Blender Course
- Thread starter Steele
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
OK, I'm assuming that the 2x15 tx15/55 doubles are full with 230 and that they not going to be used for diving (or else why else would you mention them in the problem?).
First, the deco bottles:
Drain 26.6 bar from the 7L and top with air to 200 bar
Add 33 bar O2 to the 10L and top with air to 160 bar
If you want to get spiffy, you can transfill the 7L and 10L but, you'll still need to drain some and add more, but at least you're saving a little gas!
I looked at the two sets of doubles a few different ways-
1) drain, transfill, he top, o2 top, air top- you'll run out of O2
2) drain, transfill, o2 top, he top, air top- you'll run out of He
3) drain, he top, o2 top, air top- this MIGHT work, but you might run out of O2, and it doesn't use the gas in the 2x15's
So here is what I would do?
1) drain the tanks and drink beer- clean, VIP, as necessary
2) add 79 bar He
3) add 16 bar O2
4) transfill with the 2x15 to increase 45 bar in the doubles
5) air top with 90 bar
I did this quickly, so please check if this works. And don't forget to cascade the tanks!
First, the deco bottles:
Drain 26.6 bar from the 7L and top with air to 200 bar
Add 33 bar O2 to the 10L and top with air to 160 bar
If you want to get spiffy, you can transfill the 7L and 10L but, you'll still need to drain some and add more, but at least you're saving a little gas!
I looked at the two sets of doubles a few different ways-
1) drain, transfill, he top, o2 top, air top- you'll run out of O2
2) drain, transfill, o2 top, he top, air top- you'll run out of He
3) drain, he top, o2 top, air top- this MIGHT work, but you might run out of O2, and it doesn't use the gas in the 2x15's
So here is what I would do?
1) drain the tanks and drink beer- clean, VIP, as necessary
2) add 79 bar He
3) add 16 bar O2
4) transfill with the 2x15 to increase 45 bar in the doubles
5) air top with 90 bar
I did this quickly, so please check if this works. And don't forget to cascade the tanks!
pickens_46929
Contributor
Steele:Congrats on the pass! Yea, my class was 2 days long. (I think it depends on the instructor) Day one consisted of 6 hours of lecture and knowledge reviews, followed by 3 hours of practical work. We had 3 teams of 2-3 people in the class and we each were responsible for O2 cleaning a couple sets of tanks and valves the first day.
The second day lasted about 4-5 hours of more practical (hands-on) work as we continued O2 cleaning and cooking up 4-5 various types of mixes each. The day ended with the written test.
The course was so well taught, my retention of various formulae is still with me. Normally, I'd have forgotten it and relied on the computer to do the computations. Hell, I'm comfortable doing it long-hand and verifying it with the computer. (Yes, I'll verify - O2 and He can be expensive if you've screwed the pooch so bad you need to release several hundered psi out of the bottle)
The written test was the hardest part of the whole thing... the wording of the questions was tricky but still muddled through it. We used tables and the computer almost exclusively.
We did an argon fill, a trimix, a pure O2 and a nitrox fill I think.
Glad you had fun too!
knew and impruved!
I think we can save a little more helium. This one is close to the previous attempt, but uses more of the 15/55 mix and requires more beer.
1) drain tanks and drink beers
2) add 74 bar He
3) add 15 bar O2
4) transfer 54 bar into the two sets of doubles from the 2x15. After equalizing, the pressure will be 143 bar
5) air top with 87 bar
If you really want to get crazy, after transfillng the 15/55, you could air top the 2x15's and transfill again to get more out of them. You could also do unthinkable things with the isolator to use more of the helium, but that's just going too far.
I think we can save a little more helium. This one is close to the previous attempt, but uses more of the 15/55 mix and requires more beer.
1) drain tanks and drink beers
2) add 74 bar He
3) add 15 bar O2
4) transfer 54 bar into the two sets of doubles from the 2x15. After equalizing, the pressure will be 143 bar
5) air top with 87 bar
If you really want to get crazy, after transfillng the 15/55, you could air top the 2x15's and transfill again to get more out of them. You could also do unthinkable things with the isolator to use more of the helium, but that's just going too far.
As i wrote you - we are talking about 2x12s doubles. The blending preasure is 220 bar - so the final should be 200 bar.
Cheers
Mania
Cheers
Mania
OK I'm thoroughly confused now. I gotta quit the deep air diving. 
Just finished my DSAT Gas Blender certf. course for Nitrox/Trimix....was very good.
Similar threads
