DIR- Generic "DIR Approved" Regulators

[PfcAJ]

Not that I’m a puker, but it seems plain oatmeal and scrambled eggs would be better puking material than say introducing some chunks of Louisiana Hot Links into the mix, or Chorizo.

Why fart it and waste it when you can burp it and taste it?

 

[Nick_Radov]

Are you trying to conform to GUE’s standards or do you want to be DIR?

If the latter, I recommend having a balanced adjustable primary that you can disassemble and an unbalanced backup that you can disassemble.

DIR doesn't necessarily require unbalanced backup second stage regulators. Let's take a step back and explain the reasoning here. The actual requirement is that the backup reg can't lose gas when it gets hit by scooter prop wash or strong current (like when squeezing through a restriction in a high flow cave). When water flows past the mouthpiece then the induced pressure differential can exceed the cracking pressure. If your backup reg slowly free flows, then it's easy to lose a lot of gas without noticing. Back in the early days of DIR, unbalanced regs like the ScubaPro R190 were popular for that purpose because they were cheap and unlikely to free flow. But balanced second stages can be fine, too, as long as they can be tuned to not leak. Just test it out by sticking the reg with the mouthpiece pointing up directly behind a running scooter and see if any bubbles come out.

I HAVE had to take a reg apart under water when a shell or a stick (this was quite some time ago) got stuck in the exhaust valve. It was easy peasy to clear it and finish my dive.

The notion of disassembling a reg underwater to clear debris is more of an advanced cave diving skill and not something that should be recommended to the majority of DIR divers. Cave divers squeezing through tight passages have their regs down in the muck where it's easy to pick up a rock or shell. And they may have a long way to go before switching to a stage. Whereas with ocean diving the problem is less likely to occur in the first place, and if it does then it's usually better to just abort the dive rather than risk losing pieces of your reg in a botched underwater repair. Taking the reg apart underwater can work and I've seen it done successfully but anyone considering doing this on a real dive should at least practice it in the pool a few times. Personally, I wouldn't try it.

A700 is a fine reg. G250 (and probably g260, no personal experience) is better for the above reasons.

Yes, I have used G260 as both a primary and backup. Works fine. You can turn back the adjustment knobs on the backup to reduce the risk of free flows.

 

[PfcAJ]

DIR doesn't necessarily require unbalanced backup second stage regulators. Let's take a step back and explain the reasoning here. The actual requirement is that the backup reg can't lose gas when it gets hit by scooter prop wash or strong current (like when squeezing through a restriction in a high flow cave). When water flows past the mouthpiece then the induced pressure differential can exceed the cracking pressure. If your backup reg slowly free flows, then it's easy to lose a lot of gas without noticing. Back in the early days of DIR, unbalanced regs like the ScubaPro R190 were popular for that purpose because they were cheap and unlikely to free flow. But balanced second stages can be fine, too, as long as they can be tuned to not leak. Just test it out by sticking the reg with the mouthpiece pointing up directly behind a running scooter and see if any bubbles come out.

The notion of disassembling a reg underwater to clear debris is more of an advanced cave diving skill and not something that should be recommended to the majority of DIR divers. Cave divers squeezing through tight passages have their regs down in the muck where it's easy to pick up a rock or shell. And they may have a long way to go before switching to a stage. Whereas with ocean diving the problem is less likely to occur in the first place, and if it does then it's usually better to just abort the dive rather than risk losing pieces of your reg in a botched underwater repair. Taking the reg apart underwater can work and I've seen it done successfully but anyone considering doing this on a real dive should at least practice it in the pool a few times. Personally, I wouldn't try it.

Yes, I have used G260 as both a primary and backup. Works fine. You can turn back the adjustment knobs on the backup to reduce the risk of free flows.

It’s not an advanced cave diving skill. You can get a stick in there on a shore entry just as easy.

Unbalanced regs have less parts, less sealing surfaces, and are more reliable. Reliability is what you need in a backup.

Turning the adjustment know down inevitably results in premature wear on the reg. 99% of the people I see with balanced backups leave that thing cranked down and when they opening it up, it free flows a bit (or a lot).

 

[Lorenzoid]

The notion of disassembling a reg underwater to clear debris is more of an advanced cave diving skill and not something that should be recommended to the majority of DIR divers.

I would just add here for the OP's benefit that disassembling a reg underwater to clear debris is not something that is mentioned in Cave 1 or Cave 2. I have disassembled my HOGs to service them, and I suppose I would be comfortable doing it underwater, but not having been taught the pros and cons, I don't think I would attempt it.

 

[OMyMyOHellYes]

If you want to disassemble the G260 underwater, you will want to remove the cover locking pin.

Oh, that got lost the first time I took the cover off and as SP won't sell parts ..... I guess I'll just have to go without.

 

[Eric Sedletzky]

Oh, that got lost the first time I took the cover off and as SP won't sell parts ..... I guess I'll just have to go without.

And if they did sell to the public that pin would probably be a $45 part.
You don’t need no stinkin pin.

 

[Nick_Radov]

It’s not an advanced cave diving skill. You can get a stick in there on a shore entry just as easy.

Sure, that can happen. But since it's never happened to me in over 20 years of shore diving, often at some fairly rough sites, I just don't think this is a common failure mode. The point is that this is way down on the list of issues for DIR divers to worry about, and underwater reg disassembly gets talked about online way more than done in real diving.

Unbalanced regs have less parts, less sealing surfaces, and are more reliable. Reliability is what you need in a backup.

Turning the adjustment know down inevitably results in premature wear on the reg. 99% of the people I see with balanced backups leave that thing cranked down and when they opening it up, it free flows a bit (or a lot).

I have never seen that happen with properly maintained Apeks or Scubapro balanced second stages. So again this seems like more of a theoretical issue rather than something that impacts real world diving. But I guess unbalanced regs may tolerate lack of maintenance or rough usage a little better.

 

[PfcAJ]

Sure, that can happen. But since it's never happened to me in over 20 years of shore diving, often at some fairly rough sites, I just don't think this is a common failure mode. The point is that this is way down on the list of issues for DIR divers to worry about, and underwater reg disassembly gets talked about online way more than done in real diving.

I have never seen that happen with properly maintained Apeks or Scubapro balanced second stages. So again this seems like more of a theoretical issue rather than something that impacts real world diving. But I guess unbalanced regs may tolerate lack of maintenance or rough usage a little better.

I’m glad that hasn’t happened to you. I haven’t had to do a lot of thing re: emergency diving problems, but I still train and maintain my equipment config in such a way as to be able to manage them should they occur.

Are we talking about DIR or are we just saying “meh close enough”? You can do whatever you want, but DIR is unbalanced. If you want to accept the shortcomings that come with balanced all around, that’s fine, but understand that you’re introducing potential for problems that don’t need to be.

Here’s an example: A maintained g250 poppet broke mid-stem. That just doesn’t exist with an r190 type 2nd. This is just an example of what can go sideways with balanced regs. On my BACKUP reg, the thing I need to work most, I want it to have the best possibility of working.

 

[lexvil]

I’m glad that hasn’t happened to you. I haven’t had to do a lot of thing re: emergency diving problems, but I still train and maintain my equipment config in such a way as to be able to manage them should they occur.

Are we talking about DIR or are we just saying “meh close enough”? You can do whatever you want, but DIR is unbalanced. If you want to accept the shortcomings that come with balanced all around, that’s fine, but understand that you’re introducing potential for problems that don’t need to be.

Here’s an example: A maintained g250 poppet broke mid-stem. That just doesn’t exist with an r190 type 2nd. This is just an example of what can go sideways with balanced regs. On my BACKUP reg, the thing I need to work most, I want it to have the best possibility of working.

Not to get into the dogma of this but I would love to know more about how this break happened since there are a lot of these balanced regulators out there the this hasn’t happened to.

 

[Nick_Radov]

Are we talking about DIR or are we just saying “meh close enough”? You can do whatever you want, but DIR is unbalanced. If you want to accept the shortcomings that come with balanced all around, that’s fine, but understand that you’re introducing potential for problems that don’t need to be.

We are talking about DIR. You can believe what you like, but DIR doesn't necessarily require unbalanced second stage regulators. I have that straight from the horse's mouth, so to speak.