Advice on new set up

[iain/hsm]

Continuous blending, as described above in the link, is by far the easiest and safest method to produce Nitrox up to EANx40..EDITED

Harry.

I’ m sorry but with respect, that’s utter rubbish. Your making clams of safety you cannot possibly hope to verify. In Europe any gas with a percentage of oxygen greater than 23% shall be classed as oxygen and oxygen is use no oil. What possible safety margin do you have banging out 40% through an oil lubricated air compressor?

To answer the OP question use the same analogy of cylinder working pressure to test pressure in order to achieve a safety margin.
Now you say: “Safe at 40%” then what percentage do you test it over that for safety? 70%……. 80% maybe? You get my point? If you manage a couple of points over 50% with an oil lube compressor without vaporising the place I will listen. I wont believe you but I will listen. Iain

 

[CraigAClark]

Harry.

I’ m sorry but with respect, that’s utter rubbish. Your making clams of safety you cannot possibly hope to verify. In Europe any gas with a percentage of oxygen greater than 23% shall be classed as oxygen and oxygen is use no oil. What possible safety margin do you have banging out 40% through an oil lubricated air compressor?

To answer the OP question use the same analogy of cylinder working pressure to test pressure in order to achieve a safety margin.
Now you say: “Safe at 40%” then what percentage do you test it over that for safety? 70%……. 80% maybe? You get my point? If you manage a couple of points over 50% with an oil lube compressor without vaporising the place I will listen. I wont believe you but I will listen. Iain

Then I guess the DNAx systems that I have installed on Lloyd's inspected vessels, which met their approval, aren't considered safe? I'll admit that I lean to water cooling, but they have approved both. None of the compressor manufacturers will "authorize" nitrox production with their machines here in the US, but it's strange that Bauer offers a membrane system out of Munich. Seems they consider nitrox production as safe with their machines, or are they just trying to get in on the market, no matter what?

Craig

 

[iain/hsm]

No disrespect intended, but no compressor in the world that is oil lubricated will produce breathable air/nitrox/trimix. The produced gas must go through a filtration system in order to reach standards for breathing gas. Craig

On that point we agree and in principle are saying the same thing. But once again the smoke and mirrors are out to confuse and mislead.

Therefore, if the compressor is already equipped with filtration to meet the EU standard, then nitrox production through the same filtration will meet those standards as well. As with any system, the gas produced will only be as good as the maintenance provided to that system.

No sorry Craig thats rubbish. We in EU must separate an air compressor specification from a nitrox or gas compressor specification they are two different animals. For air compressors the filtration requirement for “air compressors” in W Europe is to EN 12021 and with regard say to the oil particulate at the outlet the maximum allowed is 0.5 Mg/M3. This is achieved by using activated carbon or activated charcoal.

For gases other than air i.e. your Nitrox, Heliox, Trimix etc the filtration requirement is to EN 8478:2006 Breathing Gases. It’s a totally different standard and requirement. Now again same example taking the oil particulate the maximum level is now only 0.01 Mg/M3.

However our requrements also state that any gas with a percentage greater than 23% shall be class as oxygen and oxygen is “USE NO OIL” so the compressor used to compress nitrox is also different from one compressing air. It's oil-free and or oil-less and certified for that gas and pressure.

At a guess in the USA you guys compress oxygen and mixed gases in other industries apart from scuba diving, ever seen them use a condensate drain or chemical filter plant attached to or seen them using activated charcoal on an HP oxygen compressor in a hospital or oxygen gas supplier ? No, I think not.

It’s the same mechanical safety requirements in USA as it is in EU its just that IMHO your scuba “industry” (if I can call it that) is still "cobbling" both there production and safety making a total pigs ear of it. Its a joke.

I assure you that the systems I have built, membrane and PP Blending are not "cobbled" together. I believe, that if you do some research, you will find that the majority of deaths/sickness from "bad" gas are attributed to CO and not CO2. Craig

Craig again with repect not to you specifically as I dont know what you do but in the main what we see in Europe of most USA membranes you guys "build" in the States are from N2 membranes designed and manufactured over here in the Netherlands. These Permea membranes are in fact originally nitrogen membranes, you guys wire them up backwards and use the permeate and call it Nitrox.
IMHO Its a joke you are having a laugh.

In reply to your C02 content alone these membranes concentrate gas over the maximum allowed safety limit for breathing in Europe and that includes the Argon as well as the C02. They exceed the maximum requirement for C02 by over 100% and cannot achieve purity even under the relaxed breathing air standards (set at 500ppm)

Finally regarding CO we could both use the research, but my guess is that C0 is mostly caused by poor intake positioning, split or poorly fitting intake hoses when using petrol (gasoline) driven engines.

In the case of you guys pouring oxygen into your oil lubricated compressors, it is caused by the brakedown of the oil in the compressor in the first place, further compounded by some joker telling us they could run 40% oxygen through their compressor and its safe......... The oil burns down in the elevated nitrox concentration giving off these complex oil degrading compounds including C0.

Why the heck do you think these oil lube compressor boys have you change the oil out so often when using nitrox. What was once a 2000 hour oil change is now what 200 hours? 20 even if you listen to some posters.

There having a laugh, Safe my ass LOL Iain.

 

[iain/hsm]

Then I guess the DNAx systems that I have installed on Lloyd's inspected vessels, which met their approval, aren't considered safe? I'll admit that I lean to water cooling, but they have approved both. None of the compressor manufacturers will "authorize" nitrox production with their machines here in the US, but it's strange that Bauer offers a membrane system out of Munich. Seems they consider nitrox production as safe with their machines, or are they just trying to get in on the market, no matter what? Craig

Craig.
No don’t, not the Lloyds “approved” bull****. More smoke and mirrors.
Look you know as well as I these 3rd party QA inspection authorities will “approve” a kids balloon and call it a pressure vessel if that’s what you pay them to do.
Its what is called a Lloyds “Witness of Test”.

Don’t bull**** us with a Lloyds “Witness of Test” from that of a “Lloyds Category Approval”. There is a growing number of very pissed off yacht owners that find that there compressor fire damage is not covered by there insurers, and that the fire damage the compressors cause is greater than the cost to replace or that of Lloyds.

Now regarding this Bauer nitrox membrane system look again it is TUV approved not CE
and is only sold outside of the EU mostly into Egypt where purity and standards are lower to pretty much non existant. Try and use one in England or Ireland and see how long before trading standards is on your tail. They have the same high C02 levels as the Permea, and the same oil problems.

Better still ask them for a oil spectrographic analysis of the crancase vapour pressure. See what sparks you make!! LOL Iain

 

[Doc Harry]

Harry.

I’ m sorry but with respect, that’s utter rubbish. Your making clams of safety you cannot possibly hope to verify. In Europe any gas with a percentage of oxygen greater than 23% shall be classed as oxygen and oxygen is use no oil. What possible safety margin do you have banging out 40% through an oil lubricated air compressor?

To answer the OP question use the same analogy of cylinder working pressure to test pressure in order to achieve a safety margin.
Now you say: “Safe at 40%” then what percentage do you test it over that for safety? 70%……. 80% maybe? You get my point? If you manage a couple of points over 50% with an oil lube compressor without vaporising the place I will listen. I wont believe you but I will listen. Iain

Whatever the theoretical risks, in practical terms there is a long-established safety record of producing EANx40 via CB in the USA. It is a common and widespread practice here, and accidents (if they have ever happened) are extremely rare.

Come on across the pond and I'll show you how it's done.

 

[iain/hsm]

Doc

Interesting photo. In Europe we have what is called a Written Scheme of Examination and Test Document for compressor instalations and would have the following comments and issues with that set up if used in a dive shop for nitrox in Europe.

1. No high temp cut off device on the compressor.

2. Possible that the air intake is from inside room (high C02 would you believe LOL)

3. Compressor needs to be certified for both the gas and the pressure ( The Alkin compressor from Turkey you show is not nitrox approved)

4. No ported vents on the relief valves

5. Pump not secured to wall (no wheels)

6. Charging hose (whip) possibly too short if cylinders fall could they yank the fittings off the walls

7. No ported vent on the HP oxygen

8. No safety cut off solenoid devise on the oxygen connected to compressor electrical cut out

9. No bleed valve on filter intake (that I can see)

10. No non-return valve on filter intake (that I can see)

11. Filter bleed is possibly on the outlet side (wrong side) can’t drain the small amount of collected moisture at bottom of filter tower cartridge.

12. BPR does not have check valve on outlet (maybe on 4 branch panel cant see) also a 2Mu filter to protect from the chemical tower any filter material dust.

13. The 4 branch panel has ¼ turn Hoke valves, not suited for nitrox

14. The 4 branch panel allows both back flow and cross contamination from 2nd cylinder

15. Flexible hose from cylinders 3 off should be in hard tube. Whip injury need addressing

16. Flexible charging hoses should have safety wire hoop retainers and crimps

17. Output to high pressure storage cylinders wrong, can be contaminated by scuba cylinder needs to be separated from stored gas source.

18. Wall mounted hose retaining clamps poor quality not suitable for holding back hose in the event of a hose rupture.

19. No compressor emergency stop button or remote stop button (I can see)

20. Lets not go into American wiring standards or we will be here all night !! LOL

The written procedue also covers filling intructions SOP and the requirement for filter change outs and service. We are also required to show a certificate of in date air purity tests on the wall of the air or gas purity and also a certificate of test of the high pressure storage cylinders. I expect this is a bit different to what you guys think. LOL Iain

 

[Doc Harry]

Well, let's see if I can respond to your concerns.

First of all, I have to be physically present at all time for continuous blending, so I don't need safety cutoff switches, solenoids, etc., etc., because I am sitting right there. there is a very large ABC fire extinguisher just out of view near the exit.

No manufacturer will authorize their compressors for continuous blending here because we have these utterly nasty people here called "lawyers."

I run an industrial fan for both extra cooling and to keep the garage air flushed.

There are six bleed valves in strategic locations.

There is one-way valve where it is needed.

The first filter has two bleeds to drain water, the second has one moisture bleed, and the third filter tower doesn't need a water drain because by the time gas there it has a dew point of -90 degrees F and is plenty large enough to absorb any residual moisture.

There is a 2 micron filter downstream from the filters to filter dust.

Whips are plenty long enough.

The relief valves are ported.

You don't need a ported vent for the HP oxygen.

The manifold panel is designed to cross-flow since all 3 bank cylinders are treated as if they are in series not parallel. It was simpler to rig it this way than a true series.

The 1/4 valves are suitable for Nitrox but not 100% oxygen.

Yes, the flexible hose is an issue that I plan to address someday. Someday.. The hose is rated over 1,500 PSI higher than my highest pressures and that's a large enough margin that I don't worry about hose rupture and whipping.

An electrician wired both the electrical cord and the fuse box for me according to local standards.

Interesting thought about scuba cylinders contaminating the storage bank, I'll have a look at that.

I test my air twice a year through Analystical Chemists and the results are in those notebooks. I also test every cylinder for carbon monoxide after it is filled. So far the highest reading has been... zero ppm. My air greatly exceeds oxygen-compatible air standards in all categories.

Finally, as we say in the USA:

"I don't need no stinkin' Written Scheme of Examination and Test Document in my garage."

Doc

Interesting photo. In Europe we have what is called a Written Scheme of Examination and Test Document for compressor instalations and would have the following comments and issues with that set up if used in a dive shop for nitrox in Europe.

1. No high temp cut off device on the compressor.

2. Possible that the air intake is from inside room (high C02 would you believe LOL)

3. Compressor needs to be certified for both the gas and the pressure ( The Alkin compressor from Turkey you show is not nitrox approved)

4. No ported vents on the relief valves

5. Pump not secured to wall (no wheels)

6. Charging hose (whip) possibly too short if cylinders fall could they yank the fittings off the walls

7. No ported vent on the HP oxygen

8. No safety cut off solenoid devise on the oxygen connected to compressor electrical cut out

9. No bleed valve on filter intake (that I can see)

10. No non-return valve on filter intake (that I can see)

11. Filter bleed is possibly on the outlet side (wrong side) can’t drain the small amount of collected moisture at bottom of filter tower cartridge.

12. BPR does not have check valve on outlet (maybe on 4 branch panel cant see) also a 2Mu filter to protect from the chemical tower any filter material dust.

13. The 4 branch panel has ¼ turn Hoke valves, not suited for nitrox

14. The 4 branch panel allows both back flow and cross contamination from 2nd cylinder

15. Flexible hose from cylinders 3 off should be in hard tube. Whip injury need addressing

16. Flexible charging hoses should have safety wire hoop retainers and crimps

17. Output to high pressure storage cylinders wrong, can be contaminated by scuba cylinder needs to be separated from stored gas source.

18. Wall mounted hose retaining clamps poor quality not suitable for holding back hose in the event of a hose rupture.

19. No compressor emergency stop button or remote stop button (I can see)

20. Lets not go into American wiring standards or we will be here all night !! LOL

The written procedue also covers filling intructions SOP and the requirement for filter change outs and service. We are also required to show a certificate of in date air purity tests on the wall of the air or gas purity and also a certificate of test of the high pressure storage cylinders. I expect this is a bit different to what you guys think. LOL Iain

 

[iain/hsm]

Finally, as we say in the USA:

"I don't need no stinkin' Written Scheme of Examination and Test Document in my garage."

Hahaha I hear what your saying thats the great thing about being from the land of the free, We by contrast are still subjects to the Queen.

However the great thing about a simple “Compressor Written Scheme of Examination”, it is the ability for anyone however qualified or not, to have the tools to a full assessment of a compressor system without being mislead, misguided, or deceived.

The Written Scheme is not only useful in outlining the basic safety requirements of a compressor and its control system, however simple or indeed complex but also of being able to outline quickly and simply the basic safety areas of critical risk.

It can also be used as the basis of a system design tool or as a specification outline to component suppliers and compressor vendors such as the compressor manufacturers and as a defence to insurance carriers for reduced premiums and assured insurance claim payouts in the event of an accident or fire.

The Written Scheme is not the only document required in a compressor installation in Europe but it is used in addition with the various test certificates with other documents, one being a Safety Audit, the other more interesting being a Risk Assessment. Iain Middlebrook.

 

[Doc Harry]

I know that the Alkin W31 is not approved for Nitrox, but.... I just the air test results. The compressor has been in use for one year now. Before I performed my annual maintenance and filter changes, I decided get two air samples after warming up the compressor for one hour:

1) the raw compressor output
2) the air after it passed through the filters.

Both samples qualify as Grade E oxygen-compatible air.

So it is possible to mix your own Nitrox without having to spend $10,000 on a compressor.

 

[iain/hsm]

I know that the Alkin W31 is not approved for Nitrox, but.... I just the air test results. The compressor has been in use for one year now. Before I performed my annual maintenance and filter changes, I decided get two air samples after warming up the compressor for one hour:

1) the raw compressor output
2) the air after it passed through the filters.

Both samples qualify as Grade E oxygen-compatible air.

So it is possible to mix your own Nitrox without having to spend $10,000 on a compressor.

Harry.
You really think so? Just print out or PDF the test results of both of these tests and we shall see, shall we? Iain Middlebrook