Compressor Air Receiver

But I'd guess you have a suitable compressor?

You tend to be rather more carefull with those though. You don't want to be in the same room as an air compressor tank failing, you don't want to be in the neighbouring room when a gas cylinder fails.

Fortunately cheap compressors normally stop working a long time before any likelihood of tank failure.

The message from "JonnyBoy" contains these words:

eBay Item number: 7977804206

The message from "Tim.." contains these words:

Is that a euphemism for "refilling the teacup"?

But you didn't buy a suitable compressor? Which can cost a great deal if it allows continuous use - as most electric tools do.

Fine if you only want to use them close to your compressor. But many DIY power tools won't just get used in the garage.

Sure, if that's what their operating pressures are.

Yes, but presumably they are made to stand this. I wouldn't want to put 300 bar into a cylinder made to accept say 20 bar even if it was 'only to run a grinder'.

Rob

Is that a known statistic, then?

Rob

I'm extrapolating from the dozen or so I've got through. The larger ones (Atlas Copco/Hydrovane) last forever , the italian ones rarely seem to last more than a couple of thousand hours & the tanks haven't even started going rusty. I don't think I've ever even heard of a small compressor actually having the tank condemned.

Somebody must sell them, they used to advertise on TV all the time when I was in Italy. Of course if you want a cheap tank then 7521037899 isn't going to fetch much.

Yes, the cost of air tools and a compressor to go with it is much better than buying all the equivilant tools in electric format.

This all came about as I was hunting an electric Die Grinder for ages. Ebay, they were going for £75 upwards for second hand ones!

Good electric die grinders always have been expensive. As opposed to cheap air grinders, they are precision tools. Usually running at much higher revs. The Bosch die grinder I have runs at 65,000 revs. Ideal for very small grinding burrs, but near £300 to buy new. But, as has been said, horses for courses. If you don't need that sort of accuracy the cheap £10-20 air ones are perfectly OK. I have one myself, which I use for rough work. Takes stones or burrs with a 6mm dia shank, which is useful. Maximum in the Bosch is 3mm. Mike.

Fortunately I don't think I've met a dive shop cowboy enough to do that :-) Fortunately there's an overpressure valve that should pop first.

AFAIK dive cylinders have two pressures marked on them - WP and TP. These are reputed to stand for 'Women's Pressure' and 'The Pressure' :-)

cheers, clive

You miss my point. I'm not saying the diving cylinders are over-pressurised. I'm saying that 300 bar in a 20 bar cylinder isn't something I'd want to do.

Rob

I'd guessed that :-) The over pressure pop outs make one hell of a noise when they go.

I've never actually seen or heard a dive cylinder go bang, but I have seen the aftermath and it ain't pretty!

When the cylinders are being pressure tested, the dive shops use hydraulic testing, so if one does burst, you get a bit wet, but there's no danger. Supposedly...

BTW, most "cooking" dive cylinders are rated at 232 bar working pressure, and IIRC 320 bar test pressure (I can't be 100% sure on the TP, I sold my cylinders a couple of years ago).

There are some "high pressure" dive cylinders, which IIRC are 300 bar WP and over 400 bar TP...not for me thanks! My wife used to have a couple of 4l pony tanks as a twin set and they were 228 bar - they're the only dive cylinders I've ever come across with that WP...

Z cylinders are now available at 300 bar. Although if you're using Zs then you're probably aware of this & unlikely to screw a 230bar regulator into them

I have a couple (at least one, I think two) pub gas cylinders buried in the long grass in the garden that I don't want any more if you are anywhere near Essex.

I've always been a shade nervous with around 150 psi sitting in the tank on the commercial size compressor I was given. Does anybody know what it costs to get these things pressure tested? I'd be gutted if the tank was condemmed but I guess I'd be equally gutted in a different way if the thing exploded.

I rescued one from work last year that was being thrown out after the tank had been condemned. It was one of those hugely expensive quiet running jobs. The tank's inspection plug had been removed to stop anyone using it and the inside was a horrible mess despite looking sound from the outside. I blame the water drain tap, which instead of being at the bottom, was at the top with a tube down to the bottom, so it would only work under pressure. Daft. I reckoned I could find a use for the compressor without the tank, but ended up giving it to a friend with the same idea.