Gas problem

[Beehpee]

Hi all I have what seems to be some sort of blockage in the pipe that goes from gas bottle to bulk head regulator in caravan, disconnected pipe from regulator and when I turn on the gas bottle nothing comes through and there’s a slight click from the pipe as though something moves and blocks the pipe, I think it’s just a case of finding a caravan dealer tomorrow and buying a new pipe but some one might know of a fix.

BP

 

[Damian]

For the cost of a new pigtail it is not worth the risk of doing anything to them.
They must be viewed as a throwaway item. Trying to clear them with anything will compromise the material they are made of and potentially make it weaker and as such liable to burst under the pressure from the cylinder.

 

[Hutch]

Bp, out of interest is it a rubber coated one or a braided steel one, the rubber ones are lifed at 5 years I believe.

 

[ProfJohnL]

Hello Behpee.

From memory, Quite a number of years ago there was a gas bottle connection that incorporated an "excess flow" valve which was designed to stop the flow of gas if there was no back pressure in the pipe such as would occur if the pipe was severed in a collision. This would certainly give the symptom you describe. It would be automatically reset if the bottle was turned off and the connector released to drop the pressure between the gas bottle valve and the device.

I don't know if such connectors are still available today.

But if in doubt, change the pigtail.

 

[Beehpee]

Hi guys, thanks for the responses, I did think I’d just go and get a new one this morning as even though I’m not fond of health and safety rules and regs even I would rarely, if ever, mess about with anything gas related, Hutch it’s the rubber pigtail and I’d be surprised if it was less than 5 years old, not having gas for the evening last night wasn’t too inconvenient as got the Cadac and electric heating,

BP

 

[Beehpee]

Gas problem sorted, new pigtail, £11.99 and better because it’s got the thumb wheel so no messing with spanner, I learnt something as well, I thought the date on old pipe was manufactured date which was Feb 2015, if the guy at dealer is correct that was when it should have been changed, odd though new pipe has no date at all.

BP

 

[Damian]

The guy at the dealers is wrong.(but that seems to be norm for dealers)
The date on gas pipe and pigtails is the manufacture date and as long as the pipe has been stored correctly the time countdown for change is from the date the first gas is passed through it in the caravan.

 

[ProfJohnL]

The guy at the dealers is wrong.(but that seems to be norm for dealers)
The date on gas pipe and pigtails is the manufacture date and as long as the pipe has been stored correctly the time countdown for change is from the date the first gas is passed through it in the caravan.

The question is how does the customer know if it's been stored correctly?

The general advice is to replace flexible gas pipes that are more than 5 years old, and bearing in mind the comments above, and the uncertainty they introduce, the safest way is to be guided by the manufactured date printed on the pipe.

 

[Hutch]

I believe its only the rubber coated ones that are lifed at 5 years , the steel braided ones have a much longer life.

 

[Damian]

The working life of any pigtail or gas carrying pipe used in caravans and such like is determined from the day the pipe first starts carrying gas, and for low pressure it is 3 years maximum, for high pressure pigtails it is 5 years max and for stainless steel braided, which have a liner they are 25 years (as claimed by the makers).

However, any of them can become useless at any time within that timescale due to contamination from the gas, and low pressure hose should be changed every year at service time as they are the most unstable of the lot.
Do not think that braided pigtails are immune from problems, they are not !!

It is ridiculous to think that the time limit starts from the manufacture date as that would put every item partially time expired before it even left the factory.

As for storage, as long as the pipes are kept in a place that is not subject to wildly varying temperatures or where there is a high chemical environment around them, or in direct sunlight they are fine .
Most storage areas in workshops and shops selling such items are normally free from problems.

The date of fitment should be noted either on the service paperwork, or as I do, on a sticker in the gas locker with an advised change date also.

 

[Beehpee]

I’ve put a sticker in the gas locker myself so I will know when it needs changing, it’s the sort of thing that gets overlooked so I’ve made sure the sticker is visible every time I change the gas bottle, thanks for the clarification Damian.

 

[otherclive]

The working life of any pigtail or gas carrying pipe used in caravans and such like is determined from the day the pipe first starts carrying gas, and for low pressure it is 3 years maximum, for high pressure pigtails it is 5 years max and for stainless steel braided, which have a liner they are 25 years (as claimed by the makers).

However, any of them can become useless at any time within that timescale due to contamination from the gas, and low pressure hose should be changed every year at service time as they are the most unstable of the lot.
Do not think that braided pigtails are immune from problems, they are not !!

It is ridiculous to think that the time limit starts from the manufacture date as that would put every item partially time expired before it even left the factory.

As for storage, as long as the pipes are kept in a place that is not subject to wildly varying temperatures or where there is a high chemical environment around them, or in direct sunlight they are fine .
Most storage areas in workshops and shops selling such items are normally free from problems.

The date of fitment should be noted either on the service paperwork, or as I do, on a sticker in the gas locker with an advised change date also.

Tyres are lifed for caravans by their date of manufacture so do not adhere to your logic. I’ve been involved with safety critical systems carrying HP air at 3000psi, hydraulics, hydrogen and oxygen. All flexible pipes were lifed from date of manufacture. Wonder why caravan gas flexibles should be different.

 

[Damian]

Quote " Wonder why caravan gas flexibles should be different. "

Because the degradation is caused by the acidic nature of LPG and it is only when gas is passed through that this starts to happen.
LPG leeches out the plasticisers in the pipe, as well as leaving oily deposits in the pipe.

Quote " Tyres are lifed for caravans by their date of manufacture so do not adhere to your logic"

Tyres are exposed to the elements for all their life in use, sunlight , rain, salt on roads etc etc so cannot be compared to gas pipework which is inside an enclosure for its working life.