gas compression fittings

[MCFastybloke]

 

What's the alternative? Are soldered joints allowed? I understand they're not allowed on road vehicles because of vibrations. I realise you can't put drop-out holes on the bottom of boats.

compression joints are not allowed under floor or behind panels,anywhere a leak could be contained in a confined space creating a volume of trapped gas,as compression joints are regarded to be more leak prone due to mmovement.

[WotEver]

... compression joints are regarded to be more leak prone due to mmovement.

Not by the BSS they aren't. They're the only jointing method that is permitted.

[Chewbacka]

My mistake. It's not BSS which disallows it, it's PD54823.

 

It's still considered poor practice though, even if it's not a BSS fail.

It could be a BSS fail as the BSS question is - "Are all LPG pipe joints secure, in good condition and competently made?" my bold.

So an examiner if faced with a compression joint with PTFE spilling out could argue it was not competently made as PTFE is not normally required in a compression joint.

Not by the BSS they aren't. They're the only jointing method that is permitted.

Agreed, as the BSS states "All LPG pipe joints must be compression fittings on copper pipework or compression or screwed fittings on copper alloy or stainless steel pipework. "

 

[Mikexx]

Agreed, as the BSS states "All LPG pipe joints must be compression fittings on copper pipework or compression or screwed fittings on copper alloy or stainless steel pipework. "

 

 

I confess to being surprised at that. Domestic gas can use soldered joints and to my knowledge don't need to be accessible like compression fittings.

 

Mind, I have always been concerned that a leak test might pass due to flux blocking a gas pathway masking a poor solder joint.

[Chewbacka]

 

I confess to being surprised at that. Domestic gas can use soldered joints and to my knowledge don't need to be accessible like compression fittings.

 

Mind, I have always been concerned that a leak test might pass due to flux blocking a gas pathway masking a poor solder joint.

It is interesting as the BSS allows ony Compression fittings whereas the current ISO std - BS EN ISO 10239:2014 allows the use of 'hard soldered and brazed connections' with a melting point greater than 450c. So I could build a boat using hard soldered connections, CE mark it for sale, sell it and then it would fail the BSS.

Looks like the BSS office is failing to stay up to date with the regs.

[nicknorman]

It is interesting as the BSS allows ony Compression fittings whereas the current ISO std - BS EN ISO 10239:2014 allows the use of 'hard soldered and brazed connections' with a melting point greater than 450c. So I could build a boat using hard soldered connections, CE mark it for sale, sell it and then it would fail the BSS.

Looks like the BSS office is failing to stay up to date with the regs.

If you were the BSS man, how could you tell whether a soldered joint has a melting point >450C just by looking?

 

But anyway, as I mentioned earlier this is why the likes of MtB always ask what regulations a questioner wants to meet. The ISO is a pan European regulation, the BSS a British one and it is surely not the only area where U.K. requirements differ from European ones!

[bizzard]

Trouble is I doubt if many gas fitters know how to silver solder or braze. They might know how to braze a chicken though.

[Chewbacka]

If you were the BSS man, how could you tell whether a soldered joint has a melting point >450C just by looking?

 

But anyway, as I mentioned earlier this is why the likes of MtB always ask what regulations a questioner wants to meet. The ISO is a pan European regulation, the BSS a British one and it is surely not the only area where U.K. requirements differ from European ones!

Actually it is a British Standard - The ISO is into a British Standard, hence the name includes BS - BS EN ISO 10239:2014

 

As to the 450c requirement, the BSS bod can not check that, like he/she can not check that the copper pipe is soft and of the correct wall thickness and that you have used copper olives rather than Brass, so the BSS does not require the examiner to check what can not be checked. However if you used soft solder and someone is hurt as a result than you will be in serious trouble.

Edited January 13, 2017 by Chewbacka

[nicknorman]

Actually it is a British Standard - The ISO is into a British Standard, hence the name includes BS - BS EN ISO 10239:2014

I do find this all a bit confusing, but isn't the BS just a direct copy of the ISO? Therefore despite the label, it is an international regulation?

 

Edit: it's all explained here: http://standardsforum.com/what-is-the-difference-between-an-iso-en-iso-and-bs-en-iso-standard/

Edited January 13, 2017 by nicknorman

[Chewbacka]

I do find this all a bit confusing, but isn't the BS just a direct copy of the ISO? Therefore despite the label, it is an international regulation?

 

Edit: it's all explained here: http://standardsforum.com/what-is-the-difference-between-an-iso-en-iso-and-bs-en-iso-standard/

Welcome to the strange world of standards. There is an international standard and there is a British standard and the two happen to be the same.

What will be interesting, is that when we are no longer bound by EU directives we MIGHT end up where the ISO standard is updated, but we choose not to update the British Standard. Time will tell, but as organisations such as BS exist and survive on the basis of changing standards, then I guess that they will continue to keep updating.

[nicknorman]

I rather went off soft soldered gas joints after I had gas central heating installed by a reputable local heating company. The boiler was installed in an odd space under a mezzanine bathroom, effectively an outside "shed" with limited headroom and space. Anyway one day I went in there to get some stored junk and accidentally leant on the gas supply pipe, which promptly pulled out of a soldered joint and started pouring gas out as I looked at the open end of the pipe! Oops, quickly turned off the gas at the mains. There seemed to be plenty of solder but it was a dry joint or something.

There is an international standard and there is a British standard and the two happen to be the same.

 

"Happen"? But it's by design not by coincidence - the BS has to reflect the EN which normally is based on the ISO.

[stegra]

 

I confess to being surprised at that. Domestic gas can use soldered joints and to my knowledge don't need to be accessible like compression fittings.

 

Mind, I have always been concerned that a leak test might pass due to flux blocking a gas pathway masking a poor solder joint.

 

 

I confess to being surprised at that. Domestic gas can use soldered joints and to my knowledge don't need to be accessible like compression fittings.

 

Mind, I have always been concerned that a leak test might pass due to flux blocking a gas pathway masking a poor solder joint.

 

Natural gas (domestic) mixes freely with air so can be smelt if there is a leak; The smell is actually added for this purpose. LPG is heavier than air so can gather unnoticed. Drop-out holes are normally provided to allow LPG to escape but if you put them in a boat you won't need to worry about what the inspector thinks. I don't know how the regs vary for different craft but movement of the structure is probably the reason for prohibiting soft solders. Houses aren't supposed to move.

 

Pressure testing is normally carried out at 2 bar or more so any solder joint that isn't properly made should show up. Gas pressure, after the regulator, is a fraction of this.

[David Mack]

And boats are subject to a level of vibration you don't normally get in houses.

[bizzard]

Boat catches on fire, gas pipe soft solder melts, escaping gas adds to the inferno, big time.

[WotEver]

Boat catches on fire, gas pipe soft solder melts, escaping gas adds to the inferno, big time.

 

Have a greenie

[stegra]

I rather went off soft soldered gas joints after I had gas central heating installed by a reputable local heating company. The boiler was installed in an odd space under a mezzanine bathroom, effectively an outside "shed" with limited headroom and space. Anyway one day I went in there to get some stored junk and accidentally leant on the gas supply pipe, which promptly pulled out of a soldered joint and started pouring gas out as I looked at the open end of the pipe! Oops, quickly turned off the gas at the mains. There seemed to be plenty of solder but it was a dry joint or something.

 

"Happen"? But it's by design not by coincidence - the BS has to reflect the EN which normally is based on the ISO.

 

Yeah. Dry joints are quite alarming. I once stripped a domestic heating system and the majority of joints were dry; you could just pull them apart. As long as the pipe ends are properly cleaned using wire wool and some flux and the fittings aren't oxidised at all, they shouldn't happen.

[MtB]

 

 

Natural gas (domestic) mixes freely with air so can be smelt if there is a leak; The smell is actually added for this purpose. LPG is heavier than air so can gather unnoticed. Drop-out holes are normally provided to allow LPG to escape but if you put them in a boat you won't need to worry about what the inspector thinks. I don't know how the regs vary for different craft but movement of the structure is probably the reason for prohibiting soft solders. Houses aren't supposed to move.

 

Pressure testing is normally carried out at 2 bar or more so any solder joint that isn't properly made should show up. Gas pressure, after the regulator, is a fraction of this.

 

 

I need to take issue with you here. New LPG gas pipes are not pressure tested at 2 bar, there is a significant risl of damaging seals etc inside appliances. New NG gas systems are tested with air at 50mb IIRC and LPG 75mb (again IIRC as I never install or test anything. I just need to look it up and tick the right box once every five years!)

Boat catches on fire, gas pipe soft solder melts, escaping gas adds to the inferno, big time.

 

 

This could never happen in a house, obviously...

[Col_T]

If you were the BSS man, how could you tell whether a soldered joint has a melting point >450C just by looking?

In my very, very limited experience silver soldered and brazed (both made at > 450C) joints show in a shade of gold, whilst soft solder shows as silver.

[MtB]

I rather went off soft soldered gas joints after I had gas central heating installed by a reputable local heating company. The boiler was installed in an odd space under a mezzanine bathroom, effectively an outside "shed" with limited headroom and space. Anyway one day I went in there to get some stored junk and accidentally leant on the gas supply pipe, which promptly pulled out of a soldered joint and started pouring gas out as I looked at the open end of the pipe! Oops, quickly turned off the gas at the mains. There seemed to be plenty of solder but it was a dry joint or something.

 

 

I'd say the installer was in the habit of fluxing and assembing up lots of joints then soldering them all in one go. This is fatal as it becomes dead easy to miss one out.

 

When I used to install I rapidly learned to flux up and assemble ONE fitting and solder it immediately, then move onto the next. The problem with most plumbers is they tend to be from the umm less academic stock in our skools, and consequently tend to be resistant to learning from experience.

Edited January 13, 2017 by Mike the Boilerman

[bizzard]

Half the trouble is usually due to inadequate heat, so having keeping the heat on the job for too long which solder doesn't like. The same goes for welding, brazing and all soldering.

[nicknorman]

In my very, very limited experience silver soldered and brazed (both made at > 450C) joints show in a shade of gold, whilst soft solder shows as silver.

Brazed, yes. But silver solder is surely .... silver?

[stegra]

 

 

I need to take issue with you here. New LPG gas pipes are not pressure tested at 2 bar, there is a significant risl of damaging seals etc inside appliances. New NG gas systems are tested with air at 50mb IIRC and LPG 75mb

 

Ah. Right. I mean testing newly installed pipework for leaks before any appliances are connected. Stick push-fit stop-ends on the tails and pressure up. You can tell from the gauge if there's a leak but I'd always spray the joints.

Edited January 13, 2017 by stegra

[Guest]

After seeing the effect of solder on copper fittings on the heating system at the school where I used to work, I am right off soldered joints of any sort. I once thought soldered joints were proper joints. The copper had just somehow corroded to being paper thin, and it looked like an effect from the flux I would guess. Thank god it wasn't gas pipework.

[bizzard]

When constructing model copper multi tubular loco boilers you go through several stages using different temperature brazes and silver solders otherwise one would keep melting the previous operation and ruining the whole job. For example, the foundation ring would be brazed first with say Sifbronze. The tube plates, fire and superheater tubes would be silver soldered with, say Easyflow No1. Firebox wrapper, stays ect with, say Easyflow No2, Fittings ect Easyflow No3.

All stages using slightly lower fusing temperatures so as not to melt the previous stage. Similar operation with vehicle radiators and heat exchangers. You would only soft solder low pressure model boilers designed work at no more than about 20psi.

 

 

I need to take issue with you here. New LPG gas pipes are not pressure tested at 2 bar, there is a significant risl of damaging seals etc inside appliances. New NG gas systems are tested with air at 50mb IIRC and LPG 75mb (again IIRC as I never install or test anything. I just need to look it up and tick the right box once every five years!)

 

 

This could never happen in a house, obviously...

After seeing the effect of solder on copper fittings on the heating system at the school where I used to work, I am right off soldered joints of any sort. I once thought soldered joints were proper joints. The copper had just somehow corroded to being paper thin, and it looked like an effect from the flux I would guess. Thank god it wasn't gas pipework.

This is it. The job should have been pickled afterwards or at least scrubbed with soap and water.to remove excess flux.

[Col_T]

Brazed, yes. But silver solder is surely .... silver?

My understanding is that silver solder includes a small percentage of silver, I think to help it flow, hence the name. The resultant joint is not, however, silver coloured. I could post a picture of something I've recently done, but that would just demonstrate how crap I am at soldering!!!

 

Looks to me like Bizzard has considerably more knowledge / experience than me on this subject so maybe he might like to comment?