^mimic^ Posted December 13, 2005 Report Share Posted December 13, 2005 (edited) Hi all, A subject has come to mind that i would like to find out more on. I recently read of some problems with divers bottles... a lad with 18 month old cylinder , failed its test now i understand that these things do wear out, but this seemed to me to be an extreamly quick time for something to become unsafe, i have known bottles to last many more years than this. It was explained on the thread that hydrolic testing does weaken the bottles , this i do accept But i have known many bottles put up with a hell of alot more tests than that. mine is pritty old an been tested many many times. This has rasied a Red flag Something must have damaged that tank, and i dont think it was the hydrolic tests Two things spring to mind Salted or saline air (seaside air) or Damp air , and i wonder does presure affect the rate at wich things corrode?? now to the tittle PCP tanks.... if it did that to his Divers bottle in that little time then what the hell did it do to the inside of his gun? I am conserned because i see apparent wisps of What apears to be a grey vapour when i fire my guns, and im conserned something bad maybe happening inside With there being nothing more than the orginal manafactures test verification for the guns PCP tanks I find myself wondering just how safe are these things? Edited December 13, 2005 by ^mimic^ Quote Link to comment Share on other sites More sharing options...
The Shootist Posted December 13, 2005 Report Share Posted December 13, 2005 a lad with 18 month old cylinder , failed its test Why would an 18 month old cylinder be tested ? Cylinder doesnt need a hydraulic test till it's 5 years old ! There is an intermediate test for non surface use bottles but thats visual only and not required for airgun bottles anyway. Something fishy in that story... Tony Quote Link to comment Share on other sites More sharing options...
1 of 5 Posted December 13, 2005 Report Share Posted December 13, 2005 If you read the story carefully on the failed bottle you'd know that the person had owned the bottle for 18 months, NOT that it was 18 months old. ie he bought it secondhand and it was of indeterminate (from the story) age. Quote Link to comment Share on other sites More sharing options...
^mimic^ Posted December 13, 2005 Author Report Share Posted December 13, 2005 (edited) Well thats alot less worrying, as the bottle could have been any age....... but i must ask why is an airgun bottle be treated diferrent when it comes to testing? surely there is a set standard for all divers bottles? Edited December 13, 2005 by ^mimic^ Quote Link to comment Share on other sites More sharing options...
The Shootist Posted December 13, 2005 Report Share Posted December 13, 2005 but i must ask why is an airgun bottle be treated diferrent when it comes to testing? surely there is a set standard for all divers bottles? There is a set standard for all divers bottles... A hydraulic test every 5 years... plus an additional visual inspection between times for bottles that are used submerged... ie for diving. The intermediate visual inspection is not required for bottles that are surface use only... Presumably a corrosion check because of salt water contact and not needed for a bottle kept dry. Tony Quote Link to comment Share on other sites More sharing options...
Axe Posted December 13, 2005 Report Share Posted December 13, 2005 Wouldnt the visual inspection be done on each refill anyway?! Quote Link to comment Share on other sites More sharing options...
SNAKEBITE Posted December 13, 2005 Report Share Posted December 13, 2005 Having thought about this I have come to the conclusion that seeing as none have reported to have blown up (apart from the Rapid in Ben Taylors work shop that was filled with an unpecified gas) that all is fairly safe. However if a gun is charged with a foot pump then over a long period of time corrosion could affect the integrity of the resevoir and problems could arise. Obviously dry air would not be a problem. Are we sitting on "time bombs" or am I just thinking too deeply? Quote Link to comment Share on other sites More sharing options...
ROB REYNOLDS UK Posted December 13, 2005 Report Share Posted December 13, 2005 well im like a few on here im in to my scuba diveing and we learn all about them bottles they are a bomb ready to go off if you abuse them ,now if you were next to a car tyre that went bang you would jump out your skin and thats only 32psi now the bottles i use are 12ltr 300 bar thats around 4,250psi and if that was to go off i think you would be looking for the body parts for some time its just as well they wont fill them bottles with out a test Quote Link to comment Share on other sites More sharing options...
Axe Posted December 14, 2005 Report Share Posted December 14, 2005 (edited) Ive been around divers tanks for many years and know what sort of damage an exploding tank would cause. A friend of mine worked for Hales replacing the truck tyres on the class 2 & 3 skip trucks. He saw a guy loose his hand from a blister on the sidewall popping. These truck tyres pump over 100 psi, nasty! Wasnt there a picture posted a while back, of some blokes car having been the recipient of a divers tank that had exploded, a real mess. Always make me think when recharging my buddy bottle and especially when I have the rifle to the shoulder. Edited December 14, 2005 by Axe Quote Link to comment Share on other sites More sharing options...
1 of 5 Posted December 14, 2005 Report Share Posted December 14, 2005 The exploding bottle is here http://www.diveshop-pr.com/pages.dir/engl....kexplosion.html Quote Link to comment Share on other sites More sharing options...
24joy Posted December 14, 2005 Report Share Posted December 14, 2005 Just a piont to add. When having your bottle recharged, it doesn't hurt to ask if the compressor is filtered correctly. These can be very pricey, and need to be changed on a regular basis, hence your fee for air. Rubber boots on the bottom of a bottle can be a course to unwanted corrosion in that miosture can be trapped Quote Link to comment Share on other sites More sharing options...
rarms Posted December 14, 2005 Report Share Posted December 14, 2005 ^mimic^ Where abouts in worthing are you? Quote Link to comment Share on other sites More sharing options...
^mimic^ Posted December 15, 2005 Author Report Share Posted December 15, 2005 (edited) However if a gun is charged with a foot pump then over a long period of time corrosion could affect the integrity of the resevoir and problems could arise. Obviously dry air would not be a problem. Are we sitting on "time bombs" or am I just thinking too deeply? It pays to think when dealing with 3000psi, Time bomb isnt a bad way to put it They must have a shelf life, like anything , the question is how long?. How quickly could wet salt air or bad air corrode a gun?. if its second hand whos to say what quality air its had?. One anser is certain I dont want to be on the business end of a tank falure Edited December 15, 2005 by ^mimic^ Quote Link to comment Share on other sites More sharing options...
^mimic^ Posted December 15, 2005 Author Report Share Posted December 15, 2005 well im like a few on here im in to my scuba diveing and we learn all about them bottles they are a bomb ready to go off if you abuse them ,now if you were next to a car tyre that went bang you would jump out your skin and thats only 32psi now the bottles i use are 12ltr 300 bar thats around 4,250psi and if that was to go off i think you would be looking for the body parts for some time its just as well they wont fill them bottles with out a test No they wont fill our bottles without a test , But We fill our guns and that is exactly what im getting at there is no test for the gun , now i know the pcp tank isnt as big and isnt gunner do as much damage but i reacon it could atleast blow off a hand or posibly worse Quote Link to comment Share on other sites More sharing options...
1 of 5 Posted December 16, 2005 Report Share Posted December 16, 2005 Some guns simply can't be tested. AA cylinders have an exgineered in weak spot at the threads. At 250 bar or thereabouts they blow in a controlled manner which whilst it may well fill your pants won't do you any harm. The Hornet could be tested but was destruction tested when designed and didn't blow until 12000psi. Quote Link to comment Share on other sites More sharing options...
deadeye ive Posted December 16, 2005 Report Share Posted December 16, 2005 now i know the pcp tank isnt as big and isnt gunner do as much damage but i reacon it could at least blow off a hand or possibly worse If this were the case what do you think would happen to the PCP business overnight These guns are designed by very clever engineers ...Have you seen a risk assessment for working off step ladders .........Imagine the one engineers face when designing LIGHTWEIGHT Cylinders with a 200 bar working pressure. Just don't fill with Oxygen or even Hydrogen :thumbs: Gas Bottles have a shelf life .They corrode and so are designed to heavy weight construction to allow for this hence the regs saying they should be checked at certain intervals of their life . Pcps have no such regs and as already been mentioned safety devices have already been put in place.................. If there was a problem with PCPs and corrosion we'd have heard something by now .........Stop worrying and shoot the Bloody Thing Welcome back Mimic ........You seem to have gone all sensible Ive :thumbs: Quote Link to comment Share on other sites More sharing options...
^mimic^ Posted December 16, 2005 Author Report Share Posted December 16, 2005 (edited) may well fill your pants won't do you any harm. *****, only your pride Welcome back Mimic ........You seem to have gone all sensible Give it time Edited December 16, 2005 by ^mimic^ Quote Link to comment Share on other sites More sharing options...
Cranfield Posted December 17, 2005 Report Share Posted December 17, 2005 Welcome back Mimic ........You seem to have gone all sensible Give it time Few people get a second bite of the cherry, nobody gets a third. Just thought I'd mention that. Quote Link to comment Share on other sites More sharing options...
P03 Posted December 20, 2005 Report Share Posted December 20, 2005 Wouldnt the visual inspection be done on each refill anyway?! All diving cylinders are subject to a visual inspection every 2 1/2 years this is an INTERNAL inspection where the valve is removed and an endoscope is used to do the inspection They also need a hydraulic test every five years as previously stated. The main cause of deterioraton in diving cylinders is storing them empty with the valve open this allows damp air inside and corrodes the inside, however, the hydraulic test checks for the expansion of the cylinder under pressure the permissible expansion being +5% of the un-expanded circumferance. PS aluminium cylinders tend to corrode a lot faster than steel anything made by Luxfer is aluminium) P03 Quote Link to comment Share on other sites More sharing options...
roblade Posted December 21, 2005 Report Share Posted December 21, 2005 All diving cylinders are subject to a visual inspection every 2 1/2 years this is an INTERNAL inspection where the valve is removed and an endoscope is used to do the inspection They also need a hydraulic test every five years as previously stated. As far as im aware and this is from a guy that dives as well as works at a fill centre, as long as the bottle is clearly marked "FOR SURFACE USE ONLY" or words to that effect, it only requires the 5 year test and NOT the visual test every 2.5 years. ROB Quote Link to comment Share on other sites More sharing options...
P03 Posted December 21, 2005 Report Share Posted December 21, 2005 Not sure on that one P03 Quote Link to comment Share on other sites More sharing options...
1 of 5 Posted December 21, 2005 Report Share Posted December 21, 2005 (edited) All diving cylinders are subject to a visual inspection every 2 1/2 years this is an INTERNAL inspection where the valve is removed and an endoscope is used to do the inspection They also need a hydraulic test every five years as previously stated. As far as im aware and this is from a guy that dives as well as works at a fill centre, as long as the bottle is clearly marked "FOR SURFACE USE ONLY" or words to that effect, it only requires the 5 year test and NOT the visual test every 2.5 years. ROB Not in my experience Rob. Robin Hood Watersports will simply not accept that as proof the bottle hasn't been underwater. The only bottles they accept with a 5 year test span are those with an airgun valve. ie the valve on the bottle has a built in gauge thus rendering it unuseable underwater. Edited December 21, 2005 by 1 of 5 Quote Link to comment Share on other sites More sharing options...
The Shootist Posted December 21, 2005 Report Share Posted December 21, 2005 Both the dive shops I use ... Letchworth and Chelmsford are quite happy with a sticker on the bottle 'Surface use Only' and my bottle has the diving style valve... So whilst surface bottles are exempt from the visual test... it seems it's down to the individual dive shop as to what they accept as a surface bottle... Tony Quote Link to comment Share on other sites More sharing options...
SNAKEBITE Posted December 21, 2005 Report Share Posted December 21, 2005 How much does a test cost, and what is involved? Quote Link to comment Share on other sites More sharing options...
Lord Geordie Posted December 30, 2005 Report Share Posted December 30, 2005 a lad with 18 month old cylinder , failed its test Why would an 18 month old cylinder be tested ? Cylinder doesnt need a hydraulic test till it's 5 years old ! There is an intermediate test for non surface use bottles but thats visual only and not required for airgun bottles anyway. Something fishy in that story... Tony I was told a visual after 18 month and then a hydro test after 36 on a brand new bottle i just bought and that was from the Dive Centre in newcastle I thought it depended on the Valve (surface or water) but i was told there is NO difference they BOTH need testing at 18 month intervals and then the 36 month hydro. I was told a tank with a SURFACE valve was only tested every 5 years but now i am unsure??? Lord Geordie Quote Link to comment Share on other sites More sharing options...
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