First reg, need to buy two, rec diver

[cerich]

At least they had air during the polaris launch.

naw, they mostly spit their bad breathing reg out

 

[Akimbo]

naw, they mostly spit their bad breathing reg out

And them you discover that it's not the regulator at all, it's the fact that they are 150 Lbs overweight and haven't swam farther than their couch to their refrigerator in decades.

 

[cerich]

And them you discover that it's not the regulator at all, it's the fact that they are 150 Lbs overweight and haven't swam farther than their couch to their refrigerator in decades.

actually often it was a sherwood brut that had a corroded dry air element, a almost shut tank valve or anxiety.

 

[Bob DBF]

I actually am thankful I grew up using unbalanced regs and, by today's standards, poor performing regs. As @Akimbo said, the unbalanced regs are a great tool for determining tank pressure, especially with no SPG or j-valve. The other benefit is that when a reg starts performing poorly now, as I can troubleshoot the issue rather than think I'm not getting enough air and panic.

I am not of the mind that a poor breathing reg will help lower your gas consumption, as I was told when the balanced regs came on the scene. But it is good to know that I don't need nearly as much air as I am provided by modern regs. It may never come in handy for most, but I've used it.


Bob

 

[Akimbo]

I am not of the mind that a poor breathing reg will help lower your gas consumption, as I was told when the balanced regs came on the scene.

Actually a high performance regulator will slightly lower gas consumption because CO2 stimulates breathing. However, high performance isn't limited to balanced first and second stages. Take the Kirby Morgan second stages tested to 1,600'/487M for example. Hook that up to a 3/8"/9.5mm ID hose and fed by a 1/2" industrial Tescom single stage unbalanced regulator and you will out-perform any Scuba regulator on the market. Big holes = high flow.

Like I wrote and you know well, balanced second stages allow smaller diaphragms which allows smaller regulator bodies hanging from your mouth. They are also more tolerant of first stage IP pressure drift. Any idiot can design a regulator that performs great if the diaphragm was the size of a manhole cover.

 

[cerich]

Actually a high performance regulator will slightly lower gas consumption because CO2 stimulates breathing. However, high performance isn't limited to balanced first and second stages. Take the Kirby Morgan second stages tested to 1,600'/487M for example. Hook that up to a 3/8"/9.5mm ID hose and fed by a 1/2" industrial Tescom single stage unbalanced regulator and you will out-perform any Scuba regulator on the market. Big holes = high flow.

Like I wrote and you know well, balanced second stages allow smaller diaphragms which allows smaller regulator bodies hanging from your mouth. They are also more tolerant of first stage IP pressure drift. Any idiot can design a regulator that performs great if the diaphragm was the size of a manhole cover.

indeed

 

[halocline]

while I would agree that no new diver "needs" a titanium reg, why shouldn't they have one if they want?

There's nothing wrong with new divers buying very expensive regulators; my objection is when shops certifying students then use their authority as instructors to push students to buy high end gear that they don't need and that doesn't actually impact their diving in any significant way. Instructors should act as advocates for the students, and when a shop pressures them to act as de-facto gear salesmen, it's not usually in the nest interest of the student.

How this plays out is of course dependent on the culture of the shop. But the gear companies have a role in it too.

 

[halocline]

Like I wrote and you know well, balanced second stages allow smaller diaphragms which allows smaller regulator bodies hanging from your mouth.

How is this? I agree with the part about being more tolerant of IP shifts, but the geometry of diaphragm/lever/poppet shouldn't be related to whether or not the valve is balanced.

 

[Akimbo]

How is this? I agree with the part about being more tolerant of IP shifts, but the geometry of diaphragm/lever/poppet shouldn't be related to whether or not the valve is balanced.

A design characteristic of balanced second stage regulators allows shifting some of the counterforce of the mechanical spring holding the seat closed to the counterbalancing pneumatic "spring". That translates to a less force required on the lever so the diaphragm area can be reduced. That doesn’t mean that a diaphragm must be smaller, but most are. It is literally a design balancing act... pun intended. Compare the size of an old metal-body Conshelf to a new Legend for example.

Edit: @Luis H is one of the regulator gurus on Scubaboard, he can probably explain it far better.

 

[tbone1004]

Are there many unbalanced sets in current/recent production? The main one I know is the Mk2/R195.

A more complete list that I know is:
1st: SP MK2 piston, Aqualung Calypso piston, Edge Nano piston, Poseidon Cyklon 300 diaphragm, DA Aqua Master double hose.
2nd: ScubaPro R195, Aqualung Calypso, Edge Nano, Kirby-Morgan Superflow 350

Poseidon has not produced an unbalanced second stage in a VERY long time, like 1970's long time.

Poseidon to my knowledge has never made a balanced second stage