Abstract: A cartridge heater and method of manufacturing same. In one embodiment, the cartridge incudes a sheath having a first end and a second end. The first end of the sheath forms a seat. An elastomeric bushing is swaged against the seat such that it forms a mechanically bonded seal substantially preventing moisture egress into the cartridge heater. A heating element is also disposed in the sheath and is connected to leads protruding from the bushing. The heater includes crushable insulation material disposed within the sheath.

Abstract: A cartridge heater and method of manufacturing same. In one embodiment, the cartridge includes a sheath having a first end and a second end. The first end of the sheath forms a seat. An elastomeric bushing is swaged against the seat such that it forms a mechanically bonded seal substantially preventing moisture egress into the cartridge heater. A heating element is also disposed in the sheath and is connected to leads protruding from the bushing. The heater includes crushable insulation material disposed within the sheath.

Abstract: A cartridge heater for high-voltage applications is disclosed. In one embodiment, the cartridge heater is substantially elongate and cylindrical, and comprises an outer stainless steel sheath having an outside diameter on the order of one-half inch or less. Within the outer sheath is a resistive heating element coiled around an inner, electrically insulating wind core. A substantially hollow cylindrical core sleeve is disposed around the heating element and wind core, electrically insulating the heating element from the outer sheath. In one embodiment, the core sleeve is composed of pre-compressed magnesium oxide.