FHL-VAC® Modules & Panels

FHL-VAC® Insulation Cylinders

One-piece vacuum-formed insulation cylinders for tube furnaces and laboratory equipment.

FHL-VAC® Insulation Cylinders are seamless, one-piece vacuum-formed ceramic fiber cylinders used as the hot-face lining of tube furnaces, laboratory furnaces and cylindrical process equipment. The one-piece construction eliminates joints and gaps, giving excellent thermal uniformity around the tube.

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FHL-VAC® one-piece insulation cylinders for tube furnaces

Up to 1550°C

Key features

Seamless one-piece form — no joints, no hot spots

Excellent temperature uniformity along and around the tube

Ideal for tube furnaces and laboratory R&D equipment

Low mass — rapid ramp rates for research cycles

Custom IDs, lengths and end configurations

Cylinders are supplied as insulation only — a compact, low-mass lining for tube and R&D furnaces operating up to 1550°C.

Custom-Built Parameters

Inner diameter: From ID 100 mm upward · smaller IDs for laboratory units on request
Grades: FHL-M 1150 · FHL-Z 1325 · FHL-HT 1550

Typical Applications

Tube FurnacesLaboratory & R&D FurnacesCylindrical Process EquipmentDiffusion & CVD Equipment

Technical data

Published grade data for FHL-VAC® insulation. 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

Chemical Composition (%)

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

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