Helium Purities

aquaxel

HI FOLKS, FOLLOWING ENQUIRY IF ANYONE PLEASE CAN HELP WITH IT:

DOING MOST DIVES IN CYPRUS (EAST MEDITERRANEAN) WE USE HELIUM GENERALLY CALLED HIGH PURITY HELIUM. IT WAS RECOMMENDED TO ME TO ALWAYS USE HELIUM 5 WHICH IS 99.999 GRADE. AS U CAN SEE BELOW FROM THE LINDE TABLE THERE ARE 2 PURITIES (5.0 AND ECD) OF 99.999 AVAILABLE.

THE GAS IS DELIVERED IN 50 LITRE TANKS AT 200 BAR AND COSTS ABOUT US520$ PER TANK.

LINDE HELIUM GAS SPECSHELIUM ECDHELIUM 5.0HELIUM 5.3HELIUM 5.6HELIUM 4.6HELIUM 6.0HELIUM 7.0PURITY>99,999>99,999>99,9993>99,9996>99,996>99,9999>99,99999PPM O2<2<2<1<0,7<5<0,5<30PPM N2-<3<2<1<20<0,5<30PPM H2O<2<3<2<1<5<0,5<50PPM CNHM<0.1<0,2<0.1<0,1<1<0.1<30PPM CO-----<0.1<30PPM CO2-----<0.1<30CERTIFICATEYNYYNYY

IN THE LATEST US NAVY DIVER MANUAL IT SAYS THEY USE HELIUM 99.997:

Table 4-4. Diver's Compressed Helium Breathing Purity Requirements.


Constituent Specification



Helium (percent by volume) 99.997%

Moisture (water vapor) 7 ppm (max)

Dew Point (not greater than) -78°F

Hydrocarbons (as Methane) 1 ppm (max)

Oxygen 3 ppm (max)

Nitrogen + Argon 5 ppm (max)

Neon 23 ppm (max)

Hydrogen 1 ppm (max)

Reference: Military Specification MIL-PRF-27407B

99.997 IS OF COURSE LESS PURE THEN 99.999 AND THEREFORE CONSIDERABLY CHEAPER HERE.

BESIDES THAT HIGHER PURITY IS OF COURSE ALWAYS BETTER BUT IF 99.997 DOES THE JOB FOR MUCH LESS COST THEN WHY NOT.

IF ANYONE OUT THERE COULD TELL ME WHAT YOU ARE USING AND BASED ON WHAT REASON THAT INFO WOULD BE HELPFULL.

THX + RGDS AQUAXEL
www.aquatec-innerspace.com

Mdemon

I'd like to second that question.

I checked with Air Products here in the UK and they have several grades of helium - ranging from the highest purity BIB stuff down to electrical grade. These have purity details and show in ppb what extra you can expect. BUT! They also do a technical grade, with no purity details, which sounds very similar to what is described above.

Has anyone used this grade? I use the industrial O2 without problems...

__________________
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"small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!"

The WRONG Attitude will get you killed.

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aquaxel

sorry i messed up the table - mayb thats better now

LINDE HELIUM GAS SPECS

HELIUM ECD
PURITY >99,999
PPM O2 <2

PPM N2 -

PPM H2O <2

PPM CNHM <0.1

PPM CO -

PPM CO2 -

CERTIFICATE y



HELIUM 5.0

PURITY >99.999

PPM O2 <2

PPM N2 <3

PPM H2O <3

PPM CNHM <0.2

PPM CO -

PPM CO2 -

CERTIFICATE n



HELIUM 5.3

PURITY >99.9993

PPM O2 <1

PPM N2 <2

PPM H2O <2

PPM CNHM <0.1

PPM CO -

PPM CO2 -

CERTIFICATE y



HELIUM 5.6

PURITY >99.9996

PPM O2 <0.7

PPM N2 <1

PPM H2O <1

PPM CNHM <0.1

PPM CO -

PPM CO2 -

CERTIFICATE y



HELIUM 4.6

PURITY >99.996

PPM O2 <5

PPM N2 <20

PPM H2O <5

PPM CNHM <1

PPM CO -

PPM CO2 -

CERTIFICATE n



HELIUM 6.0

PURITY >99.9999

PPM O2 <0.5

PPM N2 <0.5

PPM H2O <0.5

PPM CNHM <0.1

PPM CO <0.1

PPM CO2 <0.1

CERTIFICATE y



HELIUM 7.0
PURITY >99.99999

PPM O2 <30

PPM N2 <30

PPM H2O <50

PPM CNHM <30

PPM CO <30

PPM CO2 <30

CERTIFICATE y

rgds aquaxel
www.aquatec-innerspace.com

Phil

Hi,

I have been using HE 4.6 here in Switzerland for many years and no issues to report. I am not too concerned by the degree of purity in terms of content of helium but more in terms of germs, oil, etc... you never know where the 50L has been before and how did they used it. I am using the same booster for pumping HE & O2 and obviously my concern are on the hydrocarbon since I do not want to contaminate it. I do use a set of filter when pumping HE but still!

My 2 cents,

__________________
Phil
__________________
CCR/OC Instructor
CCR Training to Mixed Gas in Switzerland, France, UK & Germany on
Megalodon/KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel

www.zerogravitydiving.com

Triton

I use Balloon Helium and welding oxygen

Our Baloon He is Lab grade

Welding O2 is okay and always pure 99.8 otherwise it wont be good for welding ... and the dive shops


rgds

p.s The difference between the grades you mention would be equivalent to pumping a tank and having someone fart at the compressor inlet !

jradomski

In most places balloon bottles are just topped off/filled, the bottles are not vacuumed so ANYTHING can be present..

Typically the lower grades of He have hydrocarbon contamination (not good if you are using one booster pump). Co and CO2 are also not tested for in the lower grades.. A little co or co2 (for oc divers) can be deadly.. If you insist on using low helium grades please run them through the proper filtration ( a single cartridge should do).. some 13x and hopcalite would do nicely to remove most of the objectionalble stuff..

also in SOME areas oxygen is added to balloon helium for safety.

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

Triton

Well we only get one HE here and its lab grade(the purest)
If you ask it for baloons you pay alot.
If you ask it for lab you pay 4 times alot !!

The welding o2 is the same like medical.
The tanks are not vacumed but emptied.My scuba tanks are also not vacuumed.

In any case I could only have med tanks if I get someones grandma to fill in a paper.



But come now...a difference of .003 % is negligble impurites in real life....o no?
There exists no pure element in a bottle.