FHL-VAC® Modules & Panels

FHL-VAC® Embedded Heating & Insulation Segments

Cylindrical segments with the heating element embedded in the wall — complete heated cylinders.

FHL-VAC® Embedded Cylindrical Insulation Segments integrate the heating element inside the cylindrical insulating module. Heat radiates inward to the workload through the formed window while the module wall blocks losses outward — a complete heated cylinder in segmented, easy-to-install form.

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FHL-VAC® embedded cylindrical insulation segment with integrated heating element

Up to 1050°C

Key features

Heating element embedded within the cylindrical module

Uniform 360° heat radiation toward the workload

Segmented construction — simple handling and replacement

Fe-Cr-Al or Ni-Cr elements to suit duty temperature

Dramatically lighter than castable-lined cylinders

Custom ID, length, wattage and grade combinations

These segments are the fastest route to reline or build pit, bell and split furnaces with uniform circumferential heating, and are manufactured from ID 100 mm upward in all FHL-VAC® grades.

Custom-Built Parameters

Thickness: 90 / 100 / 125 mm
Inner diameter: From ID 100 mm upward

Typical Applications

Pit FurnacesBell FurnacesSplit FurnacesWire & Strip Annealing Covers

Embedded cylindrical insulation panel — close view of element groove

Technical data

Published grade data for FHL-VAC® insulation and FHL® heaters. Values are typical for the grade; confirm design values with our engineers for your duty cycle.

Technical Data — FHL-VAC® Modules & Panels

Parameter	FHL-M 1150	FHL-Z 1325	FHL-HT 1550
Classification Temperature (°C)	1260	1425	1650
Max. Continuous Working Temp. (°C)	1150	1325	1550
Density Range (kg/m³)	200 – 240	200 – 240	200 – 240
Linear Shrinkage % (24 h at Continuous Working Temp.)	< 1	< 1	< 1

Thermal Conductivity (W/mK)

Mean Temperature	FHL-M 1150	FHL-Z 1325	FHL-HT 1550
At 200°C	0.065	0.065	0.065
At 600°C	0.13	0.13	0.14
At 1000°C	0.27	0.28	0.24
At 1200°C	0.40	0.38	0.33
At 1300°C	0.48	0.47	0.39
At 1400°C	—	0.53	0.45
At 1500°C	—	—	0.51

Chemical Composition (%)

Component	FHL-M 1150	FHL-Z 1325	FHL-HT 1550
Al₂O₃	47	37.5	66
SiO₂	53	49.5	33
Zr	—	13	—

Physical & Mechanical Properties of FHL-MULTICORE® Heating Elements

Other elements present in small quantity. Values are typical for the grade; confirm design values with our engineers for your duty cycle.

	Fe-Cr-Al Heating Element		Ni-Cr 80 Heating Element
Property	Alloy 1	Alloy 2	Ni-Cr 80
Standard Chemical Composition (%)	Al 5.0 · Cr 23 · Fe 72	Al 6.0 · Cr 23 · Fe 71	Cr 19–21 · Fe < 1 · Ni ≥ 77
Max. Duty Temp. of Heating Element (°C)	1320	1420	1150
Electric Resistivity (Ω·mm²/m)	1.35 ± 5%	1.45 ± 5%	1.08 ± 5%
Density (g/cm³)	7.25	7.1	8.3
Expansion from Thermal Factor (K⁻¹)	15.1 × 10⁻⁶	14.8 × 10⁻⁶	17.6 × 10⁻⁶
Thermal Conductivity at 20°C (W/m·K)	13	13	13
Specific Heat Capacity at 20°C (kJ/kg·K)	0.46	0.46	0.46
Melting Point (°C)	1500	1500	1400
Hardness Hv	200 – 240	200 – 240	180 – 200
Electric Resistance Temp. Coefficient	33 × 10⁻⁶	15 × 10⁻⁶	58 × 10⁻⁶
Increase from Oxidation 1200°C (mg/cm²·h)	0.05	0.05	0.25 or less
Tensile Strength MPa (kgf/mm²)	650 – 900 (65 – 90)	650 – 900 (65 – 90)	700 – 900 (70 – 90)
Magnetic Properties	Magnetic (Curie point 600°C)	Magnetic (Curie point 600°C)	Non-Magnetic