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Diving with high pressure (DIN) steel tank

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Diving with high pressure (DIN) steel tank

Post Number:#1  Postby fun diver » Mon Mar 07, 2011 1:22 am

Could anybody share their experience or any tips on how to properly trim bouyancy using steel tank?
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Re: Diving with high pressure (DIN) steel tank

Post Number:#2  Postby Nizaha » Mon Mar 07, 2011 7:53 am

What size steel tank do you using? Most important diving with steel tank is Wing/lift. Do you using a drysuit?

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Equipment can go to those depths, but your body might not be able to..
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Re: Diving with high pressure (DIN) steel tank

Post Number:#3  Postby garthak » Mon Mar 07, 2011 1:11 pm

fun diver wrote:
Could anybody share their experience or any tips on how to properly trim bouyancy using steel tank?


Depends on a few factors really, Size of tank, buoyancy devise used and exposure suit. But basically Steel tanks are negative from start to finish.
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Re: Diving with high pressure (DIN) steel tank

Post Number:#4  Postby fun diver » Mon Mar 07, 2011 11:01 pm

i'm using 10 liter poseidon steel tank with wing bcd 50 pound lifting capacity (Poseidon Besea50). I'm not using dry suit or wetsuit, because the water is pretty warm 26 degree celcius. So i'm just wearing skinsuit. No weight use, only the steel tank.

i found it's a bit difficult to control my bouyancy underwater with steel tank compare to normal alluminium tank. Maybe because the weight (from steel tank) is only concentrated at the back, not distrubuted evenly. So if i tilt my body underwater, the weight push me down to one side. i have to force my self to tilt back to normal face down position.

And i also realize, it is easier for me to trim bouyancy by using heavy all rubber fins compare to normal light, sport fins when diving with steel tank. Because the weight of the steel tank push my body down, and light fins will lift my leg up too much and i feel not comfortable with this position. But heavy fins push my leg down and level with my body, results better trim underwater.

Maybe dear sifu2 in this forum can share their experince and some tips to dive with steel tank.
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Re: Diving with high pressure (DIN) steel tank

Post Number:#5  Postby fun diver » Tue Mar 08, 2011 4:33 am

Nizaha : i saw your video "Zaha Practice Dives", were you using double steel tank?
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Re: Diving with high pressure (DIN) steel tank

Post Number:#6  Postby Nizaha » Tue Mar 08, 2011 4:44 am

In Canada, I'm using double steel tank and  I do agree that stiffer fin way to go either diving with steel tank or Alu tank.. good speed, trim while swimming. Arching your spine/back give a little help to your trim.

Sometimes If you're using overkill size wing like(50lb),  Can mess you up big times in Buoyancy parts.. for single Steel/Alu  max lift you need is 30-40lb lift wing.. Technically speaking 50Lb Wing we use for double Aluminum or 100 HP steel double. I know diver around here using Steel tank 230Bar (13.2 L) ever bigger then your tank with 40lb with drysuit. You need to have backup lift in worst case especially diving with steel tank.,

May I ask you a question. You in warm water, Do they don`t have any Aluminum tank at all for you to use.!!  I won`t use Steel tank in skinsuit..(way to heavy,  ).. 10L =72 cu ft... rather use normal ALu 80cf.  IN my Honest opinion..

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Zaha
Last edited by Nizaha on Tue Mar 08, 2011 7:51 am, edited 1 time in total.
Equipment can go to those depths, but your body might not be able to..
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Re: Diving with high pressure (DIN) steel tank

Post Number:#7  Postby Nizaha » Tue Mar 08, 2011 4:48 am

fun diver wrote:Nizaha : i saw your video "Zaha Practice Dives", were you using double steel tank?



Yessir..

Double Steel 130 ..Heavy as hell.. almost 50kg with wet stuff..
Equipment can go to those depths, but your body might not be able to..
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Re: Diving with high pressure (DIN) steel tank

Post Number:#8  Postby fun diver » Tue Mar 08, 2011 5:38 am

Really appreciate your advice Zaha .Thank you.

I have 4 units normal aluminium tank myself.
Currently bought this 10L 300Bar steel tank. just wanna have the feeling diving with steel tank.. heavy but stable  and not positvely bouyant underwater even at 50 bar.

Yes, i agree with you. in warm water like here in Redsea, aluminium tank is a good choice.

Yes ,my wing lifting capacity 50lb is too much like you mentioned compare to my diverite wing 42lb (but this wing is in Malaysia right now).So i dont have much choice here.

With heavy steel tank at the back,  i think helicopter turn is the best instead of tilting my body to go other direction.
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Re: Diving with high pressure (DIN) steel tank

Post Number:#9  Postby aquaholic » Tue Mar 08, 2011 12:37 pm

Good to know you’re trying out new things.

IMHO, steel 232 bar or 300 bar tanks are good provided you can get fills to that pressure. The std fill here is 200 bar. Haven’t seen a 300 bar compressor amongst any of the dive operators yet, hence you won’t benefit from the potential extra volume of air.

The other thing is that you naturally tend to be negatively buoyant with steel throughout a wetsuit dive, hence the previous statement about ensuring back-up buoyancy.

I had a steel 15L 232 before
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Re: Diving with high pressure (DIN) steel tank

Post Number:#10  Postby fun diver » Tue Mar 08, 2011 3:10 pm

aquaholic : There is high pressure compressor here in KSA. The only high pressure compressor in the kingdom, up to 300bar/4300psi. No way to bring back this tank to Malaysia, too heavy for airport tax.. plus dont have high pressure compressor in Malaysia  ;)

btw, what do you mean by backup bouyancy?
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Re: Diving with high pressure (DIN) steel tank

Post Number:#11  Postby aquaholic » Tue Mar 08, 2011 4:12 pm

I stand corrected. Apparently you can adjust any compressor’s pressure relief valve to do 300 bar fills. Having said that, I’ve seen the state of compressors and filling whips whom I (maybe also the operator) will not dare to do >200 bar fills.

The failure scenario is you cannot inflate your BCD (inflator or orally) for whatever reason. Steel with wetsuit makes you negatively buoyant, which forces you to swim up (in the absence of a shot line) to ascent and then having to tread water to stay afloat. This can be exhausting towards the end of the dive, esp with choppy waves. This problem will be dangerous if you have to do mandatory mid-water deco stops.

Backup buoyancy can be thru inflating your drysuit, smb. Some smb has one-time use CO2 cartridges.

Bottom line, you can use whatever equipment but you need to be weighted correctly (or understand your contingency plan) – i.e. need to be slightly positively or neutral buoyant with empty bcd and empty tanks (simulating end of the dive condition), then add weights in order for you to comfortably do 3m or 6m deco stops. So if the brown stuff hits the fan just ditch the weights.

This leads to the common practice of : steel with drysuit, alu with wetsuit.
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Re: Diving with high pressure (DIN) steel tank

Post Number:#12  Postby fun diver » Tue Mar 08, 2011 4:21 pm

Thank you for sharing the advice and info aquaholic...
Really appreciate learning from  sifu2... ;)
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