Question Coltri Sub Cylinder Valves
- Thread starter Debesh Sanyal
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Snusmumrik
Contributor
AFAIK EU didn't demand the safety feature of a burst disc. So, don't keep your cylinders overfilled and store it away from direct sunlight.
It was a simple manufacturing error coupled with the stupidity of the importer and the exporter.
They made them for the American market with the American 3/4 NPSM thread. They then couldn't sell them to America due to not having a burst disc and therefore not complying with the USA DOT (Department of Transportation) regulations that mandate having a safety burst disc.
So next move you can guess is to sell them off cheap to a third world country with little or no regulations and it looks like they hit the jackpot in India with another idiot importer.
They couldn't sell into France or Germany or the UK or even their home town of Italy as we like India all use the metric M25x 2 ISO thread pattern that has a 5 degree difference in thread pitch angle a different thread pitch further with metric that doesn't match the American thread form in both angle and the numbers of threads per Inch. So depending if you fit them into steel of aluminium cylinders you get around six turns before either the steel cuts into the remaining thread of the brass plated pillar valve or with aluminium cylinders the plated brass cuts into the softer aluminium thread on the cylinder and they blast out explosively when being filled interestingly after about six to ten fills as the thread is so worn.
Now for India if the cylinder is stamped 3/4NPSM and the pillar valve also is stamped 3/4 NPSM then you should be OK with a couple of exceptions one is in that the American cylinder thread 0-ring groove is counterbored with a thinner 0-ring cross section than the M25x 2 thread form but India still also use the 3/4 BSPP Whitworth thread form and to add to your problems they even use the French M25 but with a thicker o-ring for the countersunk groove. Hence why if you are having to ask on an internet forum maybe better to leave well alone and avoid doing the "rounds" Buyer beware. And another reason why some tend to be a tad dismissive of Coltri abilities in the compressor market as well as the scuba.
Unless of course the purchase decision is based on how cheap.
They made them for the American market with the American 3/4 NPSM thread. They then couldn't sell them to America due to not having a burst disc and therefore not complying with the USA DOT (Department of Transportation) regulations that mandate having a safety burst disc.
So next move you can guess is to sell them off cheap to a third world country with little or no regulations and it looks like they hit the jackpot in India with another idiot importer.
They couldn't sell into France or Germany or the UK or even their home town of Italy as we like India all use the metric M25x 2 ISO thread pattern that has a 5 degree difference in thread pitch angle a different thread pitch further with metric that doesn't match the American thread form in both angle and the numbers of threads per Inch. So depending if you fit them into steel of aluminium cylinders you get around six turns before either the steel cuts into the remaining thread of the brass plated pillar valve or with aluminium cylinders the plated brass cuts into the softer aluminium thread on the cylinder and they blast out explosively when being filled interestingly after about six to ten fills as the thread is so worn.
Now for India if the cylinder is stamped 3/4NPSM and the pillar valve also is stamped 3/4 NPSM then you should be OK with a couple of exceptions one is in that the American cylinder thread 0-ring groove is counterbored with a thinner 0-ring cross section than the M25x 2 thread form but India still also use the 3/4 BSPP Whitworth thread form and to add to your problems they even use the French M25 but with a thicker o-ring for the countersunk groove. Hence why if you are having to ask on an internet forum maybe better to leave well alone and avoid doing the "rounds" Buyer beware. And another reason why some tend to be a tad dismissive of Coltri abilities in the compressor market as well as the scuba.
Unless of course the purchase decision is based on how cheap.
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