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Jun 21, 2023
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Hi, names Don Nicholson. Semi retired mechanical & electronic engineer. currently playing with a small steam driven water pump. (1/2" bore 1/2" stroke) that I picked up for $40 at a country market. Have got it working on compressed air after lapping the face of the steam valve to remove corrosion pitting. Now looking to build a tiny boiler for it. Cant seem to find a cheap source of 4" copper pipe but have a hand held propane cylinder the right diameter. Flushed it out & cut it to length. Will source a bit of copper flat to make a bottom for it & some 1/2" copper for a flue. I intend to silver solder it together & pressure test it to 3 times working pressure of 50 psi. I will dish the copper about 1/2" & turn over 1/4" lips to give plenty of overlap for the silver solder.
A couple of questions I hope someone can help with. It is an early cylinder with the screw in relief valve on the top. does anyone know what the set pressure is & the thread on it?
Any suggestions or criticisms will be taken seriously


  • Steam pump & boiler shell.jpg
    Steam pump & boiler shell.jpg
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