Why is the cooling water pipe of the induction melting furnace not electrified?

The induction melting furnace uses cooling water. The water in the water pipe is actually conductive, but the cooling water pipe of the induction melting furnace is generally relatively long, and the resistivity of the water is very large, which is equivalent to passing a large resistance, and the voltage drops a lot, which is less noticeable. , As if there is no electricity. This is the same as the test pencil: if there is electricity, the neon bulb inside will light up, but there is no feeling when you touch the metal part of the test pencil.