gas filler valves

[Ian AbbottParticipant @ianabbott31222]

Acetylene is disolved in a carrier, the name of which for the life of me has left my head, to stabilise it, as it is unstable and will explode spontaniously at anything above about 15 ponds per square inch.  If the tank has been on its side, the carrier will be pulled into the valve.  Or words to that effect, It’s been a long time since I had to teach it.

 

Propane.  In frigid North America, butane is almost unheard of, it just don’t gas at low temperatures.  We heated our house and cooked on propane, kept in a thousand gallon tank beside the drive, when it gets too cold, everyone puts a heat lamp over the regulator to keep it working.  All trailers (caravans) and campers use propane.  The critical bit is in where the intake spout is in the tank.  On its side it will pick up liquid gas, with predictable results.  If you’ve ever tipped a propane torch too far forward, it will do flary kinda stuff, same thing.  

 

Ian 

[Anonymous]

As I understand it the acetylene is dissolved in acetone, which is itself held in a porous material. The porous material used to be kapok. This explains why acetylene cylinders are disproportionately heavy. Nice stuff acetylene, that’s what you get from a triple carbon bond!

 

Regards,

 

Andrew

[Sub MandrelParticipant @submandrel]

This is all interesting stuff. For the record, though, LPG for cars is pure propane as far as I am aware. Ian – you will be interested that the gas pickup for LPG cars is low down and the liquid gas comes to a vaporising unit that is heated by the engine coolant. I have cleaned and fitted new gaskets and diaphragms to the  vapouriser on my car and my wife’s)  as the can gum up (LPG appears to have a lot of stinky yellow goo dissolved in it). The units have a two-stage regulator, a miniture version of one would be a nice project for a gas-fired model.

 

This approach means that, even in the recent -12 degrees I haven’t had any problems – [petrol start and runs for about 2 minutes before switching over. No problems with fuel shortage, although my wife’s car switches back to petrol after a mile in cold weather, I suspect hers has a different cooling system that sends a slug of cold wather through the vapouriser when the thermostat switches in the first time.

 

Neil

[Anonymous]

Hi Nick,

 

I’ve read the regulations, and as far as I can see private individuals using the equipment for pleasure purposes are exempt. So, for the glider, at least, I don’t need to worry. At least until the bureaucrats realise that glider pilots are fitting, and using, high pressure oxygen equipment without a license or EU regulation in sight. My system runs at about 2000psi and it normally sits just by my right thigh. It is supposed to be tested every five years, and I make damn sure it is tested!

 

Regards,

 

Andrew

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I know this is getting away from the OP, but I will just add a little more.

 

   Andrew,

                   I’m not sure if kapok is still used, but you are spot on. Without going into it with to much detail, the kapok holds the acetone and the acetone holds the acetylene.

The chemical formula; C2 H2 makes it the hottest and most efficient fuel gas and I beleive the most explosive with the flammability limits between 2% and 82% in air. Yes nice stuff but doesn’t like silver, mercury or copper. It will form acetylides with them, which are impact explosives, i.e. just the slightest knock can make them explode.

 

   Ian,

          yes it does become very unstable above 15psi, but the acetone will be drawn off if used when laying down or if not allowed to stand upright for the specified period after being layed down. Drawing off acetone will reduce the efficiency of the flame, but more over will reduce the ability to hold the acetylene in a stable state inside the cylinder.

 

   Neil,

            the stinky yellow goo, is probaly residue from the smell they put in to it at the refinery, as LPG is naturally oderless.

 

Regards Nick.

Edited By Nicholas Farr on 30/12/2010 20:02:03

Edited By Nicholas Farr on 30/12/2010 20:09:20

[Richard ParsonsParticipant @richardparsons61721]

 

Andrew I think you will find that the important words are ‘Portable Cylinders’. Your ‘gin bottle in your glider is not portable; it is part of the glider its self. In fact as I remember it aircraft the high pressure side of oxygen systems integral to the point of the pressure regulator.  I think there are no cut off valve on the bottles. One would feel a little foolish if you suddenly needed oxygen and could not get it because you had not switched the system on when you were on the ground.

Unlike most of the rules made by ‘Elfin Safety’ the one about portable bottles is actually very sound. If you have the regulators etc rigged and they got broken off but the cyinder valve had not been closed  “Wow”! Oxygen is at 2000 psi! 

Acetylene is nasty stuff if you do not follow the rules. I queried BOC over the use of copper manifolds when were using multiple bottles of DA (Dissolved Acetylene) manifold together when using oxygen lances to cut concrete block houses to bits.  they said it was ok as the pipes were dry.  Although the whole system was at full cylinder pressure (200 psi).  

Copper Acetylide goes bang with a sharp rap. Silver Acetylide will go ‘snap crackle and pop’ as it dries out or if you look at it cross eyed

Edited By Richard Parsons on 31/12/2010 11:11:42

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Richard, copper manifolds with acetylene? I’ve only ever had training with portable equipment so I can’t question this, but copper tube in a split or cut hose was very much frouned apon, and was regarded as being very un-elfin safety. This was at BOC seminars. Steel was regarded as an temporey OK in acetylene, but not in oxygen, where copper could be used.

 

    Andrew, yes the regs I was refering to were for “portable” classed equipment.

 

Regards Nick.

[Richard ParsonsParticipant @richardparsons61721]

 

Long years ago the authorities decided to remove a wartime blockhouse. Pneumatic drills just bounced on the concrete. The R.Es said they could not be blown it was too near houses. 

Someone suggested ‘Oxygen lances’. These are long tubes heated white hot at one end and through which you pass Oxygen.. BOC did the job with several 100s of yards of 1 ½ inch pipe Dozen of bottles of Oxygen all manifold with 1 regulator. There was a similar arrangement for the DA which was used to heat up the tubes. The fun started it made Guy ffawlks night seen tame. About every 5 minutes a new pipe was used. About every ½ hour another load of Oxygen and DA was delivered.

The manifolds were all thick copper pipe and were made and sold by BOC for that job

After about ½ a day the block house was reduced to a series of very hot man lift able blocks.

Job done but the blockhouse used to make a good camp for us kids and the local ‘peeler’ knew were we all were.

 

[KWILParticipant @kwil]

Thermic lances were easily made from 1/2″ barrel, filled with as many 1/8 rods as you could force in. Heat business end with Oxy A and when glowing hot turn on the Oxygen supply. Point at concrete and push in to hole as it forms. molten metal brings out all the dross, amazingly efficient. Other uses of course.

[Ian AbbottParticipant @ianabbott31222]

Drove a Chevy pickup for a few years with a V8 on propane in Northern Alberta and down to the Salt Spring Island off Vancouver.   It had a fifty gallon tank taking up a chunk of the back and started every time, even down to minus forty if the block heater was left on.  There was no liquid fuel backup, so it had to.

 

Traveling  on the coastal ferries was no problem with that lot sloshing around, but one day I turned up at the Vancouver terminal with the oxy-acetylene and MIG with the argon bottle in the open on the back.  It was as if I were carrying a tub of nitro-glycerine, I had to sign waivers and declarations, and they had no idea what argon was, so they classified it as an explosive!

 

On the ferry, to Victoria, the truck was isolated with a two vehicle space and warning cones.

 

When I turned around to get on the smaller ferry to Salt Spring, I pulled a tarp over everything and just drove on…… 

 

Ian 

[Nicholas FarrParticipant @nicholasfarr14254]

Hi all, instead of hijacking this thread any further I have created a new thread on the subject of acetylene.

 

Regards Nick.   and A happy new year to all.

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