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LPG bottle gas flow problems .......

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Category: Saltwater Fishing
Forum Name: The Captain Morgan Briny Bar
Forum Description: The place for general chat on saltwater fishing!
URL: https://www.fishing.net.nz/forum/forum_posts.asp?TID=133876
Printed Date: 19 Sep 2020 at 12:56am


Topic: LPG bottle gas flow problems .......
Posted By: bazza
Subject: LPG bottle gas flow problems .......
Date Posted: 08 Jul 2020 at 8:26pm
We have four LPG bottles bottles one for house cooktop, second for the outdoor BBQ, the third for the motorhome & the fourth as a spare.
Have always favoured having these cylinders refilled over swap a bottle
for no particular reason other than could refill or top up at anytime a part filled bottle without having to pay full price for a "swappa bottle" & never had any probs.
 
However refill stations for some time have been increasingly hard to find, consequently for the sake of convenience began using "swappa bottles" & the problems began.
 
At times when the cylinder weight indicated plenty of gas remained the burners would not light which was a real P off with food all ready to go on the bbq ... sometimes bashing the regulator with a lump of wood & using a long match directly to the burners rather than using the igniter would restore normal service but was a real PITA all the same.
 
Likewise when leaving on a recent M/home trip the cylinder felt quite heavy so naturally assumed would be more than adequate however later on decided to give some of the utilities a dummy run only to find none of them would ignite !
 
Had the cylinder refilled & problems gone however it was established it had been 1/3 full so should have worked regardless.
 
About that time the Motor Caravan Ass magazine arrived & there was a technical article on the increasing prevalence of such experiences & the reasons for it. The technical aspects were a bit involved for a layman but they did make the point that problems were far more likely to occur with "swappa bottles" due to the comparative purity of product as "swappas" are not emptied before refilling therefore can have a huge % build up of butane which causes problems particularly in colder weather.
 
From hereon I am going to refill empty cylinders rather than swap &
would advise others that want to avoid like problems to do likewise.


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Am enjoying retirement so much that would not go back to work even if they paid me !



Replies:
Posted By: Catchelot
Date Posted: 08 Jul 2020 at 8:52pm
Originally posted by bazza bazza wrote:

About that time the Motor Caravan Ass magazine arrived 

I am not sure about the gas issues, but when I read above with your Caravan Ass magazines, I wonder whether your campervan and caravan parks are actually a rouge for your sunseeker, nudist, swap a blue hair as it were... bit of a worry you are Bazza!LOL


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"The sea, once it casts its spell, holds one in its net of wonder forever." - Jacques Cousteau


Posted By: bazza
Date Posted: 08 Jul 2020 at 9:02pm
Originally posted by Catchelot Catchelot wrote:

Originally posted by bazza bazza wrote:

About that time the Motor Caravan Ass magazine arrived 

I am not sure about the gas issues, but when I read above with your Caravan Ass magazines, I wonder whether your campervan and caravan parks are actually a rouge for your sunseeker, nudist, swap a blue hair as it were... bit of a worry you are Bazza!LOL
 
That I should be so lucky .... but dreams are free I guess.
 
However I think you misunderstood the intended meaning of the word "layman" on this occasion.
 
 
Re being a sunseeker .... just ask yourself what an exercise in futility that would be given the weather of late ... even no doubt in the so called winterless norf.


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Am enjoying retirement so much that would not go back to work even if they paid me !


Posted By: krow
Date Posted: 08 Jul 2020 at 9:37pm
So true. LPG is a mix of (mostly) 2 gases Butane and Propane. If you just use a small appliance with small jet and it's warmish you can empty a bottle. If not the butane may remain as a liquid and not enough gas will be delivered to the appliance. Multiple refills with high use appliances like heaters and you have a bottle that has mostly butane as above. Tip though if you shake the bottle some will turn to gas and you can keep going. just have to give it a shake regularly. 
I too always get my own bottles filled. 
I sometimes get called out to a "gas leak" because some smart individual has decided to empty their butane into the atmosphere. 


Posted By: Big -Dave
Date Posted: 08 Jul 2020 at 9:54pm
I have been known to sit a near empty bottle in a large tub of warm water to assist the bottle in giving up its gas...
They don't like the cold...
And I have heard of gas going stale..or something..

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you can't fix an idiot with duct tape, but it does muffle them for a while...


Posted By: pjc
Date Posted: 09 Jul 2020 at 4:05am
Thank "Bazza"We have been refilling when bottle felt 1/2 full and then find the bbq wont ignite unless using match.Think I will run bottle out from now on.If I fill up at the gas testing station in Mahia Rd Manurewano problem but problem started when filling at petrol station,surely their gas would be a high turn over so stale gas in their tank shouldnt be a problem??

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She said you're deaf.No I have selective hearing.And thats when it started.


Posted By: Dagwood
Date Posted: 09 Jul 2020 at 6:20am
Originally posted by pjc pjc wrote:

but problem started when filling at petrol station,surely their gas would be a high turn over so stale gas in their tank shouldnt be a problem??

The knowledge level and attitude of the person filling it would probably be the influencing factor here I would think! :-)


Posted By: Dagwood
Date Posted: 09 Jul 2020 at 6:21am
Slight thread drift! - 
We've just bought a house with a couple of 45kg for the hot water and hob. Does anyone own their own cylinders and get these filled or does everyone just use a delivery company?

It's been a devil of a job trying to compare rates between companies..


Posted By: bazza
Date Posted: 09 Jul 2020 at 8:05am
Originally posted by pjc pjc wrote:

Thank "Bazza"We have been refilling when bottle felt 1/2 full and then find the bbq wont ignite unless using match.Think I will run bottle out from now on.If I fill up at the gas testing station in Mahia Rd Manurewano problem but problem started when filling at petrol station,surely their gas would be a high turn over so stale gas in their tank shouldnt be a problem??
 
According to the article Paul your problem (mine too) has occurred due to an excess of butane in your gas mix which causes the gas to flow at a faster rate than normal signalling a hose could be cut or loose thereby triggering the cut off mechanism.
 
The article lists methods that might temporarily remedy the problem but does emphasise it is preferable to refill from empty rather than risk likely problems from swappa bottles.
 
This forum will not allow me to post pics or images so unable to scan & post the article unless I e-mail it to someone to post on my behalf.
 
Alternatively if I get time today could copy/type the pertinent paragraghs then post to the thread as imo is something all LPG users should be aware of but we are NOT told.
  


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Am enjoying retirement so much that would not go back to work even if they paid me !


Posted By: reel crayze
Date Posted: 09 Jul 2020 at 8:26am
We have had the same thing when we were away in the caravan.. a very weak flame when the bottle felt like it was was 1/3 full... mind you it may of had something to do with the temp... it was minus 5 or 6 Shocked


Posted By: bazza
Date Posted: 09 Jul 2020 at 9:16am
Originally posted by reel crayze reel crayze wrote:

We have had the same thing when we were away in the caravan.. a very weak flame when the bottle felt like it was was 1/3 full... mind you it may of had something to do with the temp... it was minus 5 or 6 Shocked
 
Yeah and at the risk of appearing pessimistic cannot help but wonder if that is the reason for the problem as it is in swappas interest to swap a 1/3 full bottle and charge for a full one ... whereas if refilling simply pay for the gas supplied to fill. Plus it would seem that doing so not only dramatically increases the profit margin but also the extent of
excess butane in the mix.


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Am enjoying retirement so much that would not go back to work even if they paid me !


Posted By: bazza
Date Posted: 09 Jul 2020 at 9:57am
OK here goes ... copied from the latest NZMCA magazine :-
 
Of late many members have been having problems with LPG bottles.
 
One of the problems occurs when having replaced the cylinder there is no gas flowing from the cylinder which is caused by an initial excess flow triggering the built in QCC safety valve. The purpose of this valve is to shut off gas flow should a hose or suchlike being damaged or cut.
However this valve can also be triggered by connecting the regulator on too quickly or having another appliance such as freezer, hot water,
or heating being switched on aggravating the problem. This can sometimes be rectified by turning off everything removing regulator and re installing then turning on the cylinder tap all very gradual.
 
Problems most likely to occur in cold weather when gas can be predominantly butane a combination likely to reduce gas pressure resulting in increased flow which triggers the safety shutoff valve.
 
This is one of the good reasons NOT to use swappa bottles instead have them refilled at a reliable outlet that offers control of the grade of gas being supplied & as a general rule you should ensure cylinders are empty as possible thus reducing the ratio of butane gas in the cylinder.
 
By comparison swappa bottles are not emptied before filling so can have huge percentages of butane which is a problem gas, particularly in cold weather.


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Am enjoying retirement so much that would not go back to work even if they paid me !


Posted By: Steps
Date Posted: 09 Jul 2020 at 10:23am
Winter? Frosty morning?
 Or a tank that is too small for the amount of lpg the appliance draws?
 LPG is pressure is directly related to the ambient temp.
 Hence Dave's  put in a warm bucket water type of soln.

If the tank is too small, say a 2.5kg tank on a bench heater, it will start of well, then slowly coool down as if the tank is near MT.
 Reason is as you draw off the lpg , the volume in the tank increases, and the temp of the tank/liquid inside decreases ( as it a frosty morning) and the pressure decreases.

 The other issue maybe the type of tank fitting.
Most these days have a fitting that is 'spring loaded'. As you screw the regulator hose in, gets to the 'O' ring sealing, pushes the spring loaded valve open to allow gas flow.

Do not over tighten brass fittings
 If these have been over tightened, the threads and seal surfaces get distorted and can stop the spring loaded valve from opening.

And last is the regulator.. is it the correct regulator for the appliance .. check the regular specs stamped on it match the requirement specs on the appliance.

Then lets say up gave a regulator to small, a frosty morning, and fittings that have been abused... or any 2 of these, let alone 3... you will have issues for sure.

As to hard lighting and do have gas... the mixture of gas to air at the point of ignition combines with ambient temp are all critical to ignition.
On a frosty morning it maybe harder to ignite, may need bigger flame to momentary 'heat' the air at point of ign... and a breeze moving air will change the air to fuel ratio.

Side note here.. LPG has a far narrower air to fuel ratio % to ignite in than say petrol.. outside this ratio it will not ignite at all.

I spent over 40yrs working with automotive lpg and 5yrs lpg as a propellant.


Posted By: pjc
Date Posted: 09 Jul 2020 at 11:12am
http://www.stuff.co.nz/national/2672638/Rubbish-gas-leaves-users-cold" rel="nofollow - http://www.stuff.co.nz/national/2672638/Rubbish-gas-leaves-users-cold

The difference between propane and butane is that propane will not liquefy until temperatures get down to -40 degrees celsius, but butane turns into liquid at zero degrees. When it is liquid, it sinks to the bottom and becomes harder to use.
A Wellington LPG hardware supplier, who did not want to be named, said when the mix got close to 50 per cent butane it was rubbish. "In the colder months you won't get it out of the bottle."
Separating butane from propane would add extra costs in production, freight and storage, as well as creating a surplus of butane that could go to waste, Mr Gilbert said.


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She said you're deaf.No I have selective hearing.And thats when it started.


Posted By: SaltyC
Date Posted: 09 Jul 2020 at 11:24am
Propane has a specific gravity of .495 whilst butane is .601 (both as liquid) so the butane naturally ends up below the propane if stored for any length of time.

Always give the bottle a good shake if it hasn't been used for a while to help to recombine them so the butane is not left in the bottom when most of the propane has been used.

Also butane needs a different air to gas ratio (higher) than propane so you should also notice that the flame is more orange/yellow than blue when there is more butane than propane being burnt as it won't be combusted completely when the burners are set properly for LPG. This can also mean more carbon monoxide is produced as the gas is not fully combusted.


Posted By: Steps
Date Posted: 09 Jul 2020 at 11:42am
Upo to a few yrs or s/, decade or so there was no std in NZ for LPG butane/ iso butane/ propane mix.
 Caused all sorts of issues espec for gas used for automotive. On fill used quick and no power, next the vehicle would go like hell and tank last for ever.

And the bbq / appliances, no heat to cook a steak, next fill would burn it.
 For the last few yrs the BTU /kg....octane....gas mix has been standardised
 And no, they do not separate.. they are full dissoluble..to separate would take very very long impractical lengths of time.. and just carry a container they will mix.
 We/I used to blend gases and assess product separation in pressurised clear glass aerosols in R&D lab work.

If it was an issue it would be common in low use 45kg bottles...We have 2.. each takes a good 2 to 3 months to MT which means the 2nd bottle can be stood , very still for long period, and still still for another 4 to 6 months total...
 Even thu useing, it is vapour pressure off the surface of the liquid gas inside...If did separate even slightly would mean would only be using propane, and get to the butane/ iso butane cooking would be near impossible.


Posted By: krow
Date Posted: 09 Jul 2020 at 6:13pm
Originally posted by Dagwood Dagwood wrote:

Slight thread drift! - 
We've just bought a house with a couple of 45kg for the hot water and hob. Does anyone own their own cylinders and get these filled or does everyone just use a delivery company?

It's been a devil of a job trying to compare rates between companies..
New law a couple of years ago means the filling company cannot fill your bottle unless you can transport it upright. 


Posted By: Dagwood
Date Posted: 09 Jul 2020 at 6:54pm
[/QUOTE] New law a couple of years ago means the filling company cannot fill your bottle unless you can transport it upright. [/QUOTE]

Have a trailer with a cage.. piece of cake to lash upright... Will be having a conversation with the local refilling bloke and seeing what he says..


Posted By: Clutch
Date Posted: 09 Jul 2020 at 7:17pm
I'd love to hear the answer Dagwood.


Posted By: wayno
Date Posted: 09 Jul 2020 at 7:42pm
My 45kg bottles are replaced via my supplier only when I request a replacement. I often find the changeover valve has operated during cooler months when the sun doesn't hit the tanks there is product left in the cylinder. My solution is to wait until spring/summer to get the last out of the tank. Helps that I live alone and don't have too many house guests over winter. 1 x 45kg lpg tank usually lasts between 6-8 months.

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To be old and wise you must first be young and stupid.


Posted By: Steps
Date Posted: 10 Jul 2020 at 10:33am
My 45kg bottles are replaced via my supplier only when I request a replacement. I often find the changeover valve has operated during cooler months when the sun doesn't hit the tanks there is product left in the cylinder. My solution is to wait until spring/summer to get the last out of the tank. Helps that I live alone and don't have too many house guests over winter. 1 x 45kg lpg tank usually lasts between 6-8 months.

We found a similar issue..Our tanks are on the sth side of the house ,always fully shaded.
After a bit of messing around, found that only turning the tank in use. ( in effect Turn off the auto turn to full tank valve). And turn on the full tank when hot water doesnt heat or the hob doesnt light.. bit of a nuisance if in the shower, but usually happens other times. And if in the shower only maybe once a yr..
Now each tank gets fully MT and at least an extra 1 or 2 weeks out of a tank.

It you ask your suppliers, or the truck driver, they will put a tag on your installation that says the tanks must be turned off as above.

From memory the regulations on transporting tanks 25kg and above must be carried vertically in a cage and may need approval/ certification to do so.
Exception is automotive tanks that require certified anchoring and ventilation.
 
We looked into rent or owning lpg tanks.. bottom line even thu the min bottle renal is 2 bottles, and seems expensive, the inconvenience of disconnecting, loading to take for refill, the cost of the refill gas, then home, manhandle into place is just not worth the time the money or effort.

Side note here on cost lpg.
 If you turn over your tanks quick, your cost of lpg per tank is significantly lower than if turn them over  a longer time.
 The cost of your lpg is the cost of the gas inside plus the cost of the time you rent the tank ...more time your total cost of a tank goes up.
 Therefore it maybe more prudent to swap a bottle 2x 9kg tanks every month Wink

Another side note: putting in solar panals and have A rinnai on demand hot water. with solar panels the aim is to use and not return to the grid , as much power as possible. A battery will cost another 17K
 You can store energy (what a battery does) by putting in say a 100 or 180L hot water cylinder ( a way to store energy) with a 2000w element. And excess kw can go to the HWC before going to the grid. If temp is below 65 deg it means the rinni unit gets pre heated water and uses less lpg.
 Which then means (above) even a 4 person household on lpg hot water and hob can easy go to 9kg bottles.

Anyone got a good 2nd hand 180L hwc they dont want?


Posted By: Dagwood
Date Posted: 10 Jul 2020 at 11:48am
Originally posted by Steps Steps wrote:

 Therefore it maybe more prudent to swap a bottle 2x 9kg tanks every month Wink  

Will a 9kg bottle be capable of supplying the flow needed for a califont and hob?


Posted By: Big -Dave
Date Posted: 10 Jul 2020 at 2:26pm
I used a 9kg bottle when my 45 ran out.
Ran the Califont fine.
It takes me over a year to use a 45kg bottle.

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you can't fix an idiot with duct tape, but it does muffle them for a while...


Posted By: Steps
Date Posted: 10 Jul 2020 at 4:00pm
Will a 9kg bottle be capable of supplying the flow needed for a califont and hob?

I assume you mean the amount of lpg used, in a period of time, drops the internal temp of the 9kg gas bottle, which results in a dramatic pressure to the supply?

I brought this up with a concern with family a while back...
They had asked around others . and no issues.

 As per Dave
My daughter husband and 4 boys , hob and califont is fine unless once in a while after sat morning sports or camping holiday  the showers, and stoves are going hard out.. extreme loading and length time.

 Son wife and 2 children no issues.


Posted By: Catchelot
Date Posted: 11 Jul 2020 at 9:02am
Looks like Bazza adjusted the gas jet a wee bit much! LOL




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"The sea, once it casts its spell, holds one in its net of wonder forever." - Jacques Cousteau


Posted By: bazza
Date Posted: 11 Jul 2020 at 11:33am
Originally posted by Catchelot Catchelot wrote:

Looks like Bazza adjusted the gas jet a wee bit much! LOL
Not guilty .... am surprised Al that you don't remember having farted at your family bbq !



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Am enjoying retirement so much that would not go back to work even if they paid me !


Posted By: Dept Of Fishing
Date Posted: 23 Jul 2020 at 9:35am
Hi everyone, new member to the forums here.
I use a small screw on camping stove at times and when I recently bought a new gas canister for itI noticed that it had a different mix than the previous one I had.  One is 25% propane and 75% butane, the other is 20% propane and 80% butane.  Is there any advantage in a higher butane %age?  I got one from Bunnings and I think the other one was from Mitre10.


Posted By: Steps
Date Posted: 23 Jul 2020 at 9:43am
The more propane the hotter the flame...or more BTU (energy) per kg.



Posted By: Dept Of Fishing
Date Posted: 23 Jul 2020 at 10:46am
Thanks for that.  I will have to look at this next time I need to get another canister (an compare the price too)



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