Lightweight cylinder HW 100 carbine recommendation

[Goatofmendez]

So the three of us who saw this know that the member it happened to is a skilled engineer of many years standing, and you are suspicious of the posts we have made?? The wall thickness at the point of fracture is less than 3mm.
Come and have a look if you don't believe us.

Merry Christmas.....

Exactly, the claims simply do not make sense. E.g. the ends are designed as standard HW100 ends and as such the part of the cylinder internally that the o-ring sits on is 30mm. The OD of the tube is 37mm. So 37mm - 30mm = 7mm. Divide that by 2 for the wall thickness = 3.5mm MAXIMUM. So the wall thickness cannot be 4.3mm at it's thinnest part.

[Goatofmendez]

They are cheaper to get, that’s why. Welded aluminium tubes are also common.
Everybody knows how to milk the hobbyist.

Not in high pressure tubes. You are talking absolute rubbish.

[NickG]

Exactly, the claims simply do not make sense. E.g. the ends are designed as standard HW100 ends and as such the part of the cylinder internally that the o-ring sits on is 30mm. The OD of the tube is 37mm. So 37mm - 30mm = 7mm. Divide that by 2 for the wall thickness = 3.5mm MAXIMUM. So the wall thickness cannot be 4.3mm at it's thinnest part.

forget the major diameter of the internal thread is even larger , if its a 1mm pitch (a guess as I haven't measured one but would assume a fine thread ) the thread depth will be in the region of 0.8mm so that makes a wall thickness of 2.7mm not a lot when you think about it .

[Willsinker]

forget the major diameter of the internal thread is even larger , if its a 1mm pitch (a guess as I haven't measured one but would assume a fine thread ) the thread depth will be in the region of 0.8mm so that makes a wall thickness of 2.7mm not a lot when you think about it .

Fenton’s attitude to this issue is quite disturbing. It’s reminiscent of a green grocer reacting to a complaint of blighted Maris Pipers.
Taking pride in one catastrophic failure out of only 100 units sold (actually 101 if Luftgewehr’s recently inspired purchase is included), betrays a somewhat bewildering grasp of the situation. I doubt Rolls Royce would be so sanguine if one in every 101 jet engines consumed themselves so dramatically. Exactly how many of these potential pipe bombs are yet to explode remains to be seen. Should there be another, let’s hope the photographs don’t include severed digits or someone’s gonads imitating a testicle smoothie!

Until the root cause of this failure is determined all devices using this cylinder should be treated with extreme caution. However, following the complaint, no attempt was made to retrieve the failed part for analysis. Instead, speculation appears to be the preferred method of investigation; resulting in a meaningless paper shuffling exercise, amounting to nothing more than facile window dressing, in a feeble attempt to ‘mitigate risk’ and protect the ‘airgun community’.

[I. J.]

As stated in my earlier post (# 32) the owner of this failed HW100 cylinder is not a member of this or any other airgun forum. He has passed me the following message:

'I will release the offending tube to someone who will carry out an inspection and analysis of the tube. This must
not be anyone who has any affiliation to the supplier. '.

ATB
Ian

[Bladerunner too]

As stated in my earlier post (# 32) the owner of this failed HW100 cylinder is not a member of this or any other airgun forum. He has passed me the following message:

'I will release the offending tube to someone who will carry out an inspection and analysis of the tube. This must
not be anyone who has any affiliation to the supplier. '.

ATB
Ian

Now,i applauded the above statement when i read it , i agree the tube does need looking at by an expert, (that puts me out) wonder what the cost would be?

[I. J.]

Now,i applauded the above statement when i read it , i agree the tube does need looking at by an expert, (that puts me out) wonder what the cost would be?

That has got to be one of the conditions to be agreed between the owner of the damaged cylinder and the prospective examiner.

ATB
Ian

[jepho]

So what is the maximum MPa for 6082T6 Aluminium?

Still can't understand why the tube went pop at 150bar though. Also is it legal to send compressed air cylinders in the post? What postal method do you use?

thanks

This thread was a great public service announcement to people who are (like me) considering the various options for cylinder and regulator upgrades to my HW100.

Any failure of a pressure component at only 75% of its nominally rated use pressure; must be completely unacceptable. If the item has failed at 25% less than its rated use parameters, it implies both poor construction and inadequate testing. Any engineering environment would hang its company head in shame if this sort of failure became known outside of the company.

Removing all of the personalities involved (I don't know any of them and it just serves to cloud the issues) I would defy anyone to justify producing vital components that fail with much less than normal use. Where components are crucial to the operation of the equipment and failure is dangerous, the components must be over-engineered and fitted with a degree of redundancy to prevent harm to individuals using the equipment. Anything less displays a cavalier disregard for the continuing good health of the user.

It is incumbent upon the manufacturer to instantly cease all sales of the 'upgrade' until the issue of cylinder collapse for reasons unknown has been independently examined, analysed and fixed. Anything less is to ignore the potential harm which may be caused to purchasers by another random and unexplained cylinder failure. The glib assurances from the supplier are not convincing. They make me want to keep well away from the company's products for all time. I will not be rushing out to purchase a cylinder; as a sign that I believe in the open and honest approach of the company; as supposedly demonstrated in this thread.

The best case I can ascribe to this event is that the company are absent-mindedly foolhardy. The worst case does even not bear thinking about.

It has been very worthwhile for me to join the forum. It has permitted me to follow this dangerous and distressing and event and to read the excellent responses to the manufacturer; who to all intents and purposes appears to be oblivious to the potential for future harm being caused by the company's similar products on offer. My new membership of AirgunBBS has saved me money and possibly my hands, eyes or worse. Thank you all members who contributed to a really informative thread.