Both of the lines that are lit up are flexible aluminum couplings. They’re required in some areas as the final connections to the appliances. They’re in line with cast iron gas pipe and fittings. They are much more thin and way better at conducting heat.
Thanks for the clarification, pipes look like copper but might be cast iron.
Still doesn’t fit with the explanation, aluminum has more resistance than copper, but not that much more. The resistance of cast iron is an order of magnitude higher than aluminum. So it would still be the lowest resistance in the circuit and thus the coolest part.
And cast iron is pretty good at conducting heat. Not as good as copper or aluminum, but still pretty good. We’ve been using the material to make pans and pots for cooking because of it’s thermal properties. So the heat wouldn’t just stop at the fitting, but continue on at least some ways.
Moreover it’s physically impossible to get aluminum hot enough to glow like this and still keep its shape. It melts at 600 degrees C, well below the point where something gets red hot, let alone yellow like this. If the aluminum were to be this hot, it would be in a puddle and at risk of burning.
The flexible pipes are normally stainless steel. The main gas line is steel with thick walls so this seems plausible to me. Stainless steel has higher resistance than steel and is so much thinner.
Both of the lines that are lit up are flexible aluminum couplings. They’re required in some areas as the final connections to the appliances. They’re in line with cast iron gas pipe and fittings. They are much more thin and way better at conducting heat.
Source: former HVAC tech
Thanks for the clarification, pipes look like copper but might be cast iron.
Still doesn’t fit with the explanation, aluminum has more resistance than copper, but not that much more. The resistance of cast iron is an order of magnitude higher than aluminum. So it would still be the lowest resistance in the circuit and thus the coolest part.
And cast iron is pretty good at conducting heat. Not as good as copper or aluminum, but still pretty good. We’ve been using the material to make pans and pots for cooking because of it’s thermal properties. So the heat wouldn’t just stop at the fitting, but continue on at least some ways.
Moreover it’s physically impossible to get aluminum hot enough to glow like this and still keep its shape. It melts at 600 degrees C, well below the point where something gets red hot, let alone yellow like this. If the aluminum were to be this hot, it would be in a puddle and at risk of burning.
The flexible pipes are normally stainless steel. The main gas line is steel with thick walls so this seems plausible to me. Stainless steel has higher resistance than steel and is so much thinner.