open ALL the time. If I wanted to switch regulators I would just dive with twin independants. If you are taking too much time closing your manifold then practice practice practice. Seems kind of a needless piece of equipment if you are switching regulators anyway.

 

[matt_unique]

Reading some of the threads and it seems to me alot of people dive with their manifolds open. At depth if you have a leak you have to be very fast to shut off your tank valve inorder to not loose alot of air. With it closed you have two completly seperate systems which can be turned into one if need be. The only thing is you have to switch regs and pay more attention to your gas supply. Seems safer to me.

To dive with (and capitalize on the benefits of) an isolator you must be able to open/close all your valves quickly.

 

[GDI]

Dive with it open. The time for a complete shut down of valves and to reopen them switching regs as required should take you less than 1 minute. You need to practice this.

 

[novadiver]

Reading some of the threads and it seems to me alot of people dive with their manifolds open. At depth if you have a leak you have to be very fast to shut off your tank valve inorder to not loose alot of air. With it closed you have two completly seperate systems which can be turned into one if need be. The only thing is you have to switch regs and pay more attention to your gas supply. Seems safer to me.

Why would you dive with it shut? With proper gas management, you'll never need more than 1/2 of what you have left. and that will only happen if you have a failure at your turn.

 

[wedivebc]

Reading some of the threads and it seems to me alot of people dive with their manifolds open. At depth if you have a leak you have to be very fast to shut off your tank valve inorder to not loose alot of air. With it closed you have two completly seperate systems which can be turned into one if need be. The only thing is you have to switch regs and pay more attention to your gas supply. Seems safer to me.

I dive with mine closed. I frequently dive wrecks and there are situations where arm movement is restricted. In the event of a failure I know I can reach my second reg but not always can I reach my manifold easily.
GDI, 1 minute is a very long time when you are losing gas. Try this after a dive sometime, record tank pressure, shut your tank valve, remove an inflator hose from the first stage then open the tank valve fully for 1 minute. Then replace the hose and record pressure. That is what would happen if you snagged and tore a LP hose.
Now imagine that happened to your left side (assuming 1 spg) just at the point where you were turning your dive. You have lost X amount of gas you don't know how much cause your spg is shut down and you have to get out of the wreck. If you can still see your buddy or your guideline you are in good shape but all those bubbles sure can silt things out in a hurry.

 

[Soggy]

Reading some of the threads and it seems to me alot of people dive with their manifolds open. At depth if you have a leak you have to be very fast to shut off your tank valve inorder to not loose alot of air. With it closed you have two completly seperate systems which can be turned into one if need be. The only thing is you have to switch regs and pay more attention to your gas supply. Seems safer to me.

By diving with it closed, you've effectively created independent doubles, only with more failure points. If you want to dive independents, dive independents...if you want to dive with an isolator, dive with it open.

 

[novadiver]

I dive with mine closed. I frequently dive wrecks and there are situations where arm movement is restricted. In the event of a failure I know I can reach my second reg but not always can I reach my manifold easily.
GDI, 1 minute is a very long time when you are losing gas. Try this after a dive sometime, record tank pressure, shut your tank valve, remove an inflator hose from the first stage then open the tank valve fully for 1 minute. Then replace the hose and record pressure. That is what would happen if you snagged and tore a LP hose.
Now imagine that happened to your left side (assuming 1 spg) just at the point where you were turning your dive. You have lost X amount of gas you don't know how much cause your spg is shut down and you have to get out of the wreck. If you can still see your buddy or your guideline you are in good shape but all those bubbles sure can silt things out in a hurry.

Do you also have two SPGs ? and what do you do when you switch regs only to find your other tanks bone dry? Not me folks, I'll keep my isolater open.

 

[wedivebc]

Do you also have two SPGs ? and what do you do when you switch regs only to find your other tanks bone dry? Not me folks, I'll keep my isolater open.

Yes 2 spgs and I monitor my gas so empty tanks won't happen. If it did though I could turn the dive and finish with my reserve.

 

[novadiver]

Yes 2 spgs and I monitor my gas so empty tanks won't happen. If it did though I could turn the dive and finish with my reserve.

Fair enough, I've just never seen anyone close their iso on purpose.I will say that I used to close my isolation on my tanks when I travel with them, but I forgot to open it when I got it filled and they only filled one side. That sucked when I got to the dive site , opened the manifold, and watched my gas drop as the other side filled.