Mk25

[scubadada]

Whatever, I just purchased a 2012 MK25 DIN/S600 (for $425). It came with a package insert that said "Don't connect a R-series second stage or ocotpus to the central LP port in the first stages equipped with a swivel turrent since the axial-direct High Flow could make your R-series second stage not work properly". There is a clear picture illustrating the above. Got me. So what would you put here, your BC or drysuit inflator?

 

[elan]

. So what would you put here, your BC or drysuit inflator?

No, mount an A, G, D or S series second stage

 

[scubadada]

Of interest to me, I posted to the manufacturer's thread. Sorry, did not follow the comment regarding A, G, D, or S series regulators. Is this like R109 and S600?

 

[James R]

So what would you put here, your BC or drysuit inflator?

single tank diving: nothing

backmount doubles: right post inflator hose, left post bungee backup 2nd stage.

 

[halocline]

First off, I have absolutely no idea what the problem would be with connecting an unbalanced 2nd stage to the end port. That's what the "R" series 2nd stages are. Apparently it's fine to connect a balanced 2nd stage. What about an unbalanced barrel poppet 2nd like the G200 or 109? The "A, D, G, S" series are all balanced 2nd stages.

The difference between the end port and the side ports is that there is a different flow dynamic at that port because it is directly downstream of the piston shaft, meaning air comes out the piston shaft and could travel straight into the port. I could envision some strong venturi issues creating pressure drops in the other ports while air is blasting out the end port. But I don't see how an unbalanced 2nd stage makes any difference.

I love the end port for single tank diving, but I use a long hose and the routing out the end is fantastic with the turret pointed down and slightly to the diver's right.

 

[redacted]

What I read restricted the use of R-series reg, not unbalanced regs. Maybe Scubapro does not think the venturi controls on an R-series reg are capable of handling the somewhat increased flow rate (but a G200 will be OK). Or maybe it is just good advertising and sells more expensive 2nds.

 

[halocline]

The 'classic' DIR doubles set up is with two MK25s, at least that's what I've seen on the GUE website (I think). On the left post, the alternate 2nd stage is attached to the end port. DIR used to also prescribe unbalanced alternate 2nds. I suspect many of these were classic downstreams like the R190. Just a thought....

 

[elan]

I ran G250V , 156 and now run S600 as a backup on my DIR MK25 setup and never had any issues, all of them were tuned for max performance. I do recall having that note about R series regs in the box when I got MK25

 

[buddhasummer]

It's come up again...

Factory defective piston