Compressor question

[Andy321]

Hi all

So in a moment of craziness I yesterday took a visit to high pressure airsofts store in Scunthorpe (fantastic set of lads btw) and after dropping a wod, I am now the proud owner of a Gen 2 Wolverine MTW billet SBR.

I'm not a novice to airsoft but this is my first venture in to the world of HPA. The MTW build quality is brilliant also its so quiet and the trigger response is something else ? 

I picked up all the kit needed including 2X 48ci 3000psi tanks. I'm now looking at means of filling the tanks, I don't want to solely rely on my field for refills in case of problems their end and being unable to play with the MTW. I would like to be able to top them up at home before game days and for plinking/testing.

So I was looking at a 5 or 7 litre scuba tank for refills but the guys at high pressure airsoft filled my two new tanks with there compressor. I was shocked when it only took only about 5 mins per tank for a full fill. I was even more shocked when I saw it was one of the 300 bar compressors which can be had off Amazon for roughly £200ish (not much more than a scuba tank setup). The chaps in the store said it's been absolutely great for them and gets hammered daily refilling tanks.

So question is, have any of you got one of these and what's your thoughts? Are they a viable option to a scuba tank, I'm leaning towards one myself as it seems like the best option for me personally. I understand the importance of making sure the airfilter is clean and absolutely no oil getting in the fill valve.

A sneaky pic of the latest addition attached...

Thanks

View attachment 84128

 

[Alimcd]

Google oil flash fill explosion and then trust someone else to maintain a compressor.

There have been some pretty gnarly explosions from oil getting into the bottle regulators.

I’m just about to buy a dive tank as I’m in the same position as yourself

 

[Tommikka]

Fills should come from:

A maintained professional compressor, costing thousands, and run steadily

A pre filled scuba cylinder - filled from a maintained professional compressor 

A stirrup pump at home 

If you live in deepest Canada, playing the odd game in your remote woods then perhaps consider a dual system of a workshop compressor and a discontinued Tom Kaye shoebox booster compressor. Run it on a stop start basis over a day or longer

A compressor costing a few hundred should not be ‘thrashed’ daily

How warm were your cylinders when they were filled?  What pressure were they filled to, and how much did they drop when cooled back down?

A professional compressor is best used in a cascade manner into a substantial holding cylinder, players cylinders drawing from the master and the compressor kicking in to top up the master 

See here for the UKPSF basic air safety HPA1 sheet

https://m.facebook.com/nt/screen/?params={"note_id"%3A796094531191401}&path=%2Fnotes%2Fnote%2F&_rdr

 

[sjhirst]

Ive just bought the GX CS2 Compressor. So far its been brilliant.

Its not super fast, but seems a very capable portable compressor.

 

[Andy321]

Hi thanks for the replies.

The more I'm hearing and reading I'm starting to regret going the hpa route as I'm now paranoid my tanks are going to randomly explode and decapitate anything in there path ?

Please someone convince me this hpa game is safe as long as your not a complete knobber and have respect.

As for the compressor in there shop, it was the type you can get on Amazon, same as the one made by Yong Heng but it was unbranded. They filled my tanks from empty to 3000psi in about 5 mins, tanks were slightly warm to the touch after filling (not very warm). It auto shut off at 3000 psi (although I would never leave a compressor unattended whilst filling) and the tanks were showing 3k on the gauges and maintained that same 3k once cooled. If I did get one I was also looking at picking up a molecular sieve filter to run with it.

I have been looking at stirrup pumps as well. Roughly how many pumps does it take to fill a 48ci tank from let's say 1k to 3k psi?

Other option is a scuba tank. To increase on the number of refills between getting it filled up, could I pickup a 300 bar tank (5 or 7 litre), have it filled to roughly 250/260 bar and use that for more fills on my 48ci tanks? Again being careful and slow on the valve as the scuba tank would have the potential to overfill the smaller tanks. I've read mixed opinions on this but I see alot of people doing it this way without issue along as you are slow and steady and have respect.

Thanks again.

 

[Tommikka]

Please someone convince me this hpa game is safe as long as your not a complete knobber and have respect.

.

HPA is perfectly safe as long as you are not a complete nobber and treat it with respect 

You need to do absolutely no maintenance to your cylinders 

If they are excessively filled the high pressure burst disk will fail, make a scary bang noise, and safely exhaust the air

Just don’t have skin next to the burst disk, and if the cylinder is sat in a table then it will probably spin & bounce around - you don’t want the first thing it hits to be a fragile bone such as your skull 

Avoid this with steady fills and watch the gauge 

Ultimately a burst disk might fail due to the number of fills it has had cycling from low/no pressure to full pressure.  The majority will last the entire lifetime of a cylinder. 

If the regulator fails and too much pressure is released then the low pressure burst disk will will fail, make a scary bang noise, and safely exhaust the air

As above but a lower pressure and it lasts longer.

Minimise this by fitting a full nipple cover to avoid dirt on the nipple.  If you have no nipple cover then dirt will get onto the nipple, a sensible person will rub that off, but there will still be residue which gets blown into the cylinder on the next fill, then gets into the regulator. If it builds up over time then ‘performance’ is effected and a failure may occur - it becomes inefficient and doesn’t refresh quickly or it allows higher pressure through and the burst disk saves you 

Burst disks are your air fuses.

The high pressure burst disk is your mains trip/fuse cabinet, the low pressure burst disk is your plug fuse

Don’t ‘self service’ your cylinder and don’t lubricate it

You cannot overfill a cylinder and make it explode (unless you try very hard and replace the burst disks with solid bolts)

A flash fill failure is a very rare incident, I’m not aware of any for probably 15+ years (at least in the UK, Europe & US)

There were two back in the day, one at a site in Southampton and one at a European event.

At least one involved a specific type of cylinder which had a very thin lightweight design, and only had a maximum 5 year life.  This was not the cause of failure, but faith was lost and it’s manufacture was ceased

Other very lightweight designs have since been manufactured 

They all must be manufactured and tested to the same standards

The combination of caused of these failures were:

1) oil contamination 

In the UK case it was established that the user had not contaminated their cylinder with oil 

It was found that the oil contamination was due to someone else’s cylinder filled some point earlier 

2) high speed fills

The filling was of 4500psi cylinders, but at unregulated speeds 

Any filling generates heat, but the combination of oil, very high pressure, very fast filling generated a lot of heat very quickly and turned the cylinder into a Diesel engine - flash fill failure / flash fill explosion 

To avoid these:

Don’t use oil on the high pressure end

Even better don’t use any lube on your cylinder - if the cylinders regulator ever needs work then refer to a professional

(But at the price of 3000psi aluminium cylinders just buy a new one)

Don’t use unregulated fill systems 

Use the right fill pressure system - 3000psi / 206bar

(I’ll tell you something about scuba later)

Fill slowly, ideally top up often

If filling a lot (eg from low or empty) then start to fill for a short while holding the cylinder, stop, wait a moment, if it has got noticeably warmer then stop for longer and fill in shorter bursts 

Don’t use a full system without first familiarising with it - get shown how to fill by a competent person

The tournament paintball community learned these lessons when the flash fill incidents occurred.

The UKs scenario paintball community adopted them among event standards a few years later, including UKPSF air safety briefs before players would be permitted to self fill (an air pass would be handed out valid for a year)

I discovered that the tournament community forgot those lessons, and was relearning them again (luckily the sites / events  maintained regulated fills)

Stirrup pumps take a lot of pumps to fill.

I’ve got one, but I’ve never done enough for a fill.  I’m a team captain and I have peasants to do the hard stuff 

(However the stirrup isn’t intended for filling, only for a level of top up if ever required when away from a proper fill source)

Normally my advice is to fill a little bit and often - don’t let the cylinder drop far down, then top up to 3000psi

With a stirrup this is still valid advice - BUT the first strokes of the pump don’t put anything into your cylinder, they only bring the hose up to pressure until it matches the cylinders current pressure and opens the fill nipple valve.

Then subsequent pumps go to wider area of the cylinder and hose and begin to fill.

The more you drain the cylinder first, the quicker you actually pump air into it - but then need more strokes to get to your desired pressure 

If you’re doing a quick top up between games then there is the danger that in a short time all you manage to do is pressurise the hose, then run out of time before you get any air transferred

If you start from practically empty then you quickly get some pressure in, but have to get in enough to play

With a stirrup use slow, steady, firm pumps - all the way from top to bottom

Scuba cylinders are a good option - but if you have 3000psi in your scuba and fill your playing cylinders you won’t get 3000psi - you’ll get a fraction less as they equalise

Then on your next fill the scuba is starting below 3000psi, so you get even less and gradually the maximum you can get drops 

So avoid filling your filling cylinders to 3000psi, go for something like 2800psi and then don’t let it drop too far - fill straight away (You are then taking as little as possible from the scuba each time - and of course do it slowly)

If you get a 4500psi/300bar scuba it costs more, but you have much more spare capacity before it drops

But this brings the ‘danger’ of a 4500psi scuba source filling a 3000psi playing cylinder 

You could buy a regulated fill rig set to output 3000psi - at extra expense 

Or you control the flow, monitor all gauges and only fill the playing cylinder to 3000psi (or less)

High pressure air is very safe when treated with respect

 

[Andy321]

Wow thanks for the detailed response, some great info there, much appreciated. 

Think I might go down the scuba tank route for refills. Contacted a dive shop near me earlier today, he said they have some 12 litre 232 bar tanks available for £100. Only issue being that there used, he did say they have been recently hydro tested. Should I be concerned buying a used tank? Also roughly how many top up fills would I get from a 12 litre 232 bar tank, filling 48ci tanks to roughly 2500-2800 psi?

Thanks

 

[Tommikka]

Wow thanks for the detailed response, some great info there, much appreciated. 

Think I might go down the scuba tank route for refills. Contacted a dive shop near me earlier today, he said they have some 12 litre 232 bar tanks available for £100. Only issue being that there used, he did say they have been recently hydro tested. Should I be concerned buying a used tank? Also roughly how many top up fills would I get from a 12 litre 232 bar tank, filling 48ci tanks to roughly 2500-2800 psi?

Thanks

I love to voice my opinion

For the number of fills, this doesn’t give the right options, but is a really good guide. 

Second hand scuba will be fine, hydro tested shows it’s all good.  Just have a nose at the markings 

From new you have x years until it needs a test, then the test periods 

For second hand that’s the same, but if it was untested and had been sat depressurised and damp then a tester could fail it

I’m not fully on board for all scuba rules, they can have shorter test cycles (as they expect to keep breathing) but there have been the options of ‘surface use only’ markings - it that can be applied then you can have a longer cycle between hydro tests  

https://www.scubatoys.com/paintball/scubafills2.asp

The scuba sizes they list are in American, I think the ‘Scuba 80’ is equivalent to a 12 litre

A run through clicking the options will give a guide.  Whenever a fill level is higher than you want, just stop and you next fill will be able to get more

The highest it lets you choose is to refill at 1000, but in airsoft you should be using less air per shot than paintball, and can refill more often

(Always use the site air station when you can to save on your scuba - and if possible get a last fill before they shut it down at the end of the day)

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[Lockdown_Neil]

So my job is installing high pressure air systems for paintball and airsoft sites and everything Tommikka has said is bang on! 

There's not much I can add to this other than my advice which would be get yourself a 300bar 12ltr tank and fill from that, your'll get more fills for your money than a 232bar and it will last forever unlike these cheap compressors from China!  As a surface use mobile cylinder it's going to need a hydro test every 5 years which is going to cost you around £50 well looked after tanks rarely fail, as Tommikka said never leave them empty and NEVER leave the valve open. 

Get yourself a decent filling whip with a gauge if your worried about over filling as the small gauges on the bottles are rarely accurate, 3000psi working pressure bottles are tested to roughly 4496psi plus as stated you have a high pressure burst disc so it's not going to explode.

Lastly and it's been said already never ever get oil anywhere near the fill nipple, I'm an ex-paintballer and was at both the events Tommikka mentioned, one was in a Millennium event in Germany and the Southampton event was a friend of mine, I was standing about 10 meters away when it happened and lost my hearing in one ear for nearly a week, the guy had to have his playing jersey surgically removed from his skin as it had fussed itself to him, he's lucky to be alive.  

Ironically the team he played for was called '2 Hot for U'