Is it okay to run copper pipe over a fire when water is running through it?

I am building a pool heater out of a steel box with that fire will be burning inside heating up copper pipes. Is this okay to do or will the solder or copper melt or something?

This Site Might Help You. RE: Is it okay to run copper pipe over a fire when water is running through it? I am building a pool heater out of a steel box with that fire will be burning inside heating up copper pipes. Is this okay to do or will the solder or copper melt or something?

First of all, I'm going on record as being totally against your home-made pool heater contraption. Depending on what you are planning, you might be at risk for contaminating your water, starting a fire, or causing somebody's electrocution! As for your question, the pipes will be fine. The copper will be prevented from ever getting remotely close to its melting point due to the water inside. In fact, this same technique is what is used for flash-water heating systems, such as those in so-called tankless water heaters. However, if you pump water to slowly through the pipes, it is possible for it to locally reach the boiling point where the pipe is hottest. This will increase the pressure in your pipes tremendously, and could cause them to burst. On the other hand, moving the water through the pipes too fast will result in the output stream not being significantly warmer than the input stream. Since the input water will be at different temperatures at any given time of the year, and your homemade heater will most likely not delivery a consistent amount of heat, you can't set this up once statically and expect it to work right. It takes tuning careful tuning, and a control system to regulate both the heat being supplied and the rate at which water is fed through, based on the temperature of the water that leaves the system.

Robert's being a little alarmist in my opinion. You can do this with relative safety. With the pump on the upstream side, the water heating system you describe is never pressurized, so blowing it to smithereens isn't likely. Copper isn't your best bet for very high temperatures but frankly in a homebrew system like you're putting together, very high temperatures probably aren't a big problem. The odds of getting the pipe even hot enough to melt solder isn't likely, and that would be the first point of failure. As long as water's running through it, you probably won't ever get the copper above the boiling point of water.