Second stage flow rates-lack of data

[Greg Barlow]

Just out of interest, I checked a number of different manufacturer's sites to see if they listed the flow rates of their first and second stage models.

I was interested due to the past discussions about first stages delivering too much gas flow and leading to icing condtions in cold water. From my experience in working with reg designs, most "high perfomance" second stages can deliver a flow rate in the area of 70scfm, with "standard designs" going around 40scfm.

Does anyone know of any printed data sources that actually list the maximum flow rate through various second stages? My guess is that DA Aquamaster has some info on the various ScubaPro models.

Any links would be greatly appreciated.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine

 

[Diver0001]

The only empirical tests I know of are the flow tests Curt Bowen did.

1000 litres per min seems to be a good working number for a violent free-flow.

R..

 

[DA Aquamaster]

Scubapro lists flow rates for their second stages in the owners manuals.

X650 = 71 SCFM
S600 = 66 SCFM
D400 = 64 SCFM
S550 = 64 SCFM
G250HP = 57 SCFM
R190, R290, R380, R390 = 50 SCFM

They used have superb catalogs with cutaway drawings, explanations of how things worked, and performance numbers for all their first and second stages, but they stopped doing that sometime in the 90's.

 

[Greg Barlow]

They used have superb catalogs with cutaway drawings, explanations of how things worked, and performance numbers for all their first and second stages, but they stopped doing that sometime in the 90's.

[/QUOTE]

Thanks, DA. I have an old '92 ScubaPro catalogue that I was thumbing through after I posted my message. It does have some interesting info. Mares and Poseidon still provide the information on their websites, but the other manufacturer's don't seem as willing to do so.

Greg Barlow

 

[wb416]

Thanks, DA. I have an old '92 ScubaPro catalogue that I was thumbing through after I posted my message. It does have some interesting info. Mares and Poseidon still provide the information on their websites, but the other manufacturer's don't seem as willing to do so.

Greg Barlow

Hey Greg,
Long time no see! Been awhile since I've seen you at Gilboa. Are you still an administrator in the Cincy area?

Bob

 

[Greg Barlow]

Hey Greg,
Long time no see! Been awhile since I've seen you at Gilboa. Are you still an administrator in the Cincy area?

Bob

Hey, Bob!

Yes, I am still working in administration. I haven't been to Gilboa for quite some time. Mike used to be okay with letting me dive solo, but after the "accidents" he has become uneasy with anyone doing so. Most of my local dive buddies prefer to go to Blue Springs as it is much closer to home. I don't like the thought of driving up to Gilboa by myself and then asking other divers if they mind me diving with them. Now, if I knew you were going to be there on an open day....

I've also gotten my full cave certification, so I try to make at least two trips to Florida each year.

How is your diving coming along? Has Gilboa remained fairly busy through this past year?

Best Wishes,

Greg

 

[wb416]

Hey, Bob!

Yes, I am still working in administration. I haven't been to Gilboa for quite some time. Mike used to be okay with letting me dive solo, but after the "accidents" he has become uneasy with anyone doing so. Most of my local dive buddies prefer to go to Blue Springs as it is much closer to home. I don't like the thought of driving up to Gilboa by myself and then asking other divers if they mind me diving with them. Now, if I knew you were going to be there on an open day....

I've also gotten my full cave certification, so I try to make at least two trips to Florida each year.

How is your diving coming along? Has Gilboa remained fairly busy through this past year?

Best Wishes,

Greg

I was just at Gilboa this past weekend, and when we arrived, the only other people diving was parked and diving the deep end in a single tank and pony bottle. So Mike must be willing to let people dive solo under at least certain circumstances.

I've gotten my full cave and normoxic mix certs since I met you last, so I try to get down to the caves when I can also.

Most of my diving this year was "outside" of quarries (caves, wrecks, and reefs), so I'm not sure how busy Gilboa was on a consistent basis, but they seemed crowded during the summer when I stopped in.

It would be good to get together again sometime.

bob

 

[Greg Barlow]

Most of my diving this year was "outside" of quarries (caves, wrecks, and reefs), so I'm not sure how busy Gilboa was on a consistent basis, but they seemed crowded during the summer when I stopped in.

It would be good to get together again sometime.

bob

[/QUOTE]

My diving is very similar to yours. I figure if I am going to dive a quarry it might as well be close to home. Being in Southern Ohio I would rather dive in a quarry than count the days to my next dive trip. Blue Springs had a measured vis of 30' last Friday. The vis was consistent from surface to the bottom. Of course, the water was also a consistent 36 degrees!

Greg