Pressure rises in the tube.

Heat pipe collectors must be mounted with a minimum tilt angle of around 25° in order for the internal fluid of the heat pipe to return to the hot absorber.

Try wrapping the pipe in tin foil as this keeps the heat in. If not, try cutting styrofoam into the shape of the pipe and attaching it to it, keeping it together with electrical tape.

Used for inspection. Heat numbers make it possible to trace pipe from spools fabricated on a job to material documentation from a given melt. The matching documents will tell when and where the pipe was made, the material used and the pipe grade etc.

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