The RCA TTU-25B UHF TV transmitter had over 3000 volts on the plates of the 25 KW and 12.5 KW output tubes, while the water chiller and pump were grounded. Some of those transmitters have been in daily use for over 50 years. The purity of the water is very critical. Special rubber pipe was used to insulate the two from each other, while everything else was soldered copper pipe, up to 4 inches diameter.