Forum sponsored by:

gas tank construction

Search for: in Thread Title in

Dougie Swan	06/01/2011 20:42:47
269 forum posts 73 photos	Thanks to all who posted replies to my request for gas tank filler valves The thread went well OT towards the end but it was interesting all the same. My next question regards the tank itself, and what sort of pressure I should test it to? The commercial ones I have seen say they have been tested to 300 odd psi, is this what I need to achieve? If so what guage of copper tube will I need? I was planning to use an offcut of 2.5" which has a wall thickness of 1mm or so. With the pressures above it seems unlikely that my tank will survive the test. Any thoughts/help will be greatly appreciated Dougie Swan Edited By Dougie Swan on 06/01/2011 20:56:34
James fortin	06/01/2011 21:20:09
46 forum posts 12 photos	i dont know if this will hep but 'pure copper in its cast form has a tensile strength of around 125n/mm² though drawing increases this to 275n/mm² from; 'workshop materials by alex weiss' james
John Olsen	06/01/2011 21:48:57
1294 forum posts 108 photos 1 articles	This would be drawn tube so the higher figure would apply. A rough calculation suggests a bursting pressure for that tube of over 1000 psi, so a working pressure of 150 (for propane) with a test pressure of twice that would actually look OK.Since you would probably use butane the safety factor would be even higher. The general idea is as with boilers, you design for a generous safety factor, typically 8 times. Then you test to say twice (sometimes 1.5) times working pressure. The idea is to discover any leaks or major problems, without overstressing the vessel such as to create them. It does not pay to over test, since stressing to near the limits could cause damage that will cause problems later. If you are in a club, it might pay to talk to the boiler committee. regards John
Terryd	06/01/2011 22:02:30
1946 forum posts 179 photos	Hi There, Dave Watkins built a small model De Winton type loco and eventually made a gas burner and gas tank for it. It is detailed here and may give you some pointers. Scroll down about 2/3 of the way down the page and look for the 'Idris Story'. There are complete drawings as well to download for free. Let us know how you get on. Beast regards Terry
Martin W	06/01/2011 23:16:16
940 forum posts 30 photos	Terry Can't get your link to work under 'It is detailed here ...'. Is the link OK or is it me and my system? Cheers Martin PS Like the typo in your salutation .
Terryd	07/01/2011 09:28:04
1946 forum posts 179 photos	Hi Martin, It appears to be the link in the original posting, why that is I'm not sure it's never happened before . Try again here. It appears to be working now. The links to the 'Idris Story' and drawings are about 2/3 of the way down the page beneath a picture of the loco. regards Terry Edited By Terryd on 07/01/2011 09:30:34
Terryd	07/01/2011 10:12:16
1946 forum posts 179 photos	Hi there, the drawing for the butane gas tank is here and the gas regulator here. the latter is a variation of the boiler regulator (see notes on drawings). Hope this helps, Terry
Dougie Swan	07/01/2011 15:37:11
269 forum posts 73 photos	Thanks for the above, it has helped a lot I have alo seen advertised "gas filler nozzles" not the same as the fill valve on the tank but something that looks like it would fit onto the top of a blowlamp gas canister. Are these used to fill the gas tank from a blowlamp refill? Once again any info would be very welcome If anyone is interested, I have posted a couple of pics of the engine that will be powered by the gas boiler under construction. It's still very much a work in progress but any thoughts/comments are welcome Thanks Dougie Swan
Terryd	07/01/2011 17:01:48
1946 forum posts 179 photos	Hi Dougie, Not sure about the proposed filler valves/nozzles but I did notice that on Dave Watkins detailed description of building Idris and burner he did describe methods of pressure testing. I thought that may be of use to you. Regards, Terry
Dougie Swan	07/01/2011 17:19:26
269 forum posts 73 photos	Hi Terry Yes it was, that information and some of the replies above made me feel a lot better about tesing to 300psi. I liked Dave's design of regulator and might try it The filler valve I'm referring to looks like it screws onto a blowlamp fitting and has a length of copper pipe sticking out there is one on ebay and another sold by Bruce Engineering, it's just the use I'm not sure of Regards Dougie
Richard Marks	07/01/2011 17:58:08
218 forum posts 8 photos	Gentlemen Please enlighten me, I dont dispute any statement regarding the working pressures stated for our friends gas tank but the aerosol and gaz canisters I have handled have been made tinplate or aluminium, neither canister capable of handling 300psi,is it me or am I missing something? Regards Dick
mrsgoggins	13/01/2011 15:34:38
2 forum posts	Dick, The answer lies in the controls over material properties, the manufacturing process and the filling ratio. Steel and aluminium are much stronger than copper when selected and processed correctly, (eg not subjected to uncontrolled heat treatment) and safety factors can be lower because of the level of control. Disposable gas canisters are for single use only and do not need to include a fatigue allowance in any safety factors. Keith
Ian S C	14/01/2011 09:35:34
7468 forum posts 230 photos	There have been articals on pressure testing disposable gas cylinders to destruction, by lighting a fire under the cylinder(with gauge), an retreating to a safe distance with a pair of binoculars, don't remember the pressures reached, but it was considerable, getting up 400psi+. Ian S C
Gordon W	14/01/2011 09:51:49
2011 forum posts	Pressure testing is simple and safe, just fill with water, or similar, make sure everything is filled with water, pump up to required pressure. Any leak and pressure drops immediatly. Anybody interested in pressure vessels should look at the plastic lemonade bottles, a work of art IMHO.

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts

*Oct 2023: FORUM MIGRATION TIMELINE*
05/10/2023 07:57:11
Making ER11 collet chuck
05/10/2023 07:56:24
What did you do today? 2023
05/10/2023 07:25:01
Orrery
05/10/2023 06:00:41
Wera hand-tools
05/10/2023 05:47:07
New member
05/10/2023 04:40:11
Problems with external pot on at1 vfd
05/10/2023 00:06:32
Drain plug
04/10/2023 23:36:17
digi phase converter for 10 machines.....
04/10/2023 23:13:48
Winter Storage Of Locomotives
04/10/2023 21:02:11
More Latest Posts...
View All Topics

Support Our Partners

Shopping Partners

Subscription Offer

Latest "For Sale" Ads

Reeves** - Rebuilt Royal Scot by Martin Evans
by John Broughton
£300.00
BRITANNIA 5" GAUGE James Perrier
by Jon Seabright 1
£2,500.00
Drill Grinder - for restoration
by Nigel Graham 2
£0.00
WARCO WM18 MILLING MACHINE
by Alex Chudley
£1,200.00
MYFORD SUPER 7 LATHE
by Alex Chudley
£2,000.00
More "For Sale" Ads...

Latest "Wanted" Ads

D1-3 backplate
by Michael Horley
Price Not Specified
fixed steady for a Colchester bantam mark1 800
by George Jervis
Price Not Specified
lbsc pansy
by JACK SIDEBOTHAM
Price Not Specified
Pratt Burnerd multifit chuck key.
by Tim Riome
Price Not Specified
BANDSAW BLADE WELDER
by HUGH
Price Not Specified
More "Wanted" Ads...

Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues