what is best deal on new airtank . and where to buy accys ???

Lou...a "fast fill" generates heat, heat generates condensation of any moisture in the air used to fill. Granted there should be no moisture in the air you fill your tank with, but with that thinking I should have blue eyes, thick black hair, and exceptional good looks....life ain"t like that!

As fast fill hot air cools, pressure goes down, requiring the need to wait and then add air.

In the end, a "slow fill" is the best way to exchange air from a fill tank to a smaller pcp cylinder.

To my knowledge, the hydro people will tell you if the tank cannot be re-hydro'd. Steel and aluminum tanks are hydro'd many years over their anticipated life expectancy. Carbon fiber DOT certified tanks can be hydro'd more than once...if there's a problem, expect them to advise you it is at it's life's end.

Further, frequency of use isn't necessarily a factor in life expectancy, unless the tank was repeatedly "cave filled", or filled past it's rated maximum pressure. The standard used to be 3/5ths maximum hydro pressure was how a tank was rated for psi fill maximum. Commercial scuba tanks are used thousands of times in a season at a busy resort. Use doens't necessarily mean "wear" in a scuba tank...unless it is abused by no maintenance procedures over it's lifetime.

Things may have changed and use the above info at your own risk!!!



That's what I know...use it how you will. Not everyone will agree, individual mileage always varies!!!

Hoot

Well hope your not getting wet air in your bottles condensate water is not like tap water it is pure and absorbs carbonic acid from the air which is corrosive for aluminum which is the bladder in a carbon fiber tank if by chance you are not taking the necessary measures to insure you fill the tank with dry air then as the temperature drops corrosive water droplets will form in your bottle and cause pitting in the aluminum bladder until eventually it fails a hydro test preferably or a fast fill unfortunately. 

If I'm you I buy a new bottle your well being and possibly your life is at the mercy of the integrity of your fill station not the best component to save a buck on IMHO I mean your worried about a cheap China hose bursting and whipping your ass what about an old used tank bursting and taking your life be safe brother and have fun 

Lou...a "fast fill" generates heat, heat generates condensation of any moisture in the air used to fill. Granted there should be no moisture in the air you fill your tank with, but with that thinking I should have blue eyes, thick black hair, and exceptional good looks....life ain"t like that!

As fast fill hot air cools, pressure goes down, requiring the need to wait and then add air.

In the end, a "slow fill" is the best way to exchange air from a fill tank to a smaller pcp cylinder.

To my knowledge, the hydro people will tell you if the tank cannot be re-hydro'd. Steel and aluminum tanks are hydro'd many years over their anticipated life expectancy. Carbon fiber DOT certified tanks can be hydro'd more than once...if there's a problem, expect them to advise you it is at it's life's end.

Further, frequency of use isn't necessarily a factor in life expectancy, unless the tank was repeatedly "cave filled", or filled past it's rated maximum pressure. The standard used to be 3/5ths maximum hydro pressure was how a tank was rated for psi fill maximum. Commercial scuba tanks are used thousands of times in a season at a busy resort. Use doens't necessarily mean "wear" in a scuba tank...unless it is abused by no maintenance procedures over it's lifetime.

Things may have changed and use the above info at your own risk!!!



That's what I know...use it how you will. Not everyone will agree, individual mileage always varies!!!

Hoot

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I mostly agree with everything in your post but the moisture part. If a tank is filled with confirmed 'dry' filtered air from a compressor, scuba fill shop, or from a large nitrogen tank, then thats it, no water will be introduce to any tanks filled with the large dry' fill tank regardless of speed of fill from that 'dry tank. If the fill tank is not dry, has water vapor in it from a poorly set up compressor, than speed of fill won't change anything, you will get that water in what ever tank you fill with that wet tank





The valve on many tanks humans use to breath with(SCUBA or SCBA) have a short pipe on the tank valve that sticks down into tank so if any water/debris is in the tank, no matter the position of the tank, the water can't get to the end of the pipe as water/debris settles to the lowest point. Water/debris is only able to find the exit pipe if the tank valve is opened fully for many seconds creating so much turbulent flow it carries out water/debris. Something that never happens with a regulated human breathing air tank. But slowly cracking open/regulating the valve of an unregulated tank for a fast fill will not create enough turbulence to let anything on the tank bottom come out that pipe.

Since we don't use these tanks to breath with and tank is used from standing up or laying on its side, I remove this pipe making the valve port flush with the bottom of an inverted/upside down tank. That way I can invert the tank and slightly crack the valve to make sure no water/mist comes out confirming I've got a dry fill. Crack the valve open slowly and just slightly for this check, any water will come right out.

As Always when filling with a compressor keep it dry/clean by using appropriate filters/desiccants/etc... Or best yet, I love my nitro tank for pcp, imo dry/clean inert nitrogen is by far the best way to fill pcp/pcp tanks hands down. If like most, not using a regulator on the big nitro tank, just have to not fall asleep at the wheel letting your pcp gun/tank get filled to 6000psi. Thats the reason some manufactures recommended against nitrogen, its a liability for asleep at the wheel fill to 6000psi types...

Always have tanks hydro tested as required, never use outdated tanks. Always keep an eye on fill station hoses and connections, etc,, for wear, abrasion, kinks, leaks etc. Many hydro shops will check these for you also if you're not confident of doing it.

jmo

Hepotter makes some very good points and is spot on in his advice.

Concerning your Airhog tank, I had one a few years ago. IIRC, it was CF wrapped (not permitted for diving), 100cu/ft, rated for 4500 psi, and utilized a standard, scuba K-Valve. The K-Valve is US standard for scuba, while DIN (German Institute of Standards) is the metric version used by much of the world. My Airhog tank required a hydro every three years instead of the normal five. Plus the dive shop required (all of them do) a current, annual visual inspection sticker before they would fill it. This tank had two, important maintenance requirements noted on the bottle. The first, stamped into the shoulder of the bottle gives you the WP and hydro date which is good through the end of the indicated month and year. The second was a label visible under the CF wrap indicating the hydro interval and tank life. In addition, each dive shop adheres its own label showing visual inspection status ( an inspection of the interior of the tank using a light stick). These are not suggestions. They are requirements for safety. HPA can be very unforgiving if not properly contained. As a DM in the Bahamas for many years, I have filled, visually inspected the interior, whipped, tumbled and performed standard maintenance on most everything used for diving. However, CF tanks are not rated for diving and my only association with them is through airgunning.

HPA tanks expand when filled and contract when depleted. These cycles cause stress to the tank and determine its life cycle. A Hydro test measures the expansion ( by water displacement) and, as Hoot says, pumps the tank past its working pressure. A properly maintained scuba tank (especially those made of steel) can last many decades. A CF tank is essentially disposable after "X" years and should not be reused. There are a few exceptions, but these are the general rules that are governed by safety requirments. If you check these indicators and find any tank out of spec it must be ditched. If not for your own safety, do it for the safety of your surviving children, friends, neighbors and pets. Your insurance company will not pay and claim where such warnings were ignored. And the attorneys suing you or your estate will become even more fat and happy.

If you need a new, large tank, take a good look at steel. They can last your lifetime if you service it according to schedule. I have used steel tanks from the '60s that have been filled and emptied 3X/day, 24/7/365 since new. I also use a steel, 105 cu/ft, 3500psi (3700 with a + hydro test) as my main AG tank. Steel tanks used to be expensive, but the price of HP CF tanks has risen to the point that they are now often less. That would be my recommendation if you are not using some of the extreme rifles that require a higher pressure.

Anyway, have fun and be safe!

If your Airhog tank has the date 11-15 on it that should be the date of birth which makes it only 4 years old. If that's the date of the last hydro, there will be another date for the D.O.B. If that is the case, it will be due for a hydro in 12 months and should be good for another 10 years providing it passes the inspections. The 88 and 98 cubic foot tanks are the same. The vendors estimate the volume using different pressures to exaggerate the capacity for marketing reasons. Don't believe that mumbo jumbo about fast or slow fill valves causing heat and moisture. Go with what floats your boat. If your tank has corrosion from bad air, it will be picked up at the inspection and will be destroyed. Basic valves without gauges can be had for as little as $20 USD on AliExpress. I have one on order at the moment. Just make sure the valve thread matches the tank. 

I just bought one from here it arrived yesterday. Good quality and delivered by UPS. Only good if you fill yourself. Bigger ones are available from the same vendor. https://www.aliexpress.com/item/33053567366.html?spm=a2g0s.9042311.0.0.1e0b4c4diZcr8W You can get it with your choice of valves but I found it cheaper to get the valve from another supplier.

I just bought one from here it arrived yesterday. Good quality and delivered by UPS. Only good if you fill yourself. Bigger ones are available from the same vendor. https://www.aliexpress.com/item/33053567366.html?spm=a2g0s.9042311.0.0.1e0b4c4diZcr8W You can get it with your choice of valves but I found it cheaper to get the valve from another supplier.

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Yeah that's the same place I got my tank no DOT label though so you have to fill it yourself and don't get caught with it in back of your truck.