Selecting a booster for twin 12's and hot stages

[japandiver]

Advise on selecting a booster pump for twin12's and hot stages please....

I am currently living, diving and PP blending in Japan where O2 is only supplied at 140bar and, to make it worse, my supply of 47l J's is about to close. Soon, all I'm going to be able to get is 25l 140bar O2 or twin 12's at 200 bar with 80%.

I run my own compressor and am only looking to mix upto two twin-sets a week and upto 4 stages. My concern is that something like a jetsam baby booster will not be big enough but that a standard Haskel is too big / expensive.

Any suggestions on either a spec or suggested model for booster to be used by an OC twin-set & stages diver would be appreciated.

thanks

Hugh

[colinicky]

Well unless you have a lot of time then the small boosters ( jetsam baby booster, haskel sport booster etc ) aren't going to do it IMHO ,Some of us are waiting to see reports of this one New Booster In Town!!! - Rebreather World

the compression ratio is very good & the fact it will boost with only 7 bar drive gas pressure means that hopefully it will be very easy to run from a small oil free compressor .
HTH

[fatone]

Hi Hugh,
If you are for instance using a 7 l stage of 80% (149 bar O2 if filled to 200B)
consider using a larger stage 10 or 12 but at a lower pressure thus requiring lower O2 pressure ?

[colinicky]

Originally Posted by fatone

Hi Hugh,
If you are for instance using a 7 l stage of 80% (149 bar O2 if filled to 200B)
consider using a larger stage 10 or 12 but at a lower pressure thus requiring lower O2 pressure ?

The amount of PRESSURE of O2 required will be the same in any size cylinder for a given % it will be the amount of LITRES of O2 that differs .

ie :- 7L x 149 bar = 1043 Litres

10L x 149bar = 1490Litres

12L x 149 bar = 1788Litres

all of the above would give 80% at 200bar

If you lowered the fill pressure to give the same amount of Litres it may save a little but not noticable IMHO

[al kennedy]

.

[PW1664]

Originally Posted by colinicky

The amount of PRESSURE of O2 required will be the same in any size cylinder for a given % it will be the amount of LITRES of O2 that differs .

ie :- 7L x 149 bar = 1043 Litres

10L x 149bar = 1490Litres

12L x 149 bar = 1788Litres

all of the above would give 80% at 200bar

If you lowered the fill pressure to give the same amount of Litres it may save a little but not noticable IMHO

I think he was suggesting that the larger Cylinder could be filled to a lower pressure giving the same number of litres as the 7L, therefore not needing to boost the O2 so high..... if I read it right...

[colinicky]

Originally Posted by PW1664

I think he was suggesting that the larger Cylinder could be filled to a lower pressure giving the same number of litres as the 7L, therefore not needing to boost the O2 so high..... if I read it right...

That was why the last sentence was there

[Hazel W]

divetech (stanstead fluid power) midi booster DTB5C is quite good .....a bit bigger than a baby booster and fairly robust. used one on the boat all last season and proved to be up to the task. here: Gas booster - DTB5C




Hazel

[japandiver]

Thanks for the comments ... Colin the new no-name Asian brand might be interesting (in a good or bad way)... but a 60:1 compression ratio on an unknown booster would worry me when I'm boosting O2 in the shed!

Helen - thanks for the vote for the Stansted Fluid Power - they were / are the direction I am leaning.

The only upside to losing access to my J's of O2 is that I'm going to be drinking more beer while listening to the whoomp whoomp of the booster!

Thanks

Hugh

[NeilB]

Assuming you are mixing nitrox have you thought about a nitrox stick instead of partial pressure blending?