Air compressor

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
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In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

In article <BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net>,
Mike Painter <mdotpainter@att.net> wrote:
>
>
>Our department will probably be getting a grant to buy a compressor within a
>year.
>Electric would be our choice and it will be used for up to the 4500 psia
>bottles.
>
>I'm looking for informed recommendations.
>
>Here's my main concern. This thing will *not* be used much. I can change
>filters, check levels and run the things but I need information on unit that
>may sit unused for months.
>
>Obviously a duty cycle can be arranged but is this needed?

How fast does it need to be?

I have an Alkin W31, and for a small unit, its the only one I'd consider.

Now if you need 5+cfm its not the right choice, and I'm not sure the W32 is
your best option in that class either. But for the smaller, 3cfm units, its
the ONLY unit on the market that I would buy and own.

--
--
Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist
http://www.denninger.net Tired of spam at your company? LOOK HERE!
http://childrens-justice.org Working for family and children's rights
http://diversunion.org LOG IN AND GET YOUR TANK STICKERS TODAY!
http://scubaforum.org Your UNCENSORED place to talk DIVING!

I don't know what brands are available in the US, however here in the UK,
the most popular & reliable of the smaller compressors (3.5 cfm/ 100L/min)
are the German made Bauer compressors and the Hamworthy (which was UK owned
but I now believe is US owned).

I have a second-hand UK made Hamworthy with a Honda 5.5Hp petrol engine, and
do approximately 60 -100 hours pumping annually on this unit with no
problems (it's only used for mine & my wife's cylinders).

Wherever possible I would use a fully synthetic compressor oil (use
manufacturers recommendation) and if it's attached to a petrol engine, then
the same care rules apply as for petrol lawnmowers (they are also often laid
up for several months at a time over winter), especially relating to old
petrol 'gumming' up in the carburettor, oil changing and spark plugs.

Keep the compressor air filter & housing clean & dry (after each session of
pumping I remove the filter housing & clean out all the condensed water &
oil vapour and re-lubricate the filter housing O rings).


As for larger compressors, there is a wide choice, both from the above two
makes and also other brands such as Dunlop and also the oil-free Rix brand
compressors which can be used to pump pre-mixed Nitrox (they use Teflon
'dry' bearings similarly to Haskell oxygen booster pumps). Different models
will have different specifications so don't assume that you can pump
anything but air unless it is specifically stated for that model.

On larger compressors you can also specify other details such as
auto-purging (all compressors need to purge the condensed water & oil that's
removed during the air compression) at regular intervals so it is not
squirted into your cylinders. Small compressors use a manual valve (often
just a screw in knob), but a timed system is much easier. I have to open a
valve every 20 minutes on mine.

I would also recommend using two filter stacks, one with the standard
multi-layered filter cartridge (the main components are Silica-gel
desiccant, molecular filtration granules and activated charcoal separated by
pads), followed by a second stack purely to remove any of the final
hydrocarbons (activated charcoal is cheap & perfect for this job), this then
gives air suitable for filling O2 clean (Nitrox) cylinders.

Finally, although fiddly & time consuming, you can save quite a bit of money
if you use re-fillable filter cartridges rather than the disposable
cartridges, that's your choice. I use disposables (they are rated on my
compressor for about 20 hours of filling). Larger compressors and larger
filter stacks may offer longer times between changing.

If you are buying new then you must specify exactly these details so you're
not disappointed when you get the unit.

1. How much filling you estimate you are going to be doing (including
topping off a reservoir bank) then multiply by at least 2.

2. how long you expect each filling session to last.

The above will determine the size in Cubic Foot per Minute (CFM) or Litres
Per Minute you will need. As a rule of thumb, 3.5CFM=100LPM so a 12 litre
Cylinder pumped to 200 BAR (3000psi) will take 24 minutes, roughly the same
as a 120 CuFt cylinder to 3000 PSI.

3. If you want Nitrox clean air then a second filter stack is required, and
the size of the stacks and compressor will determine their frequency of
changing.

4. What type of motor is required. petrol is most convenient & portable,
however its noisier, more expensive (at least here in the UK where unleaded
petrol is 83 pence per litre (about $6 per US gallon (4 litres)) and will
require more servicing. Electric motors are quieter, cheaper and almost
maintenance free, but an electrically powered compressor bigger than 5cfm
will almost certainly need a three phase electrical supply.

5. Any additional options, such as auto purge and what pressure the
compressor is set to (most can pump up to 300BAR / 4500 psi) but an
over-pressure valve should be fitted and can be set to 'blow off' at a
predefined pressure so you don't over fill and damage the cylinders.


Finally, you MUST keep a compressor log, especially if you are filling
commercially (in the UK it comes under the Health & Safety laws and you can
be inspected without warning), but even for personal use you should keep a
log of time & dates of filling, filter changes and servicing.

I hope this helps.

Tony


"Mike Painter" <mdotpainter@att.net> wrote in message
news:BKEpc.10638$hH.266231@bgtnsc04-news.ops.worldnet.att.net...
> Our department will probably be getting a grant to buy a compressor within
a
> year.
> Electric would be our choice and it will be used for up to the 4500 psia
> bottles.
>
> I'm looking for informed recommendations.
>
> Here's my main concern. This thing will *not* be used much. I can change
> filters, check levels and run the things but I need information on unit
that
> may sit unused for months.
>
> Obviously a duty cycle can be arranged but is this needed?
>
>