Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Air bottles
Goto page 1, 2, 3 Next

Matronics Email Lists Forum Index -> Yak-List

View previous topic :: View next topic

Author Message

gus.fraser(at)gs.com
Guest

Posted: Tue Jan 03, 2006 6:04 am Post subject: Air bottles



I used to carry the adapter around with me but recently I have changed. I

now carry a paintball gun tank. It is a 4500 pound tank with a regulator to

800psi on the output. Paintball is the fastest growing extreme sport in the

US and shops for this are popping up all over the place if I need a refill.

The tank is about a foot long and about 4 inches around so takes up little

space. I can send pictures if anyone is interested.

Gus

dave(at)davelaird.com
Guest

Posted: Tue Jan 03, 2006 8:14 am Post subject: Air bottles



I also have a paintball tank...

I get it filled from either a paintball store, or a scuba place...

the scuba guys use really good 4 stage compressors with filters and

there is very little moisture in the air at that pressure, and oh,

best of all, the scuba place I go to doesn't even charge for

a paintball bottle refill!!!

Mine is a 72ci bottle with 800psi on the output, too... mine is only

rated for 3000psi... but was cheap. about 80 bucks.

I also have a screw on regulator for it that lets me regulate down to

350psi for the nose strut. I use it straight out at 800psi

for the main struts.

I have not used it to fill the CJ's main air tank (yet) but have

wondered if the CJ tank is all the way down, and I have a 72ci tank

of 3000psi air, how "full" would the CJ tank be after "emptying" the

72ci paintball tank into the CJ?

anyone know?

Gus?

( I just haven't run out of air in Betty, and besides, Brian put that

scuba tank in her too!)

Dave Laird

N63536 1983 CJ6A "Betty"

Dallas

On Jan 3, 2006, at 8:03 AM, Fraser, Gus wrote:

I used to carry the adapter around with me but recently I have

changed. I

now carry a paintball gun tank. It is a 4500 pound tank with a

regulator to

800psi on the output. Paintball is the fastest growing extreme

sport in the

US and shops for this are popping up all over the place if I need a

refill.

The tank is about a foot long and about 4 inches around so takes up

little

space. I can send pictures if anyone is interested.

Gus

gus.fraser(at)gs.com
Guest

Posted: Tue Jan 03, 2006 9:20 am Post subject: Air bottles



David,

Remember that your 3000PSI will 'expand' to 750 psi in the main tank. Treat

the paintball tank like a capacitor it has a load of charge so your small

tank should give you a full charge of the 6 ltr bottle in the plane.

Gus

dave(at)davelaird.com
Guest

Posted: Tue Jan 03, 2006 9:54 am Post subject: Air bottles

`On Jan 3, 2006, at 11:20 AM, Fraser, Gus wrote: David, Remember that your 3000PSI will 'expand' to 750 psi in the main tank. Treat the paintball tank like a capacitor it has a load of charge so your small tank should give you a full charge of the 6 ltr bottle in the plane. Gus`

cool! thanks Gus.... I think I'm going to empty the main air this
week and then go ahead and fill it from the paintball tank to try it
out!
Dave

rvfltd(at)televar.com
Guest

Posted: Tue Jan 03, 2006 11:11 am Post subject: Air bottles



Dave,

Remember that 750PSI is 51 atms. While this is just 1 ATM over the

operating pressure I would recommend that you use a bit of caution if your

bottle has not been off and tested recently. If it has been tested

recently, I doubt that you have anything to worry about. The CJ6 tech

manual says that operating pressure is 50 atms (page 104) and that the 8

liter tank should fill in 22 minutes (page 107).

As a group we have been extremely lucky in that we have not had any main air

bottles explode yet (that I know of). I would caution you all to not become

complacent and feel that because we have not had a failure that this is

really not a potentially serious problem. A in-flight failure could have

very serious consequences. If your bottle has not been checked, get it

done, record it in the log book, it's very cheap insurance.

Always Yakin,

Doug Sapp

viperdoc(at)mindspring.co
Guest

Posted: Tue Jan 03, 2006 11:17 am Post subject: Air bottles



Gus,

Send me pictures of your tank. I am using a pony tank for backup.

viperdoc(at)mindspring.com

Doc

JBernier(at)dart.org
Guest

Posted: Tue Jan 03, 2006 11:43 am Post subject: Air bottles



Dave,

When solving for this pressure drop I get 385 psi final pressure. That is using Doug's 8 liter bottle and Boyles Law. I trust that he is correct. I assumed that the main tank was empty. That turns out to be 27 atm. I have started my plane on the amount. The plus side is that you will have over 9 liters of air at that pressure instead of 8, if you leave the bottle connected. When you empty the tank, then fill it from the paint gun bottle, try to start it cold. That will be the final test. But here in Dallas it isn't really cold, ever.

You never know for certain until you try.

Jim B

 	  Quote: 	
		  >> rvfltd(at)televar.com 01/03/06 1:10 PM >>>

Dave,

Remember that 750PSI is 51 atms. While this is just 1 ATM over the

operating pressure I would recommend that you use a bit of caution if your

bottle has not been off and tested recently. If it has been tested

recently, I doubt that you have anything to worry about. The CJ6 tech

manual says that operating pressure is 50 atms (page 104) and that the 8

liter tank should fill in 22 minutes (page 107).

As a group we have been extremely lucky in that we have not had any main air

bottles explode yet (that I know of). I would caution you all to not become

complacent and feel that because we have not had a failure that this is

really not a potentially serious problem. A in-flight failure could have

very serious consequences. If your bottle has not been checked, get it

done, record it in the log book, it's very cheap insurance.

Always Yakin,

Doug Sapp

- 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

dave(at)davelaird.com
Guest

Posted: Tue Jan 03, 2006 11:55 am Post subject: Air bottles

Thanks Jim, I'll post the results when I (carefully) do the test. Dave On Jan 3, 2006, at 1:42 PM, Jim Bernier wrote: Dave, When solving for this pressure drop I get 385 psi final pressure. That is using Doug's 8 liter bottle and Boyles Law. I trust that he is correct. I assumed that the main tank was empty. That turns out to be 27 atm. I have started my plane on the amount. The plus side is that you will have over 9 liters of air at that pressure instead of 8, if you leave the bottle connected. When you empty the tank, then fill it from the paint gun bottle, try to start it cold. That will be the final test. But here in Dallas it isn't really cold, ever. You never know for certain until you try. Jim B

pa3arw(at)euronet.nl
Guest

Posted: Tue Jan 03, 2006 12:14 pm Post subject: Air bottles



Guys,

The only thing we carry around during a trip in our Yak52 is a hose, which I

had made especially for this purpose, with on one side an adapter which goes

on the plane and on the other side an adapter with release valve which goes

on a scuba dive bottle. In Europe this is a standardized connector, i.e.,

these scuba dive bottles have the same connector as all air bottles used by

the fire brigades at airfields/airports and what have you.

There is always a nice fire fighter at an airport or airfield who wants to

give you a hand to charge your air bottle in the plane with one of his.

Be aware though: these bottles have 200 bars (and nowadays even 300 bars),

so open them very slowly. We are using this method since years already and

it works perfectly.

Hans

Yak52 pilot from Holland

rvfltd(at)televar.com
Guest

Posted: Tue Jan 03, 2006 12:16 pm Post subject: Air bottles



Jim,

Many thanks for the heads up/correction, I did not check the numbers and am

guilty of assuming that they were correct. You owe me a beer Gus!

What exactly is Boyles law?

Always Yakin,

Doug Sapp

JBernier(at)dart.org
Guest

Posted: Tue Jan 03, 2006 1:15 pm Post subject: Air bottles



Doug,

Boyle's Law simply says that the initial pressure over the final pressure is equal to the final volume over the initial volume. Or, with constant temperature, the volume of a given mass of gas is inversely proportional to the pressure which is exerted upon it. I cheated and looked it up.

So, is it 8 liters or 6? Makes a big difference in pressure. If it 6 liters then the resulting pressure would be 493 psi, 33.5 atm.

Jim

 	  Quote: 	
		  >> rvfltd(at)televar.com 01/03/06 2:16 PM >>>

Jim,

Many thanks for the heads up/correction, I did not check the numbers and am

guilty of assuming that they were correct. You owe me a beer Gus!

What exactly is Boyles law?

Always Yakin,

Doug Sapp

- 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

viperdoc(at)mindspring.co
Guest

Posted: Tue Jan 03, 2006 1:19 pm Post subject: Air bottles



 	  Quote: 	
		   [Original Message]> What exactly is Boyles law?

Always Yakin,

Doug Sapp

	


Doug,

Boyles law states that " when the temperature rmeans constant, the volume

of agiven mass of gas baries inversely as it pressure" Expressed as

follows:

V1/V2 = P1/P2

Where V1 is the initial volume: V2 is the final volume: P1 is the initial

pressure: and P2 is the final pressure.

For Physiological purposes, Boyle's Law can be considerd a precise

statement of facts. Under high-pressure situations, however, Boyle's Law is

only an approximate statement because of the attraction of the gas

molecules for each other increases the effect of applied pressure and the

space occupied by the molecules themselves, which in effect decreases the

effective volume.

Doc

viperdoc(at)mindspring.co
Guest

Posted: Tue Jan 03, 2006 2:17 pm Post subject: Air bottles



[Original Message]> What exactly is Boyles law?

 	  Quote: 	
		   Boyles law states that " when the temperature remains constant, the

volume 	


 	  Quote: 	
		   of a given mass of a gas varies inversely with it's pressure" Expressed

as 	


 	  Quote: 	
		   follows:

V1/V2 = P1/P2

Where V1 is the initial volume: V2 is the final volume: P1 is the initial

pressure: and P2 is the final pressure.

For Physiological purposes, Boyle's Law can be considerd a precise

statement of facts. Under high-pressure situations, however, Boyle's Law

is 	


 	  Quote: 	
		   only an approximate statement of the facts because the attraction of the

molecules for each other increases the effect of applied pressure and the

space occupied by the molecules themselves, which decreases the

effective volume.

Doc

- 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

rvfltd(at)televar.com
Guest

Posted: Tue Jan 03, 2006 3:22 pm Post subject: Air bottles



Roger,

Thanks much, great post, very helpful :0)

Always Yakin,

Doug Sapp

viperdoc(at)mindspring.co
Guest

Posted: Tue Jan 03, 2006 6:47 pm Post subject: Air bottles



Doug,

I hope you read the corrected version. This one looks like gobbly-gook! My

nurse came an grabbed me as I was trying ti rapidly type the answer out.

Anyway, hit send inadvertently as I going to help her. 

Doc

 	  Quote: 	
		   [Original Message]

From: doug sapp <rvfltd(at)televar.com>

To: <yak-list(at)matronics.com>

Date: 1/3/2006 5:22:44 PM

Subject: RE: Yak-List: Air bottles

Roger,

Thanks much, great post, very helpful :0)

Always Yakin,

Doug Sapp

- 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

cd001633(at)mindspring.co
Guest

Posted: Tue Jan 03, 2006 7:37 pm Post subject: Air bottles



Doug,

This is a very good and important point!

This topic was discussed before right after the Emergency Air Tank exploded

in the Yak-50 in England... He was really lucky as this occurred as he was

taxiing out for take off... You used mild words for the potential

consequence for in-flight failure. I suspect that when this 'baby' goes off

in flight it could very well separate the structure behind the rear seat

outright or sever enough longerons etc. that the aerodynamic load would

finish the job. Some of the engineers on this here list could calculate the

energy release upon such failure for either the main or emergency tanks (CJ

main air tank is larger than the Yak-50, 52). Either way, even if the

structure holds to landing, I suspect that the pilot would need to launder

his flight suits a couple of times while the GIB will need to be carried out

of the aircraft.

I think there is a shop in California who does pressure tests for our air

tanks, does anyone have their contact info handy?

Thanks,

Sam Sax

wlannon(at)cablerocket.co
Guest

Posted: Tue Jan 03, 2006 7:53 pm Post subject: Air bottles



Dave;

The CJ air tanks are 12 liters (main) and 3 liters (emerg). With the main

air valve open both tanks are charged from the external supply (or from the

compressor)

With the main air valve closed only the small emergency tank will be

charged.

Arithmetic gives me a headache but here are some numbers for you that

suggest you treat that 3000 psi bottle with great respect.

1. Don't know the actual size of your paintball tank but lets call it 6" dia

X 24" long. That represents an internal volume of 0.3927 cu. ft.

Into that is packed 72 cu ft of air or 183 tank volumes.

2. One paintball tank volume (0.3927 cu ft) = 11.12 liters

3. Without getting too involved in the arithmetic that means when you

transfer that 3000 psi to the CJ main you would theoretically have slightly

less than 3000 psi in that tank. If your paintball tank volume is less than

my estimate then you will have more than 3000 psi. Theoretically of course

since the CJ tank (and/or most of the aircraft) would have exploded long

before then.

Please be very cautious. You are dealing with a bomb

Walt

wlannon(at)cablerocket.co
Guest

Posted: Tue Jan 03, 2006 8:31 pm Post subject: Air bottles



Ignoring the emergency tank and assuming the paintball tank as estimated

Boyle's Law say's there will be 2800 psi in the CJ main tank.

Walt

Dave;

The CJ air tanks are 12 liters (main) and 3 liters (emerg). With the main

air valve open both tanks are charged from the external supply (or from

the compressor)

With the main air valve closed only the small emergency tank will be

charged.

Arithmetic gives me a headache but here are some numbers for you that

suggest you treat that 3000 psi bottle with great respect.

1. Don't know the actual size of your paintball tank but lets call it 6"

dia X 24" long. That represents an internal volume of 0.3927 cu. ft.

Into that is packed 72 cu ft of air or 183 tank volumes.

2. One paintball tank volume (0.3927 cu ft) = 11.12 liters

3. Without getting too involved in the arithmetic that means when you

transfer that 3000 psi to the CJ main you would theoretically have

slightly less than 3000 psi in that tank. If your paintball tank volume is

less than my estimate then you will have more than 3000 psi. Theoretically

of course since the CJ tank (and/or most of the aircraft) would have

exploded long before then.

Please be very cautious. You are dealing with a bomb

Walt

yak52driver(at)earthlink.
Guest

Posted: Tue Jan 03, 2006 9:11 pm Post subject: Air bottles



Yakkers;

You should pressure test your air bottles on occasion...................

For pressure testing tanks contact:

TYM's INC.

414 West Arbor Vitae St.

Inglewood, CA 90301

Phone 213-678-3330 or 310-673-3330

They have all the fittings needed to do our tanks. They have done

many YAK and MIG tanks for other customers. They're located near LAX.

Frank

wlannon(at)cablerocket.co
Guest

Posted: Tue Jan 03, 2006 11:44 pm Post subject: Air bottles

Display posts from previous:

	Matronics Email Lists Forum Index -> Yak-List	All times are GMT - 8 Hours Goto page 1, 2, 3 Next
Page 1 of 3

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum