The JHR-22 sheathed electric heater offers two installation types: flange connection and threaded connection. The flange standard covers DN50 to DN150, accommodating different nozzle specifications. When selection prioritizes maintenance convenience, the flange solution is more operable during heat exchange tube bundle cleaning and insulation resistance retesting, as it does not require rotating the entire heater body during disassembly; the threaded connection demands higher nozzle concentricity and requires checking seal face wear after repeated assembly and disassembly.
Compared with conventional immersion electric heaters, the sheathed structure isolates the heating element from the medium. The JHR-22 allows replacement of the heating core without draining the pipeline—simply remove the sheath end cover to extract the core. This feature reduces downtime maintenance costs, but also requires that the gap between the inner wall of the sheath and the heating core be maintained within the design range. An excessively large gap reduces heat transfer efficiency, while too small a gap increases assembly difficulty.
Routine maintenance should focus on whether the temperature resistance grade of the flange gasket matches the medium operating conditions, as well as scaling on the outer wall of the sheath. The scale layer significantly increases thermal resistance, causing the surface temperature of the heating core to rise. It is recommended to record insulation resistance and circuit resistance during periodic overhauls. If the circuit resistance deviates from the initial value beyond the allowable range, check for oxidation of wiring terminals or internal open circuit of the heating core.
For corrosive media, the sheath material and flange sealing face type must be confirmed during the selection stage. Threaded connections are not suitable for frequent disassembly and cleaning scenarios. The maintenance cycle should be determined based on medium cleanliness and operating temperature; under high-temperature conditions, the inspection interval may be appropriately shortened.
