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SimonT

Safefill first fill

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When you buy a new Safefill gas bottle you are told to only put a reduced amount of gas in, the first time you fill it.  Can anyone tell me the technical reason for this and also when is it then safe to fill it up normally.  With my first bottle I used most of the gas before filling it again but I have another bottle and would like to top it up to full without using all the gas first. 

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5 minutes ago, SimonT said:

When you buy a new Safefill gas bottle you are told to only put a reduced amount of gas in, the first time you fill it.  Can anyone tell me the technical reason for this and also when is it then safe to fill it up normally.  With my first bottle I used most of the gas before filling it again but I have another bottle and would like to top it up to full without using all the gas first. 

 

Maybe I have this wrong but I believe there is no way to expunge the air in a new bottle which is trapped and compressible. LPG when compressed turns to back to liquid but air cannot. When a small amount of LPG is added and the bottle is used, the air is removed going out through the appliance.

This logically applies to Alugas, Gasit and Gaslow bottles as well although I only heard the requirement from Safefill so I'm not sure how important following the instruction is.

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I would think that as LPG in gas form is heavier than air, any air trapped in the bottle would be on top of everything else and could be quickly blown out when the bottle is first used. If so, it would be better to first use it on either the gas hob or a BBQ where you can see the flame when it lights.

Not too much different from when you first light a BBQ after changing a cylinder, all the air has to be blown through before it lights.

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Sorry if I appear a bit dim but how does LPG compare to Propane or Butane for cold weather use & will it work ok on caravan appliances without modifications to the burners ?.I assume it will but you can’t just trust assumptions when it comes to safety , thanks ,   Steve.

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2 minutes ago, stevew1 said:

Sorry if I appear a bit dim but how does LPG compare to Propane or Butane for cold weather use & will it work ok on caravan appliances without modifications to the burners ?.I assume it will but you can’t just trust assumptions when it comes to safety , thanks ,   Steve.

LPG is propane!

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24 minutes ago, Stevan said:

LPG is propane!

 

Oh , ok thanks for that , it will work everywhere that my present cylinders will then  , at a lot less cost after initial purchase .

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I emailed Safefill and this is their reply, "Hello Martin,It's very important as air in the cylinder can affect the safe function of the opd, all OPD's work on pressure differential, t hat's why its important you always follow the filling instructions and check the fill level after each fill. Pump delivery pressure at the pump should aways be set correctly, unfortunately we have no control on this so as per the instruction leaflet guide always check. I hope this helps Regards Neil"

 

OPD - overfill protection device

 

As an engineer, this makes no sense.  The OPD is a float valve!  I think the OPD is probably prone to freezing until the air and any moisture in the cylinder has been purged.

Edited by kelper

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1 hour ago, Stevan said:

LPG is propane!

LPG is not propane in Europe where  it is a propane/butane mix, mainly propane.

 

I was told by a fluke of nature the larger butane molecules although at a lower pressure for the same ambient temperature burn at a higher temperature and thus releases about the same as smaller propane molecules at a higher pressure so no re-jetting of appliances is required, just the appropriate regulator either 28 or 37 mbar. Caravan regulators are a 30 mbar compromise to allow use of both bottle types using the same regulator.

 

As an aside, some ready filled camping (Gaz?) cylinders have a propane/butane mix and in cold weather the propane gets used up first leaving you with a cylinder of butane gas that you struggle to get out without warming it up. Not very user friendly. Refineries have to get rid of the stuff somehow.

Edited by limecc
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My Alugas was filled to the brim the first time, it was done for me by the pump attendant, no.mention on blurb of not doing so. As said above the cut off valve is a float valve. I used to have an lpg car and that said nothing about not filling it right up, sounds odd.

I you decide to fill it up then as someone else mentioned probably run it on the BBQ before you fit it to the van.

I thought all these things were supposed to have a safety valve so it the pressure got to high it would open anyway?

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7 minutes ago, Jiffy176 said:

 I used to have an lpg car and that said nothing about not filling it right up, sounds odd.

 

All LPG cars should have a built in overfill protection device to automatically shut off at 80% fill.

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By fill to the brim I mean until the OPD cuts in not part filling as the safefill suggests.

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Thanks for all the replies. I thought it was to do with releasing the pressurised air. So, if I just use the bottle for a bit any air should get pushed out and then I can fill it to 80% as usual.

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I forgot this instruction when I filled ours for the first time, no adverse effects, but on the next fill the level was a little lower.

 

Mark

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I bought two bottles last year. I find it almost impossible in normal daylight to see how far they are filled to. The first time I filled both they filled completely.

I phoned Safefill and was told "Don't worry they should be fine"

 

They were.

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1 hour ago, Jimd said:

I bought two bottles last year. I find it almost impossible in normal daylight to see how far they are filled to. The first time I filled both they filled completely.

I phoned Safefill and was told "Don't worry they should be fine"

 

They were.

 

Same here - full first time BUT it's quite easy to see level by gently shaking bottle and looking at the openings at an angle rather than straight on.  One gentle shake will disturb the liquid for quite some time.

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You should not fill a SafeFill until it cuts off!  The OPD is there as a last resort.  It's like stopping lift doors closing by sticking your arm in the way.  The door safety edges do fail.  

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25 minutes ago, kelper said:

You should not fill a SafeFill until it cuts off!  The OPD is there as a last resort.  It's like stopping lift doors closing by sticking your arm in the way.  The door safety edges do fail.  

 

There really is no other way to do it!

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2 hours ago, kelper said:

You should not fill a SafeFill until it cuts off! The OPD is there as a last resort. 

Drama queen. Not to be complacent but did anyone ever hear of a failed cutoff valve? As a long time Autogas user if there was a particularly powerful pump filling a big old tank you could sometimes trickle a little extra in after you hear the definite stop but the flow is so slow you give up due to impatience. Ambient temperature has a big effect on fill volumes and I found a wide variety of (obvious) pump miscalibrations because nobody ever checks them like for petrol.

In any case the overpressure safety vent is the last resort I believe. 

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On 17/09/2019 at 10:27, kelper said:

As an engineer, this makes no sense.  The OPD is a float valve!  I think the OPD is probably prone to freezing until the air and any moisture in the cylinder has been purged.

As a former engineer it makes plenty of sense. Think of the air as a compressible balloon in the top of the tank, the level cannot rise as easily because of greater resistance (it also being compressible with a different spring rate), thus the float is allowing slightly more liquid into the cylinder before it finally closes the valve.

Edited by limecc
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On 17/09/2019 at 09:50, Stevan said:
On 17/09/2019 at 09:47, stevew1 said:

Sorry if I appear a bit dim but how does LPG compare to Propane or Butane for cold weather use

 

LPG is propane!

 

LPG = Liquid Petroleum Gas (LPG).  

 

Propane, Butane and Autogas are all LPG.

 

Quote

LPG is used as a fuel in a range of applications including in heating and cooking appliances, industrial applications, in vehicles and as a propellant and refrigerant.

 

LPG can be obtained primarily as propane, butane or a mixture of the two.

http://www.hse.gov.uk/gas/lpg/index.htm

 

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