What is an overbalanced first stage and what are the advantages and disadvantages of this? (ie: Apeks DST/DS4).
What is an "overbalanced" first stage?
- Thread starter Atticus
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
I believe it means that as depth increases, IP increases slightly (as opposed to staying constant, as in balanced first stages).
I also believe that I've read it helps because the gas is slightly more viscous (or something) at extreme depths. I don't think there are any disadvantages.
I also believe that I've read it helps because the gas is slightly more viscous (or something) at extreme depths. I don't think there are any disadvantages.
R
redacted
Guest
Sounds like a BD design where IP increases as tank pressure decreases - until tank preasure falls below IP of course. The increase can't be too much or you could have problems with higher WOB on a full tank or freeflow as tank preasure decreases.
Seems to me that the biggest advantage would be an advertising gimick. But I'd hope someone else can come up with a real benefit to the diver.
With an unbalanced piston 1st, the 10 to 20 psi drop in IP does become noticable to the user in WOB, especially at depth. But small changes in IP, as I would expect from an "overbalance" BP, should be unnoticable to all but true royalty.
Johnythan's explaination makes more sense. May have even been addressed in Oxyhacker's book.
Seems to me that the biggest advantage would be an advertising gimick. But I'd hope someone else can come up with a real benefit to the diver.
With an unbalanced piston 1st, the 10 to 20 psi drop in IP does become noticable to the user in WOB, especially at depth. But small changes in IP, as I would expect from an "overbalance" BP, should be unnoticable to all but true royalty.
Johnythan's explaination makes more sense. May have even been addressed in Oxyhacker's book.
OP
Thanks guys. The reason I'm asking is that it has been suggested that the DST (or DS4 for that matter) and ATX 50 is not appropriate for use at depths in the 200-300 foot range due to the first stage being overbalanced and due to a limited flow rate. I'd like to understand the first statement, and verify if the second statement is accurate.
Tell that to the WKPP divers who apparently use them at 300+ feet as a matter of course 
Similar threads
