Propane tank receiver

[normspanners]

I think I remember that, with the size of the thread in the top of a tank it would be quite restrictive.

no you only need a very small drain pipe brake pipe would do, but the 47kg are 3/4 bsp anyway.

 

[MattF]

Didn't know it was considered a safe thing to do, thanks.

They should, if doing things by the book, be pressure tested after making any physical alterations to the tank.

 

[addjunkie]

They should, if doing things by the book, be pressure tested after making any physical alterations to the tank.

Hydrotested....pressure testing with gas / air is much much more dangerous. From memory it "should" be a strength test to 150% of MAWP.

If you have a good look at any pressurised container you should find the origional test details on it somewhere.

 

[Wendelspanswick]

The propane can even contaminate the metal

Any scientific proof of this or is it just internet gossip, I'd be interested in seeing the paper?

 

[Kayos]

My thought has always been to make a frame to stand it upside down, no welding needed on the tank

 

[rtbcomp]

The HSE bloke told me it was OK to use propane/butane bottles for compressed air as long as they had a test certificate.

I had about a dozen connected together, mounted upside down with a water trap on the common pipe between the compressor and the tanks. This caught moisture on its way into the tank and any that condensed inside the tank coming back out.

Given my welding skills there was no way I was going to attempt making an airtight weld. On butane tanks I removed the valve, drilled through it and soldered some 15mm copper pipe in place, with the propane tanks I used the connector off a scrap regulator.

 

[normspanners]

for water drain you only need a tiny hole anyway, so upside down with an isolation tee and half length stand pipe for me is the easiest, we used 2 x 47's at 18 bar for the central heating pump on the boat it worked fine.

 

[Kent]

Any scientific proof of this or is it just internet gossip, I'd be interested in seeing the paper?

No a guy lost his face about 18 months ago on some road works. Old fuel tank had been cleaned but then stood. Horrific accident.
I have said this before but I have seen a wall taken down first hand it was a miracle nobody got seriously hurt
To recommend a young lad crack on with this is insane. Besides anything else you don't own these things they belong to the gas company.
I have been there before with folks saying this that and the other is OK. Often enough it isn't and you can't always go back and make things OK.

 

[Kent]

Because I can get free propane tanks (Gypsies aren't all bad) and people like Bill and BS who's opinions I'd trust say it's fine. That's not to say I don't trust your opinion (Quite the opposite actually) but there's more of them and they said it first.

EDIT: That reads more argumentative than I intended, hopefully it comes across more of a discussion than an argument.

Its OK it won't be me feeling guilty or worse if you join the rank of those who copped for the possible outcome that does happen sometimes

 

[normspanners]

That reads more argumentative than I intended, hopefully it comes across more of a discussion than an argument.

Did you pay for a half hour argument or a five minute one ? because some of this is contradiction, or is that a discussion ?------ ding thanks your 5 mins are up.

I might just doing it in my spare time.

 

[normspanners]

I'll probably put a bigger one on the side for a less restricted output too.

3/4 bsp has about 3/4 hole,
and a 1/4 hole requires a 100 cfm compressor to keep up at about 100psi , 3/4" is 10 x the size of 1/4" so that equates to about 1000cfm , so how much air do you want to pass !
you will need a big old compressor to be restricted, or maybe 5 or 8 road compressors all pumping into one tank to give you an idea ,

 

[Parm]

I am being "deadly" serious BTW. The propane can even contaminate the metal

Yes very dangerous, but don’t understand how the propane contaminates the metal ??

Be interested to understand how this happens

I’ve made quite a few BBQs out of cylinders, no issues to date

 

[Bsmith]

I am being "deadly" serious BTW. The propane can even contaminate the metal

Propane gas is actually almost odourless so gas companies add a pungent substance which gives propane/bottles the distinct smell. This substance does penetrate the steel and will hang around the bottle for long enough but is harmless as far as welding goes, IF THE BOTTLE HAS BEEN PROPERLY DE-GASSED. I always fill the bottles with water and let them stand full for a few days before cutting or welding.

 

[Burdekin]

Also propane is heavier than air. They are normally pressure tested to 24 bar, my compressor is 8bar. If you tig in steel bosses it will have to be very poorly welded to fail, the likely failure is a pin hole leak. If you are a competent welder you won't have an issue if just using the bottle for 8 to 10bar. The propane was higher pressure and flamable as opposed to lower pressure air.

I have a boss welded to the bottom for a drain pipe. If you search propane and Burdekin you will see my thread and pics.

 

[Bill Edwards]

Washing up liquid removes the lingering smell, hence my instructions.

It would be quite difficult to make a dangerous weld for a fitting. The slightest hole will cause air to leak, which means that provided it’s airtight it’s joined right round.
I think you would struggle to make an airtight joint with zero penetration.

Even most hobby migs would suffice, the metal involved is actually not very thick.

 

[8ob]

. I always fill the bottles with water and let them stand full for a few days before cutting or welding.

Thats what I have been doing with the bottles I mean air tanks that I have modified

Bob

 

[Kayos]

I’ve picked up a load of old fittings so will be adding a medium sized receiver to my setup

 

[Burdekin]

Washing up liquid removes the lingering smell, hence my instructions.

It would be quite difficult to make a dangerous weld for a fitting. The slightest hole will cause air to leak, which means that provided it’s airtight it’s joined right round.
I think you would struggle to make an airtight joint with zero penetration.

Even most hobby migs would suffice, the metal involved is actually not very thick.

About 3mm if I remember correctly. At 8bar it would pretty much need to be a hole in the tank before any chance of leaking. The weakest part is the long seam weld so if laying horizontally don't have the seam along the bottom for the weld to corrode from the water drop out.

 

[normspanners]

About 3mm if I remember correctly.

YEP 3mm makes you laugh RE the old receivers, 3/8 boiler plate and 160 psi working pressure and them failing insurance certs for a BIT of pitting !! even half rusted through and they were still thicker, in reality there is not much chance of them going bang the amount of truck ones that pit through , all that happens is they just end up leaking.

cant see it being 1/2 mm !!

 

[MattF]

cant see it being 1/2 mm !!

If it exploded, where was the damaged, ripped section, on the tank?