How to bend the electron tube in the corner?

What you should say is PVC pipe. There are special bending springs, which are sold everywhere. Buy a corresponding size, tie it with a rope, insert it into the pipe and bend it slightly larger than you want, then pull out the spring. Galvanized pipe bender. Large-diameter pipes filled with sand will not bend when bent.

Generally, the bending radius should not be less than 6 times of the pipe diameter, and when laid in concrete, it should not be less than 10 times of the pipe diameter. The bending angle of the pipe should not be less than 90 degrees.