High-Temperature Heat Pipes
ACT (Advanced Cooling Technologies)
Alkali metal heat pipes operating from 400°C to 1,100°C using potassium, NaK, or sodium in stainless steel or Haynes envelopes for nuclear space power, solar thermal, and hypersonic applications.
Typed specifications20 values
Discloses 4 of 7 fields engineers filter by in this category (category median 2).
- Envelope (L×W×H)
- 0.5 mm min · Typical diameter · datasheet p.2 5 mm max · Heat Transport Length | 4 mm max · Typical diameter
- Operating temperature
- 126.9–826.9 °C typical operation of high-temperature heat pipes · datasheet p.1 -46.3 °C min | 1 100 °C max | -46.3–553.6 °C typical performance envelope, configuration-dependent
- Product type
- heat pipe high-temperature alkali metal heat pipes · datasheet p.1
- Material
- stainless steel and nickel-based superalloys (Inconel, Haynes); R&D on refractory metals, FeCrAl datasheet p.1
- Length
- 5 000 mm max · heat transport length up to 5 m · datasheet p.2
- Working fluid
- other cesium (380 °C to 600 °C) · datasheet p.1 other lithium (greater than 1000 °C) | other potassium (400 °C to 1000 °C) | other sodium (500 °C to 1100 °C) | other sodium-potassium NaK (500 °C to 900 °C)
- Outer diameter
- 12.7 mm min · typical diameter of 0.5" to 4-5" · datasheet p.2 127 mm max · typical diameter of 0.5" to 4-5"
- Wick type
- none (thermosyphon) thermosyphons and loop thermosyphons rely purely on gravity · datasheet p.1
- Envelope material
- stainless steel common envelope material · datasheet p.1 other nickel-based superalloys (Inconel, Haynes)
Each value is typed with its unit and measurement condition and cites the datasheet page it was taken from. Nothing is guessed: a field that is absent here has not been published by the manufacturer. machine-extracted ✓ checked by NewSpace Market ✓ manufacturer confirmed by the manufacturer.
As published by the supplier8 lines, in the manufacturer's own wording
- Potassium operating range
- 400–1,000°C
- Nak operating range
- 500–800°C
- Sodium operating range
- 500–1,100°C
- Envelope materials
- Stainless Steel, Inconel Alloy 600, Haynes
- Ifl temperature uniformity
- ±0.1°C
- Hpbc temperature uniformity
- 0.05–0.1°C
- Pchp set point stability
- ±0.01°C
- Quality certification
- AS9100, ISO 9001
About
ACT’s High-Temperature Heat Pipes use alkali metal working fluids — potassium, NaK alloy, and sodium — to operate across the 400°C to 1,100°C temperature range, far beyond conventional copper-water or aluminum-ammonia devices. These heat pipes use superalloy envelope materials including stainless steel, Inconel Alloy 600, and Haynes.
ACT collaborated with NASA on the Kilopower space fission power project beginning in 2015, developing alkali metal heat pipes to support small fission reactors for space transportation and surface power. Derived product lines include Isothermal Furnace Liners (±0.1°C uniformity), Heat Pipe Blackbody Cavities (0.05–0.1°C uniformity), and Pressure Controlled Heat Pipe furnaces (±0.01°C stability). Space applications include nuclear reactor heat transport, solar thermal receivers, and thermoelectric generator heat sources.
Documentation
- NUC-CS-01_HighTempHeatPipesForNuclearPower-CutSheet_V1_2026-01-07_Web.pdf PDF source: www.1-act.com ↗
Need the full ICD, test reports or a specific revision? Ask the supplier directly.