What about this idea for a gas bottle aux receiver ?

[MattF]

...and have a thicker wall

Not compared to an old IR, and possibly similar tanks, they don't. I seem to recall they used 1/4" steel on their tanks. Stupidly heavy for their size they are.

 

[CompoSimmonite]

Not compared to an old IR, and possibly similar tanks, they don't. I seem to recall they used 1/4" steel on their tanks. Stupidly heavy for their size they are.

I must admit I've got a good 100 ltr Ingersol Rand tank (free to anyone who wants it ) and it's heavier than a 47kg gas bottle.

 

[CompoSimmonite]

I have problems (mental as well as physical) with going out so tend to buy as much as possible via the web. The other day shopped around for cheapest set of fittings I'd need to "experiment" with this idea then decided to look on eBay.
What is shocking is it's actually far cheaper to buy from China than UK plus free P&P. Ok you might say "Chinese quality ! " but being realistic I bet a lot of the cheap fittings available by mail order from UK suppliers, and also from visits in person to engineering merchants, are sourced in China

 

[rtbcomp]

..........but being realistic I bet a lot of the cheap fittings available by mail order from UK suppliers, and also from visits in person to engineering merchants, are sourced in China

I agree, I bought some lever operated ball valves from two sources in the UK, one mail order the other over the counter; they turned out to be made by Jushui http://www.made-in-china.com/showroom/393665155 and they are indeed rubbish. After about 20 operations excessive play develops between the handle and the ball, meaning they don't close properly.

 

[CompoSimmonite]

I agree, I bought some lever operated ball valves from two sources in the UK, one mail order the other over the counter; they turned out to be made by Jushui http://www.made-in-china.com/showroom/393665155 and they are indeed rubbish. After about 20 operations excessive play develops between the handle and the ball, meaning they don't close properly.

I have had a pair of ball valves delivered today. Made in Italy and look / feel good quality. Only £5 inc P&P for the 1/2" -
http://www.ebay.co.uk/itm/121507248...49&var=420443605273&ssPageName=STRK:MEBIDX:IT

 

[rtbcomp]

Thanks - I'll bear that in mind. I now buy them from my local DIY shop. They have small levers on them (like washing machine taps) but I fitted the longer levers from the Chinese ones. They were about £2.00 each.

The Chinese ones looked & felt ok, it's just poor quality materials that wears very quickly.

 

[Burdekin]

For interest calculated the minimum shell thickness for 10bar and 8bar pressure of a 47kg propane tank. Used 40000psi as the maximum allowable stress (I assumed this as I couldn't find a definite figure on the net) and a joint efficiency of .8, worked out at 0.9mm for 10bar and 0.7mm for 8bar. In reality it is probably lower but the issue then becomes lack of mechanical strength.

Also bleach does seem to get rid of the smell in propane tanks. I cleaned one with degreaser, rinsed, then swirled some bleach in, then added bicarb soda and three dishwasher tablets, let soak for a coup!e of days, then rinsed, swirled in more bleach, rinsed and let soak with water and there was no smell.

 

[rtbcomp]

Bear in mind bleach is corrosive. The smell will go away with a few days use anyway.

 

[Burdekin]

I should have said I filled with water after adding the bleach, bicarb and soap tablets.

 

[Bill Edwards]

A squirt of washing up liquid, then the hosepipe to fill and mix with the washing up liquid at the same time. Then when it's full tip it over and let it drain.

 

[normspanners]

from a previous thread

But one other way would be to have the tee as said but have a smaller dia say 15mm pipe with its own smaller tee straight through the first tee and up into the cylinder about half way, that would be the draw off for the airbrush, then in the centre of that a 10mm pipe that would be the feed from the compressor going all the way to the top that way the warm air would be fed in though the btm but the air would come out at the top, the drawn air would be fed from the middle, the driest place, any condensate would collect at the bottom and be drained out of the side of the first tee with a valve you could even use the original valve as a drain point screwed into the tee, the air for the air line would be fed from the side of the second smaller tee and feed pipe would go in the very bottom.
That way it can be done with just screwed together galv fittings and no need to weld the cylinder.