Short circuit of electrodes of electrocleaner

When we are electrocleaning we noticed the strap that holds the steam coil to our Koroseal lined steel tank got hot and melted the lining where it was bolted to the top flange. Is it customary to insulate the steam coil as well as the electrodes from grounding to the tank ?

It is common practice to use an isolation connection in the steam line - basically a section of high pressure hose with metallic connectors on both ends. This insulates the steam line from the coil. This prevents currents from outside the tank entering via the steam coil and currents from inside the tank leaving. If the steam coil does become charged in a cleaning tank it will alter the anode to cathode ratio. What this will do I can not say since you did not state if you are doing anodic or cathodic cleaning. In general it is not desirable for the coil to be carrying current.