captainslarty
N/A
Many thanks Vic and all ya guys.. food for thought.
Will buy the appropriate gas pipe in the UK in March.
Joe
Will buy the appropriate gas pipe in the UK in March.
Joe
Any Corgi gas guys here please ? - re gas pipe ?
- Thread starter captainslarty
- Start date
milfordman
Well-Known Member
Hi there VicS,
I was not aware of the details of the Boat Safety Scheme. However 20 years ago I replaced the pipwork on a gas instalation in a macwester 26. On that occasion I replaced like with like, which was 1/4" copper tube approximately 12 ft long which was connected to flex hoses at each end with compresion fittings. I can appreciate that the solder in soldered conection will melt at about 250/280 degrees C, and that a compresion joint would probably maintain it's integrity at that temperature. It does raise an interesting question as to why it is acceptable, infact the usual method in domestic installations, while it is obviously not permitted in a boat.
The one thought that comes to mind is possibly the different gas pressures. Natural gas in domestic installations is set to 10" w.g. Am I right in thinking that Butane is set to a higher pressure. My propane garage heater runs at 1 bar, which is approx 30 times higher than the natural gas.
p.s. My boat cooker runs an parafin.
I was not aware of the details of the Boat Safety Scheme. However 20 years ago I replaced the pipwork on a gas instalation in a macwester 26. On that occasion I replaced like with like, which was 1/4" copper tube approximately 12 ft long which was connected to flex hoses at each end with compresion fittings. I can appreciate that the solder in soldered conection will melt at about 250/280 degrees C, and that a compresion joint would probably maintain it's integrity at that temperature. It does raise an interesting question as to why it is acceptable, infact the usual method in domestic installations, while it is obviously not permitted in a boat.
The one thought that comes to mind is possibly the different gas pressures. Natural gas in domestic installations is set to 10" w.g. Am I right in thinking that Butane is set to a higher pressure. My propane garage heater runs at 1 bar, which is approx 30 times higher than the natural gas.
p.s. My boat cooker runs an parafin.
damo
Well-Known Member
Your house doesn't vibrate as much as your boat - would that have an effect on the integrity of joints?
VicS
Well-Known Member
[ QUOTE ]
Natural gas in domestic installations is set to 10" w.g. Am I right in thinking that Butane is set to a higher pressure
[/ QUOTE ] Normal pressure for butane is 28mb and for propane 37mb (there is also a butane or propane regulator that is set at 30mb)
I make 28mb equal 11.2" water gauge, so not vastly different to the figure you quote for the domestic natural gas supply
The relevant figures for conversion are 1bar = 10^5 Pa and 1" water = 249Pa which I took from Here if you want to check my maths.
I really dont know about the argument against soldering. It may be a complete myth that the reason is that it can melt in a fire. I just quoted the BSS that simply says joints must be made with compression fittings.
Can't comment on your garage heater.
Natural gas in domestic installations is set to 10" w.g. Am I right in thinking that Butane is set to a higher pressure
[/ QUOTE ] Normal pressure for butane is 28mb and for propane 37mb (there is also a butane or propane regulator that is set at 30mb)
I make 28mb equal 11.2" water gauge, so not vastly different to the figure you quote for the domestic natural gas supply
The relevant figures for conversion are 1bar = 10^5 Pa and 1" water = 249Pa which I took from Here if you want to check my maths.
I really dont know about the argument against soldering. It may be a complete myth that the reason is that it can melt in a fire. I just quoted the BSS that simply says joints must be made with compression fittings.
Can't comment on your garage heater.
VicS
Well-Known Member
[ QUOTE ]
Can't comment on your garage heater.
[/ QUOTE ] but I note that there is a 1bar propane regulator (As well as a range of adjustable regulators, which are not allowed in the BSS).
The 1 bar regulator can supply gas at a rate equivalent to 378,500 btu/hr, compared with only 47,500 btu/hr for the 37mb regulator.
Space heaters require so much more gas for their large heat outputs that they have to operate at higher pressures, otherwise very much larger diameter pipework would be necessary.
Can't comment on your garage heater.
[/ QUOTE ] but I note that there is a 1bar propane regulator (As well as a range of adjustable regulators, which are not allowed in the BSS).
The 1 bar regulator can supply gas at a rate equivalent to 378,500 btu/hr, compared with only 47,500 btu/hr for the 37mb regulator.
Space heaters require so much more gas for their large heat outputs that they have to operate at higher pressures, otherwise very much larger diameter pipework would be necessary.
alan_d
Well-Known Member
From the Calor Marine site:
[ QUOTE ]
All joints and unions should be of the compression type not soldered
Soldered joint at risk from electrolytic corrosion, vibration induced failure and melting in the event of excessive heat or fire
[/ QUOTE ]
[ QUOTE ]
All joints and unions should be of the compression type not soldered
Soldered joint at risk from electrolytic corrosion, vibration induced failure and melting in the event of excessive heat or fire
[/ QUOTE ]
VicS
Well-Known Member
[ QUOTE ]
Soldered joint at risk from electrolytic corrosion, vibration induced failure and melting in the event of excessive heat or fire
[/ QUOTE ] The electrolytic corrosion I doubt as solder and copper are not all that far apart in the galvanic series, the surface area of the solder exposed compared with the area that makes the joint will be very small so any corrosion will be at slow rate and the pipework should not be installed where it will be immersed in seawater anyway.
Vibration might be a factor but the pipework is all supposed to be supported so that vibration cannot damage it.
The possibility that solder will melt in a fire is the most valid objection IMO but you then have to answer the point that it is not only, we are told, permissible in domestic natural gas installations but seemingly preferred to compression joints.
Don't get me wrong I am quite happy with compression joints and if the quoted reasons are Calor's objections to soldered joints then that's fair enough. The BSS does not offer any explanation.
Soldered joint at risk from electrolytic corrosion, vibration induced failure and melting in the event of excessive heat or fire
[/ QUOTE ] The electrolytic corrosion I doubt as solder and copper are not all that far apart in the galvanic series, the surface area of the solder exposed compared with the area that makes the joint will be very small so any corrosion will be at slow rate and the pipework should not be installed where it will be immersed in seawater anyway.
Vibration might be a factor but the pipework is all supposed to be supported so that vibration cannot damage it.
The possibility that solder will melt in a fire is the most valid objection IMO but you then have to answer the point that it is not only, we are told, permissible in domestic natural gas installations but seemingly preferred to compression joints.
Don't get me wrong I am quite happy with compression joints and if the quoted reasons are Calor's objections to soldered joints then that's fair enough. The BSS does not offer any explanation.