Diving tanks-at what pressure do you refill?

[Rapidnick]

As title. I'm interested to know how far 'down' you let the pressure drop in your tank before you take it in for a refill.

[MartynB]

As title. I'm interested to know how far 'down' you let the pressure drop in your tank before you take it in for a refill.

When I had a 232 bar tanks, I used to let it get to 180 as thet was the sweet spot back then. I disposed of that and got a 300 bar tank and get more fills

[Dodger21]

It really depends on the fill pressure of the rifle and howeasy it is to get to the refill centre but most guns will give you a reasonableamount of shots down to around 170 bar.

[mickmep]

usually run club ones down to between 170 and 160 bar before taking in.
lots of air arms shooters in club and they tend to fill to around 180 bar.

my personal one around 190 ish and it gets filled. its used for filling fac wolf which fills to 230 if available, local fill guy wont fill 7 litre from much lower, it makes his compressor too hot. took a bit of persuading to get him to fill from there, he sold me the bottle then decided he wouldn't fill them any more. don't use him any more. wouldn't bother taking a 12l in there so now go to closest dive shop for fills.

since getting more involved in the local club I tend to take mine and the clubs 2x12l ones in at the same time, so mine may well have a bit more in when it gets a top up.
my personal one went in for test Saturday, still had 200 bar in it, but club ones needed filling and saved a journey in a couple of weeks to take it on its own.

[Jesim1]

Much as above - I have a 300bar version, I don't see the point in 232bar cylinders for air guns as we are only interested in the high end pressure, so by 170/160 you really need it filled again.

So 170 - 230bar on a low pressure cylinder means your getting about 60bar worth of use at however many litres your cylinder is, on a 300 bar filled to say 290 your getting 170 - 290, so typically double the use regardless of your size of cylinder as long as you compare like for like sizes.

James

[angrybear]

As title. I'm interested to know how far 'down' you let the pressure drop in your tank before you take it in for a refill.

Note the pressure at which your rifle's POI starts to drop & add 30-40bar (enough shots for a hunting trip) to that as a minimum.

So as my rapid's fine down to 120bar, once the refill pressure equalises at 150bar ish then it's time for a refill.

[where's it gone]

If I'm refilling a rifle, and the max on rifle is 200 bar, I'd would need the diving tank to have at least this pressure in it. Yes I know I'm wasting money because I pay the same for a refill on D/T to 300 bar as if the D/T is near empty. But then again, I want to fill my rifle not top it up partly.

[angrybear]

If I'm refilling a rifle, and the max on rifle is 200 bar, I'd would need the diving tank to have at least this pressure in it. Yes I know I'm wasting money because I pay the same for a refill on D/T to 300 bar as if the D/T is near empty. But then again, I want to fill my rifle not top it up partly.

Daft, but entirely up to you.

Better to know the sweet spot & only fill to that upper level

[RobF]

Daft, but entirely up to you.

Better to know the sweet spot & only fill to that upper level

If your rifle has a sweet spot. If regged it may not, then it's a case of shot count.

[SuffolkRifle]

I usually get them refilled when they get to about 180 bar (got two, a 3 litre and a 12 litre), the guns we have aren't regged, but will shoot accurately down to 150 bar, but as we shoot target, we 'need' 30 shots, and a 180 fill just about does that. We're lucky in that our local dive shop is only about a fiver for a 12l fill, less for a 3l

[Rapidnick]

Thanks for your contributions guys. I use both regged and unregged rifles (all my pcps are Rapids) but as the regged one is legal limit and can be charged up to 230BAR and gives me loads of shots it gets used quite a lot more than the fast flow FAC. My FAC rifles have pressure gauges so I get a visual guide as to when recharging is necessary. The regged rifle goes 'off the reg' at 100BAR whereas the FAC fast flow starts to droop just a bit above that although the power curve is very small and the POI remains pretty constant throughout the range. I also prefer the smaller 280cc bottles for better handling and accept the lower shot count.
Anyway it seems that refilling the main tank when it reaches 170 BAR is a pretty good compromise so that is what I tend to do. My tank is a 12 litre 300 BAR steel Faber model and I get it charged at a facility near my club for a fiver. Although they tend only to charge to 270BAR once the cylinder has cooled down. However their service is excellent and as around me the dive shops all seem to be having problems with their 300BAR compressors that will do for the moment.

[MartynB]

I usually get them refilled when they get to about 180 bar (got two, a 3 litre and a 12 litre), the guns we have aren't regged, but will shoot accurately down to 150 bar, but as we shoot target, we 'need' 30 shots, and a 180 fill just about does that. We're lucky in that our local dive shop is only about a fiver for a 12l fill, less for a 3l

Diveline ?

[krisko]

if you are only benchrest shooting, actually you can have the cylinder tethered and shoot it all the way down to 90bar or whatever is the point where the power drops off.
that's lot more, many many shots.

if hunting and lazy refilling often, sure you get a 300bar cylinder and you fill to the max working pressure of the gun/cylinder again if unregulated it will be the higher point of the plateau.

fill places don't like filling completely empty cylinders. also it will warm up lot more when more volume/ air needs to enter the cylinder.

[lensman57]

As title. I'm interested to know how far 'down' you let the pressure drop in your tank before you take it in for a refill.

Mine is a 300 bar tank and I usually call it a day when it hits around 160. You see it would not do much for my HW 100 but it can still fill my S400, Regal XL and BSA r10 for a couple of fills before it becomes really useless. I only wish that the re-fill would be a proper one to 300 which it seldom is.

A.G

[angrybear]

If your rifle has a sweet spot. If regged it may not, then it's a case of shot count.

True enough.