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fish(at)aviation-tech.com
Guest

Posted: Wed Jan 04, 2006 1:41 am Post subject: Air bottles



Yak List,

Over the weekend I was watching the Myth Busters, and they did a show on the

movie JAWS. One of the things they did was to shoot a hole in a Scuba bottle,

and the results were very interesting. The bottle did not blow up, but did have

to expend a serious amout of pressure(bounce all over a 40' sea container).

They stated the equivilant in explosives, but I do not remember.

Be carfull

John Fischer

Yak-52, N213YA

gus.fraser(at)gs.com
Guest

Posted: Wed Jan 04, 2006 5:53 am Post subject: Air bottles



No problem and I will throw in a Cuban at OSH 

Gus

rvfltd(at)televar.com
Guest

Posted: Wed Jan 04, 2006 6:40 am Post subject: Air bottles



Walt,

Page 107 of the Maint and Tech Specifications for the CJ6 states that the

tank is 8 liters. But now that you mention 12 liters I went to the PT-6

Trainer Aircraft Overhaul Manual for Airframe Accessories and find that it

calls out 12 liters. Who is buying the beer? I'm getting a sinking feeling

that it's me.

But Walt is correct on one point for sure, proceed VERY carefully, you are

dealing with a bomb.

Always Yakin,

Doug Sapp

brian-yak(at)lloyd.com
Guest

Posted: Wed Jan 04, 2006 7:59 am Post subject: Air bottles



doug sapp wrote:

 	  Quote: 	
		   What exactly is Boyles law?

	


P1*V1 = P2*V2

P = pressure

V = volume

For example: if you start with a 1 litre bottle with 100 kg/cm2 and then

let that expand into a 10 litre bottle, the final pressure will be 10

Kg/cm2. This assumes that the temperature and total amount of gas

remains constant.

It is a specific application of the more general formula for the ideal

gas law of:

PV = nRT

where:

P = pressure

V = volume

n = number of moles of a gas (based on Avogadro's constant -- actually

the number of molecules of the gas present in the container)

R = the universal gas law constant (0.0821 liter-atm / mol-K)

T = absolute temperature in degrees Kelvin (0C = 273K)

This latter formula will allow you to do calculations where the

temperature changes or the amount of gas present changes. If you want to

know what temperature will do to the pressure of the gas, you can

calculate it with this formula.

--

Brian Lloyd 2243 Cattle Dr.

brian-yak at lloyd dot com Folsom, CA 95630

+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .

- Antoine de Saint-Exupery

wlannon(at)cablerocket.co
Guest

Posted: Wed Jan 04, 2006 9:24 am Post subject: Air bottles



Hey Doug;

We must have different Tech. Specs. manuals. Pg 107 does not mention air

tanks. That is on pg. 109 and shows 12 liters.

Cheers;

Walt

L39parts(at)hotmail.com
Guest

Posted: Sun Jan 08, 2006 8:05 am Post subject: Air bottles



In the US, firemen's SCBA bottle fittings vary with the manufacturer. SCUBA

diving bottles use a standard fitting, but there are a lot of airports in

the US that are a long ways from the ocean and quite possibly a long ways

from a dive shop. Another problem is that most US airports don't have a

fire department on the field.

BasiliereR(at)ci.boulder.
Guest

Posted: Mon Jan 09, 2006 8:58 am Post subject: Air bottles



FYI on the firefighter SCBA fittings.  They are "all" standard GCA Universal threaded fittings.  Survivair, Scott, MSA, all the same.  If we have a big "event" multiple agencies will be "invited" and we need to be able to fill our bottles from other Fire Dept compressors or cascade systems.  I'd love to have the SCBA adapter to Russian airplane - the SCBA bottles are a dime a dozen.

 

Respectfully, rick b

 	  Quote: 	
		  >> L39parts(at)hotmail.com 1/8/2006 8:05:27 AM >>>

	


In the US, firemen's SCBA bottle fittings vary with the manufacturer.  SCUBA

diving bottles use a standard fitting, but there are a lot of airports in

the US that are a long ways from the ocean and quite possibly a long ways

from a dive shop.  Another problem is that most US airports don't have a

fire department on the field.

L39parts(at)hotmail.com
Guest

Posted: Mon Jan 09, 2006 11:51 am Post subject: Air bottles



SCUBA to commie airplane adapters can be ordered from my  former partner at  L39ZAparts(at)hotmail.com (L39ZAparts(at)hotmail.com) unless the Kazakistan warrants caught up with him.

 

I defer to your experience, which is probably more recent than mine.  In the mining industry, NIOSH allows only certified systems.  Our safety engineers determined that using a part (cylinder) from MSA on a regulator from Scott constituted an uncertified "system".  They were fanatics about things like that, not like FAA un-approved parts regs. 

 

At another job, we changed from Scott to a German-built system, Interspiro perhaps.  My recollection is that those fittings were incompatible with the existing filling fittings, but I wouldn't swear to it.  It was many years ago.

fish(at)aviation-tech.com
Guest

Posted: Mon Jan 09, 2006 12:56 pm Post subject: Air bottles



Yaksters,

I can not beleive that a fire dept, will allow there cylinder to connect to

your system. This is dangerous!

Once the pressure equilizes, the air can possably backflow into there tanks.

at this point there tanks are contaminated, and cannot be used for breathing

air until they are checked and cleaned. That is why you leave some pressure

in cylinders to keep them from becoming contaminated.

I would also have some concern about filling tanks at a shop as the same thing

can happen to their systems. Once the pressure equilizes form their tanks to

yours, there system will become contaminated.

I have heard to many stories about divers who had problems with thier air air

(compressors need to be maintained also), which sometimes leads to contaminated

air. That I would be rather error on the side of safety when it comes to breating

air (compressed or Oxygen).

Fly Safe

John fischer

BasiliereR(at)ci.boulder.
Guest

Posted: Mon Jan 09, 2006 12:56 pm Post subject: Air bottles



Absolutely correct on the "system" thing.?

?

Scott won't fit in a Survivair pac, nor will Interspiro, MSA, etc.?but...they (the bottles) can all fill from the same hose - that is the threaded GCA adapter on them all.? The new Scott NexGen2's are too cool.? They have their own specialized fitting to allow the bottle to "snap" into place (supplying high pressure air - 4500psi- to the first stage regulator) rather than being threaded on to the 1st stage like the others and the older Scotts (using the CGA?fitting).? The new Scott bottles have 3 different ways to fill them now - including the universal GCA.? Thank you Homeland Security for the 50 Scott packs we received (at)$4,000 a pop last week.? Good bye, Survivair and Monsieur Cousteau... (the dime a dozen used SCBA bottles alluded to earlier)

?

More than most of you folks cared to know about how our Firefighters go to work...sorry

?

Rick b???

dabear(at)damned.org
Guest

Posted: Mon Jan 09, 2006 1:01 pm Post subject: Air bottles



I've used my SCUBA fitting for over 7 years. Don't see a reason to go

to scuba.

DaBear

Richard Basiliere wrote:

 	  Quote: 	
		   FYI on the firefighter SCBA fittings. They are "all" standard GCA

Universal threaded fittings. Survivair, Scott, MSA, all the same. If

we have a big "event" multiple agencies will be "invited" and we need

to be able to fill our bottles from other Fire Dept compressors or

cascade systems. I'd love to have the SCBA adapter to Russian

airplane - the SCBA bottles are a dime a dozen.

- The Matronics Yak-List Email Forum -
 
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BasiliereR(at)ci.boulder.
Guest

Posted: Mon Jan 09, 2006 1:22 pm Post subject: Air bottles



If I'm correct (think I am - while looking at Sarah's Yak-55 and my SU-29)

#1.  There is an anti back flow valve just inside the fuselage from the external fill connector - other wise you would never be able to DC (disconnect) without losing all the air you just put in.

 

#2. Our Fire Dept compressors and cascade systems are set to be full (to be able to fill bottles at..) 4500-5000psi.  We NEVER see less than 2500 psi on our cascade.  Our compressor works just like yours - it pumps up to 4500 psi as the system drops below that.  It does our FF's no good to enter a burning building with a tank less than full - 4500 + 10%.  There would be a winnable liability suit...

 

#3.  This is the same system that fills the 80 cu ft SCUBA bottles our Dive Search and Recovery team uses

 

#4  I guess it goes without saying that at those pressures there is NO WAY there could ever be any back flow from a system that maxes out at 50 bar - 750 psi - whatever.

 

Again respectfully,

Lt. rick b 

 	  Quote: 	
		  >> fish(at)aviation-tech.com 1/9/2006 12:36:42 PM >>>

	


Yaksters,

I can not beleive that a fire dept, will allow there cylinder to connect to

your system. This is dangerous!

Once the pressure equilizes, the air can possably backflow into there tanks.

at this point there tanks are contaminated, and cannot be used for breathing

air until they are checked and cleaned. That is why you leave some pressure

in cylinders to keep them from becoming contaminated.

I would also have some concern about filling tanks at a shop as the same thing

can happen to their systems. Once the pressure equilizes form their tanks to

yours, there system will become contaminated.

I have heard to many stories about divers who had problems with thier air air

(compressors need to be maintained also), which sometimes leads to contaminated

air. That I would be rather error on the side of safety when it comes to breating

air (compressed or Oxygen).

Fly Safe

John fischer

 	  Quote: 	
		  

SCUBA to commie airplane adapters can be ordered from my  former partner >at

L39ZAparts(at)hotmail.com unless the Kazakistan warrants caught up with >him. 	


 	  Quote: 	
		  

I defer to your experience, which is probably more recent than mine.  In >the

mining industry, NIOSH allows only certified systems.  Our safety >engineers 	


determined that using a part (cylinder) from MSA on a >regulator from Scott

constituted an uncertified "system".  They were >fanatics about things like

that, not like FAA un-approved parts regs. 

 	  Quote: 	
		  

At another job, we changed from Scott to a German-built system, >Interspiro

perhaps.  My recollection is that those fittings were >incompatible with the 	


existing filling fittings, but I wouldn't swear to >it.  It was many years ago.

pa3arw(at)euronet.nl
Guest

Posted: Tue Jan 10, 2006 6:51 am Post subject: Air bottles



As I said, be carefull in doing this...the fire fighter and/or scuba dive

bottles maintain 300 or 200 bars of pressure. Our bottles will never

equalize with these ones...remember we only need 50 bars.....backflow will

never occur...before that either the yak bottle has been blown to pieces

(and your Yak as well....) or the pressure valve has released...I hope for

you the latter.....

Hans

-----Oorspronkelijk bericht-----

Van: owner-yak-list-server(at)matronics.com

[mailto:owner-yak-list-server(at)matronics.com] Namens fish(at)aviation-tech.com

Verzonden: maandag 9 januari 2006 13:37

Aan: yak-list(at)matronics.com

Onderwerp: Re: Air bottles

Yaksters,

I can not beleive that a fire dept, will allow there cylinder to connect to

your system. This is dangerous!

Once the pressure equilizes, the air can possably backflow into there tanks.

at this point there tanks are contaminated, and cannot be used for breathing

air until they are checked and cleaned. That is why you leave some pressure

in cylinders to keep them from becoming contaminated.

I would also have some concern about filling tanks at a shop as the same

thing

can happen to their systems. Once the pressure equilizes form their tanks to

yours, there system will become contaminated.

I have heard to many stories about divers who had problems with thier air

air

(compressors need to be maintained also), which sometimes leads to

contaminated

air. That I would be rather error on the side of safety when it comes to

breating

air (compressed or Oxygen).

Fly Safe

John fischer

 	  Quote: 	
		  

SCUBA to commie airplane adapters can be ordered from my former partner

at

L39ZAparts(at)hotmail.com unless the Kazakistan warrants caught up with >him. 	


 	  Quote: 	
		  

I defer to your experience, which is probably more recent than mine. In

the

mining industry, NIOSH allows only certified systems. Our safety >engineers 	


determined that using a part (cylinder) from MSA on a >regulator from Scott

constituted an uncertified "system". They were >fanatics about things like

that, not like FAA un-approved parts regs.

 	  Quote: 	
		  

At another job, we changed from Scott to a German-built system, >Interspiro

perhaps. My recollection is that those fittings were >incompatible with the 	


existing filling fittings, but I wouldn't swear to >it. It was many years

ago.

L39parts(at)hotmail.com
Guest

Posted: Tue Jan 10, 2006 6:54 am Post subject: Air bottles



Air flows from high pressure to low, and there are spring loaded check

valves throughout the filling systems that keep "equalized" pressure from

ever really being equal. Even without them, no system fills the "empty"

tank to a higher pressure than the supply (it's a physics thing) so it then

starts flowing the other way.

Your're right, you can't be too safe. That's why many people buy AVIATORS

breathing oxygen instead of that nasty old welding oxygen (cynicism alert-

if you're gullible stop reading now) which is full of water/oil/bugs/cat

entrails.

gus.fraser(at)gs.com
Guest

Posted: Tue Jan 10, 2006 7:12 am Post subject: Air bottles



Speaking of the check valve. The check valve on my fill port has a slow

leak, are the balls the same as the ones in the uplocks ? If so who was

offering the hard balls a while ago, and I am talking durons not anything

else.

Gus

cgalley(at)qcbc.org
Guest

Posted: Tue Jan 10, 2006 7:18 am Post subject: Air bottles



Ron, Your statement about welding oxygen might have been tongue in cheek but

the facts are Welding oxygen has to be the most pure of the three common

specs. Aviators breathing is next followed by I believe. medical. In

reality ALL oxygen at this time is fractionally distilled from liquid air.

We are talking temps over 100° BELOW zero. Not possible for any water to be

in any of the three, so that when used for medicinal purposes, it is

sometime bubbled thru a water bath for the patient. So you can fill your

supplemental oxygen from any of these three but cheapest is the same as the

most expensive. Welding oxygen works fine but if Medicare is paying, get it

from the medical house.

Cy Galley

EAA Safety Programs Editor

Always looking for ideas and articles for EAA Sport Pilot

brian

Joined: 02 Jan 2006
Posts: 643
Location: Sacramento, California, USA

Posted: Tue Jan 10, 2006 7:28 am Post subject: Air bottles



H.Oortman wrote:

_________________
Brian Lloyd
brian-yak at lloyd dot com
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery

BasiliereR(at)ci.boulder.
Guest

Posted: Tue Jan 10, 2006 7:31 am Post subject: Air bottles



Exactly, thank you.  Don't believe it? Call Air Liquide

 	  Quote: 	
		  >> cgalley(at)qcbc.org 1/10/2006 8:17:34 AM >>>

Ron, Your statement about welding oxygen might have been tongue in cheek but

the facts are Welding oxygen has to be  the most pure of the three common

specs. Aviators breathing is next followed by I believe. medical.  In

reality ALL oxygen at this time is fractionally distilled from liquid air.

We are talking temps over 100° BELOW zero.  Not possible for any water to be

in any of the three, so that when used for medicinal purposes, it is

sometime bubbled thru a water bath for the patient.  So you can fill your

supplemental oxygen from any of these three but cheapest is the same as the

most expensive. Welding oxygen works fine but if Medicare is paying, get it

from the medical house.

Cy Galley

EAA Safety Programs Editor

Always looking for ideas and articles for EAA Sport Pilot

- The Matronics Yak-List Email Forum -
 
Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

dsavarese(at)elmore.rr.co
Guest

Posted: Tue Jan 10, 2006 7:39 am Post subject: Air bottles



Gus,

If the check valves in your airplane look like the ones in the 52, there are

no balls inside of it like the ones used on the shuttle valves for the gear

actuators. They have three components; a spring; bronze piston that is

square with rounded corners that has a hard rubber seal on the top; a disk

that the piston rubber seal presses against to seal it off.

I had to buy one last week and unfortunately none of the usual suppliers had

any in stock except the new central parts stocking location for Aerostar in

IL, Emory I couldn't believe the price they charged for one - $225.00.

But I think I've got an excellent fix that I will be testing that will cost

significantly less than $225.

I only wish the CJ check valves would cross to the 52 because I would buy

them from Doug Sapp in a heartbeat. The problem is the fittings on the

Russian check valves are male and the Chinese ones are female. Adding a

male to male fitting would seem like the logical solution. But then you run

into a space problem. ie: The additional space required for the Chinese

check valve with a male to male conversion fitting on each end would make it

virtually impossible for the original metal lines to fit properly. In some

cases it would be impossible. In particular, the check valve closest to the

main oil tank on the + (cross) fitting where the pop-off valve is located.

Dennis

dsavarese(at)elmore.rr.co
Guest

Posted: Tue Jan 10, 2006 7:51 am Post subject: Air bottles



Brian,

Only one minor correction with regards to the 52. On the 52 the main air

valve does not have to be opened to refill the pneumatic system from the

external air fill port.

As for using N2, I'm not going to go there again because this has been

cussed and discussed on numerous occasions over the years. I have my

personal experiences and so do you and many other people with regards to

filling a completely empty MAIN air system with N2 and then trying to start

the engine.

Dennis

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