So I've noticed when you fill a bottle to its max fill pressure of 4500psi, later after it cools down the pressure drops to like 4300ish psi. I know, laws of physics at work here not getting around that. My bottle is a 90cc pony from joe B. so I don't get many fills out in the field before needing a refill. Every bit of air counts to me, so I've been thinking how to use this to my advantage. What I do is put my bottle in the freezer after I fill to 4500 psi with the yong heng, let it sit in there for a hour or two. Then I pull out the bottle that now reads 4200-4300 psi, connect back up to my yong heng and top off back up to 4500psi while still ice cold. When the bottle warms back up to room temp. it will read 4800psi and give a extra fill for the wildcat.
"Chilled fill"
- Thread starter Kayakairgun
- Start date
I do this before I hit the dive shop and I can get a 5000psi fill once she warms up here in South Florida. Makes my 300bar fills last a little longer.
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Not sure I would Thermal Cycle an Aluminum and Fiberglass wrapped bottle like that. Differential Expansion rates may lead to delamination of the Glass/Aluminum interface.
Just a thought, I'm not a Metallurgist, but in effect you are performing a Thermal Shock Test (you can read about them in MIL-STD-610).
Smitty
Just a thought, I'm not a Metallurgist, but in effect you are performing a Thermal Shock Test (you can read about them in MIL-STD-610).
Smitty
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That extra air could cost you. Need more air? You know what the right thing to do is. GET A BIGGER TANK I’ve got one if those little tanks and it’s nice enough but most of the time I’m not carrying the thing so it’s just as easy really to take the big tank with me.
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You will get a little excitement about the time a burst disk goes. A couple 100 pounds OK but 10%??? Had one go in the dive shop the other day and it gets kinda windy.
Blew half the inventory off the walls and had 4 men running like kids.
Blew half the inventory off the walls and had 4 men running like kids.
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I know what you mean, there's a dive shop that fill scuba tanks for the commercial dive boats just 2 bays down from my shop and he had a disk let go and I thought I was back in the air force with a F-15 taking off. Crazy scary.
Aloha, Keone
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Thanks for the feedback guys!
I know I should get a bigger tank for more fills. I used do some of my shooting form my kayak, so I had to keep my air gun footprint as small as I can.
As for as the Thermal Cycle thing goes Im no Metallurgist myself. As a young man I completed the fire academy here in Houston and volunteered at the fire house for about a year. In the academy, on burn days with the same scott scba bottles we ran into rooms with plus 300 degree air temps, crashing into concrete walls, stairs and the like. Had man down drills where we drug men down multiple stories, over tools and hot surfaces by many yards all with the bottle between them and the ground. These airpack bottles are very strong, as they where made for emergence service. We as air gunners give these scba bottles a very gentle life.
I know I should get a bigger tank for more fills. I used do some of my shooting form my kayak, so I had to keep my air gun footprint as small as I can.
As for as the Thermal Cycle thing goes Im no Metallurgist myself. As a young man I completed the fire academy here in Houston and volunteered at the fire house for about a year. In the academy, on burn days with the same scott scba bottles we ran into rooms with plus 300 degree air temps, crashing into concrete walls, stairs and the like. Had man down drills where we drug men down multiple stories, over tools and hot surfaces by many yards all with the bottle between them and the ground. These airpack bottles are very strong, as they where made for emergence service. We as air gunners give these scba bottles a very gentle life.
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And because of stories like yours is why bottles used in those settings get swapped out pretty quickly.
Also do we really treat them nicer....I am not so sure of that, I am under the impression that pressure cycles are something that really stresses the tanks as well as temp extremes. In the fire house the bottle could sit a week with no use, in the air gun world that same week could see it refilled a great many times.....does going from 2800 psi up to 4000 put more stress on the tank.....I would think it does.
Personally I am in the camp that freezing your tank is not a good idea.
I really think we are one big kaboom and then the full weight of the guberment will be on us. It will not be long before people start to see our fancy red ryders as "real" guns....guns that shoot at 100 yards plus with power to take down deer, hogs and in time I think it will be people as well. I think we will see regulations on air before we see tighter regulations on say black powder.
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I agree completely with Cherokee140's last paragraph ! In order to protect our sport and keep the many levels of government out of it we all need to be very responsible. Texas just approved air guns for deer hunting and several of the local hunters and the two game wardens posted in my small town are really interested in checking out my little air gun collection. That is great for the sport. On the other hand I am also a commercial UAV pilot and I can tell you what Washington has recently done to the RC/Drone sport and commercial flying is very oppressive !! Wait till they really discover what LDC's are !! Keep it safe out there !!
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