PDA

View Full Version : DS-V use with non-balanced second stage?



band
09-18-2009, 05:47
Hello!

Is it possible to use non-balanced second stage (in my case from TUSA RS130) with Zeagle DS-V first stage?

Is DS-V over-balanced (as Aqualung LEGEND or all modern APEKS) or not?

IndyDiver
09-18-2009, 08:13
Hello!

Is it possible to use non-balanced second stage (in my case from TUSA RS130) with Zeagle DS-V first stage?

Is DS-V over-balanced (as Aqualung LEGEND or all modern APEKS) or not?

The DS-V is a balanced diaphram regulator. It is not over-balanced.

It is fine to use the RS130 with the DS-V as long as the intermediate pressure range of the two regs is set the same. The range of the DS-V is 135-150 psi, which is compatable with the Tusa. However, if the Tusa was last adjusted with a first stage that was producing 140 and the DS-V is producing 150, the setup might be a little twitchy.

Since the DS-V is balanced, the intermediate pressure it puts out is the same at any depth. This means the air pressure trying to push open the diaphragm in the second stage never changes; however, the water pressure trying to hold it closed increases with depth. Since the RS130 is not balanced, this leads to a minor increase in cracking perssure/breathing effort as you go deeper. This can be offset manually by the adjusting knob on the RS130.