Product Overview
The tubular element is the basic building block of all industrial heaters. A nickel-chromium resistance wire is centered and surrounded by high-purity crystalline magnesium oxide (MgO) powder, enclosed in a stainless-steel, carbon-steel, or Incoloy sheath, sealed at both ends with silicone or ceramic. The compacted MgO both insulates and conducts, keeping the wire in good thermal contact with the sheath at high temperature.
Elements bend into U, W, coil, or custom contours following equipment profiles, with a minimum bend radius about 2.5× the tube diameter. Tube diameters range from Φ6.5 to Φ20, with Φ8, Φ10, and Φ12 most common. Surface load is chosen by medium and temperature: 4–8 W/cm² for water, 2–4 W/cm² for oil, 1–3 W/cm² for air.
Lead exits include threaded studs, lead wire with ceramic beads, and blade terminals, customizable to customer wiring. Each element is tested for insulation resistance, hi-pot, and power tolerance within ±5%; multi-element assemblies above 15 kW are resistance-matched for balanced loading.
Construction Features
- Tube diameter Φ6.5 – Φ20, bendable into U, W, coil, and custom shapes
- Ni-Cr 80/20 resistance wire, MgO powder purity ≥96%
- Sheath options: 304, 321, 316L, Incoloy 840/800, titanium
- Single element 0.5 – 15 kW, power tolerance ≤±5%
- Surface load by medium: water 4–8, oil 2–4, air 1–3 W/cm²
- Per-element insulation, hi-pot, and resistance tests; test records available
Technical Specifications
| Single Power | 0.5 – 15 kW |
|---|---|
| Rated Voltage | 110V – 480V |
| Tube Diameter | Φ6.5 / Φ8 / Φ10 / Φ12 / Φ16 / Φ20 mm |
| Sheath Material | 304 / 321 / 316L / Incoloy 840 / 800 / Titanium |
| Max Temperature | 800°C (by material) |
| Surface Load | 1 – 8 W/cm² |
| Insulation Resistance | ≥ 500 MΩ (cold) |
| Withstand Voltage | 1500V / 1 min no breakdown |
The table lists typical configuration ranges. Special pressure, temperature or media conditions require re-checking; final parameters are confirmed by the approved drawings and technical agreement.
Typical Applications
- Ovens and drying equipment
- Molds and hot plates
- Water and oil tanks
- Air ducts and AHU coils
- Packaging sealers
Information Needed for Selection
- Medium name, concentration, and whether it contains particles
- Total medium volume or circulation flow rate
- Initial and target temperature
- Required heat-up time
- Vessel or pipe size and material
- Supply voltage, phases, and available capacity
- Installation environment and hazardous-area requirements
- Connection standard and mounting orientation
