All posts by Nadine LAURET

HAF 604 certification’s extension

THERMOCOAX is serving the civil nuclear Chinese market for more than 20 years as an authorized exporter for safety related components for nuclear power plant.

We are proud to announce that our HAF 604 certification has been extended by the National Nuclear Safety Administration (NNSA) of People’s Republic of China) till 2022.

This certification initially issued in 2011 has been extended to additional product categories so that THERMOCOAX can now cover a wide range of I&C solutions in term of design and manufacturing of safety related CABLING and SENSORS for InCore and ExCore application.

THERMOCOAX will strengthen its position by providing more cabling for new reactor type like HUALONG, EPR or upgrade solutions for Gen 2 Nuclear Power plant.

作为核电站安全相关部件的授权出口商,THERMOCOAX在中国民用核市场服务了20多年。我们自豪地宣布,我们的HAF604认证已由中华人民共和国国家核安全局(NNSA)延长至2022年。2011年发布的这一认证已扩展到其他产品类别, Thermocoax现在可以在设计和制造用于堆芯和堆芯应用的安全相关电缆和传感器方面涵盖广泛的I&C解决方案。



HAF 604 certification
Copy of the HAF 604 certification

Safety-Related Cabling system for Gen 3+ Reactors: LOCA and Severe Accident-Proofness


As a reaction to the Fukushima disaster, authorities implemented a number of improvements in nuclear power plants (NPP) in order to improve safety.

Some of them are related to the survivability of safety-related sensors located in the containment.

In the event of an accident, the conveyance of a signal from safety-related sensors to the containment wall penetration is key.

Thermocoax is developing specific cabling systems for degraded harsh environments with an NPP design.

The challenge: to design a robust cabling system capable of enduring abnormal or even accident conditions over a lifespan equivalent to the NPP lifespan (i.e., 60 years).

The requirement: Signal transmission lines need to resist normal and abnormal conditions during their entire plant lifespan.

The design of the cabling systems takes into consideration adverse conditions, such as loss of coolant accident (LOCA) and/or severe accident (core melt accident, hydrogen burning), radiation, pressure and seismic conditions and are subject to a stringent test programme following national or international standard requirements (such as IEEE-383 and recommendations) overseen by various authorities.

Once all tests have been successfully passed and the 1E/K1 qualification has been obtained, a stringent manufacturing programme ensures product repeatability and traceability.


Nuclear application

The benefits of Thermocoax technology

 THERMOCOX develops cabling systems based on various technologies, including Mineral Insulated cable technology. No thermal and radiation ageing of the material associated with a specific assembly and manufacturing process results in an extra-long lifespan.

From a technical standpoint, our MI cable technology offers the ultimate performance in terms of withstanding pressure, radiation and temperature compared with other technologies.

No replacement during the lifespan of the NPP is required, resulting in a low cost of ownership; intervention in a contaminated area being a much higher cost factor than the product cost.



THERMOCOAX Nuclear specialises in In-Core and Ex-Core SOLUTIONS, such as:

  • Sensors (neutron flux & gamma flux, temperature measurement and level & flow measurement
  • Cabling systems
  • Heating solutions


THERMOCOAX builds its future on the site of Normand’Innov.

June the 27th was a landmark day for Thermocoax, a global expert in thermal solutions for the advanced markets.

After the acquisition by the Spirax-Sarco Engineering plc group on May the 13th, 2019, the Normandy plant staff was honored by the visit of the Group’s General Manager, Mr. Nicholas Anderson, on the Normand’Innov site for a presentation of the group and its ambitions for Thermocoax, followed by discussions and questions/answers with the teams.

It is on this site, located in Caligny, that will be built the new Thermocoax plant, called “Project One”.

On an area of 12 000m², this building will gather the 4 existing plants to date at Athis Val de Rouvre and Saint-Georges des Groseillers, offering additional floor space. Moreover with 3,500m² dedicated to potential expansion, Thermocoax will be able to fully meet the needs of its growing number of customers in the nuclear, semiconductors and aeronautics sectors.

The afternoon of June 27th, 2019, gathered around Mr Nick Anderson and Mr Dominique Mallet, all the local and regional partners who actively participate in the success of the project.

During an institutional event on the Normand’Innov site, a letter of intent was signed between the Region, the Department, Flers Agglo, Shéma and Thermocoax.

A festive starting point after long meetings and before the rise of a brand new factory for Thermocoax in Normandy.

Thermocoax’ team on site
Partners of the project on site




Spirax-Sarco Engineering plc, which specializes in the control and efficient use of steam, and in peristaltic pumping and associated fluid path technologies, is pleased to announce the completion of the acquisition of Thermocoax, details of which were announced on May 13th 2019.

Nicholas Anderson, Group Chief Executive of Spirax Sarco, said:

« We have developed an exciting strategy for Thermocoax, which will sit within the electrical process heating business of our Group, which was created in 2017 with the acquisition of Chromalox in the United States. Our goal is to elevate the position of both brands in their markets by combining the potential of Thermocoax with that of Chromalox, while strengthening the Thermocoax brand worldwide. »

About Spirax Sarco

Spirax‐Sarco Engineering plc is a thermal energy management and niche pumping specialist. It comprises three world‐leading businesses: Steam Specialties, for the control and management of steam; Chromalox, for electrical thermal energy solutions; and Watson-Marlow, for peristaltic pumping and associated fluid path technologies. The Steam Specialties business and Chromalox provide a broad range of fluid control and electrical process heating products, engineered packages, site services and systems expertise for a diverse range of industrial and institutional customers.  Both businesses help their end users to improve production efficiency, meet their environmental sustainability targets, improve product quality and enhance the safety of their operations.  Watson‐Marlow Fluid Technology Group offers the ideal solution for a wide variety of demanding fluid path applications with highly accurate, controllable and virtually maintenance free pumps and associated technologies.

The Group is headquartered in Cheltenham, UK, has strategically located manufacturing plants around the world and employs over 7,800 people, of whom over 1,600 are direct sales and service engineers.  Its shares have been listed on the London Stock Exchange since 1959 (symbol: SPX) and it is a constituent of the FTSE 100 index.

Further information can be found at


Visit us at Le Bourget Trade show (June 17-21, 2019), Hall 2B, Booth D40

The Latest Innovative Solutions for Temperature Measurement Sensors Heating Systems



Thermocoax Pedigree

For 25 years, THERMOCOAX has been a leading global figure in designing, developing and manufacturing heating systems for the Aerospace market.

We provide solutions for:

– Ground applications:

  • R&D programs in collaboration with institutes
  • Ground test equipment

-Flying models:

  • On board satellites, 50- & 100-volt communications satellites, low orbit constellations, long range space probes
  • On board planes, helicopters

– Defense

  • Armored Vehicles
  • On board fighters, long range missiles
  • Submarines


Our solutions include:

  • Heating systems for space propulsion, satellite heating management, shape-memory devices
  • Anti-icing system for pitot tubes, AoA tubing, Ta tubing, drain masts
  • Bleed Air Overheat and fire detection systems
  • Brake temperature monitoring system
  • Engine temperature measuring system
  • Oil and fuel temperature measuring system
  • Heating solutions for composite industries (curing, shaping, bonding…)


Heated Waste Water Drain Mast

To remove unnecessary weight, the greywater from the washbasins is ejected outside the plane.

Most airplanes are equipped with two drain masts, one at the front and one at the rear near the washbasins.


  • Heritage:
    • Falcon Jet : F900, F2000, F7X
    • A220, Ejet1&2


  • Technology with self-regulation or equipped with switches
  • Resin shell
  • Power: from 28 volts to 115 volts
  • Power dissipation: from 20 watts to 250 watts
  • RTCA/DO160



Brake Temperature Monitoring System

The brake thermocouple gives the brake temperature in real time and can be transformed into a “hot brake” alert for the pilot when the value goes over a predetermined temperature threshold.

It provides the cockpit with important information regarding the temperature of the right and left brakes. If the difference is too great, asymmetric brake friction can occur, leading to difficulties in maintaining constant heading and keeping speed under control.

Thanks to this system, the pilot receives a clear “Go/Don’t Go” message for the takeoff authorization. The brake thermocouple indicates that if an emergency brake needs to be carried out during the takeoff operation, the brake will have its full efficiency so that it can stop the aircraft on time for the safety of all passengers.




  • Heritage:
    • Airbus 350
    • Embraer E-jet
  • Soon to be available for:
    • IRKUT MC21
    • Mitsubishi MRJ
    • COMAC C919
    • Eurofighter
  • K type thermocouple
  • Class1
  • Dielectric 500V
  • Ø5 up to 4.75mm
  • RTCA/DO160


Heating System for Space Propulsion

Electrical and chemical thrusters are small rocket engines used for orbit raising as well as attitude, trajectory and orbit control for satellites and spacecraft

The main purpose of pre-heating thrusters is to improve their performance at startup and to increase the lifetime of their components.




  • E3000 100volts
  • Prisma
  • Smart 1
  • Planet constellation
  • Many more


  • 100mN to 400 Newton thrust
  • 3 to 100 watts under 28 to 55 volts
  • Redundancy made with 2 heating loops
  • Dielectric 500 volt
  • Up to 1600°C


SMA heater

In order to accomplish their mission, spacecrafts require a variety of mechanisms whose typical functions are designed for deployment, articulation, positioning and displacement operations.

However, pyrotechnic separation nuts, paraffin actuators and certain other devices are no longer compatible with satellite requirements due to shock wave generation and potential contamination risks.

Non-pyrotechnic devices make use of SMA technology and are equipped with internal heating elements, offering slow and smooth responses, cleanliness and good vibration & shock resistance.



  • Single one-time use Valve
  • Hold Down & Release Mechanism


  • Data:
  • Cable Ø1 mm 28VDC
  • 2 to 10 watts


  • Cable Ø5mm, 28volts:
    • 30 watts with 1 loop activated
    • 60 watts with 2 loops activated


Test List for Qualification Program

THERMOCOAX manages and conducts the qualification test programs in accordance with our customer’s specification.

Our engineers design the QTP for customer approval prior to running the test.

Most of the tests (thermal, humidity, electrical, etc.) are performed in HERMOCOAX’s labs.

Tests requiring heavy equipment (vibration, acceleration, shocks etc.) are subcontracted to external laboratories or supported by our customers with the complete propulsion system.

  • List of possible Qualification Test:
  • Vibration
  • Acceleration
  • Mechanical shock
  • Pyrotechnic shock
  • Helium leak
  • Burn-in
  • Humidity
  • Hot Firing
  • Electrical cycling
  • Thermal cycling
  • Lead attachment
  • Dielectric
  • Destructive physical analysis
  • X-ray examination


THERMOCOAX is a major competitor for onboard heating solutions for electrical heating systems and is proud to be a part of challenging international space programs.

THERMOCOAX focuses on high quality heating products for maximum stability and repeatability during operation. For 20 years we have understood our customers’ challenges to manufacture spacecrafts to create a better life for human beings.

Extensive new constellation programs are currently in construction.

THERMOCOAX is now ready to support the market with highly reliable and efficient heating elements.



THERMOCOAX Nuclear department : 2018 highlights

DISCOMS project: a happy ending with promising results.

Following the FUKUSHIMA disaster, the French government decided to allocate some of its budget  to stimulate R&D in the field of nuclear safety and radiation protection.

investir l'avenir logo

The DISCOMS (DIstributed Sensing for COrium Monitoring & Safety) project aims at developing an innovative under-vessel remote monitoring instrumentation to improve NPPs safety in operation.

A team of reputable Research Institutes, universities and Industrial companies was formed to address the development of a remote monitoring solution able to improve the safety of Nuclear Power Plants and strengthen the third containment barrier in case of a severe accident with a reactor breakthrough and corium release.

Long-length Self Powered Nuclear Detectors have been developed to identify the reactor core debris progression, the erosion of the concrete floor, as well as to monitor the corium cooling.

After multiple simulations and theoretical validations, a complete system (sensors + electronics) has been tested with corium and has demonstrated its technological readiness.


Safety Culture

 Nuclear culture award


THERMOCOAX was distinguished with a  Safety Culture award from Rolls Royce. In 2019, THX will continue its effort to improve working practices and place safety as a main priority.


 Skills & Knowledge Management

 At the WNE, THERMOCOAX was nominated for an award in the “Skills & Knowledge Management” category.

In its Quality Assurance Manual, THERMOCOAX takes into account the requirement  presented in the ISO 19443.

One goal: anticipate chain standards for future nuclear supply today to maintain the highest standard of safety culture, quality and competitiveness.

“During Rolls Royce Nuclear supplier days” sounds unnatural in English but difficult to amend without knowing meaning of source text.


Small summary, in words and images, on the milestones of 2018 and the beginning of this year in Aeronautic market

THERMOCOAX equips Airbus A220 with 2 drainage mats for front / rear galleys. With already 536 planes in the AIRBUS orderbook, we are working our ramp up organization. With an ambitious target of several thousands of aircrafts over the next 20 years, the A220 platform would be one of the most successful program THERMOCOAX invested in.


At the ILA Berlin event at the end of 2018, Stéphane Fourrez, as part of the European NIPSE programme, presented the results of work on a new fire detector for the next generation of avionics engines. Stéphane presented the methodology and the technical results to an international expert audience of international experts and answered many questions.

THERMOCOAX was invited to participate in the “Passive Component” symposium organised by the European Space Agency at the end of 2018.

Among thirty odd posters, the one made by Alexis Brodin and Xavier Potiron won the grand prize-what a proud achievement for both of them, and for THERMOCOAX.


In Autumn, 2018, at the CAMX event, the THERMOCOAX US team presented the heating products for composite applications designed for aviation and other industries in general.



High-End Thermal Solutions for Semicon Front-End Processes

In the semiconductor sector, machine-manufacturers at different stages of the wafer manufacturing process are looking for high-performing heating solutions that meet cutting-edge specifications in terms of design, uniformity, repeatability and lifetime but that are also able to withstand very corrosive environments under ultra-high vacuum and with ambient temperatures above 100°C.

THERMOCOAX’s expertise is in responding to strict specifications and in designing tailor-made high-performing thermal solutions from mineral insulated cables.

Our engineering know-how, our prototyping capacity and our knowledge of mineral insulated cables allow us to offer unique solutions to our customers.

We are also able to develop complex mechanical parts that incorporate our heating elements.

Our strength is that we master all these processes internally with a factory certified “Copy exact” dedicated to SEMICON applications for wafer manufacturing processes: high precision machining, welding, soldering, tests and qualifications, control, ….

Over the last few months, THERMOCOAX has developed an innovative, reliable and efficient solution to heat a system inside a vacuum chamber.

The challenge of this project was combining two thermal systems that had to be integrated into the customer’s final system, in an ultra-high vacuum and corrosive environment at high temperature.

The first thermal system that we had to develop was a kind of heating element coiled on a mandrel

The solution was complex because we had to meet critical specifications such as:
• The limitations and dimensional tolerances of the heater
• Critical operating temperature of 800°C
• Achieving a 10% power distribution uniformity – Several heating areas have been designed with different power densities
• Operational guarantee > 5 years, in ultra-high vacuum with a corrosive environment

We designed 6 different concepts and compared these solutions in order to select one.

THERMOCOAX chose a design with EC wound / brazed on a metal support which was mass-produced in line with a specific process.

Progress achieved – results achieved – originality of the chosen solution

This design, which at first glance looks like a heating cartridge, is innovative in its design because it has a fully wound heating element integrated in a mandrel by a process developed by THERMOCOAX.

The expected performances and lifetime results were validated during the qualification phase of the prototypes.

This all-encompassing design by THERMOCOAX targets many areas, with its performance advantages, its low cost design and its long lifetime performance.

The second thermal system is a complex assembly of a 3D design metal part with high temperature heating elements

Problems to solve

Being able to assemble complex metallics with a demanding dimensional specification and an operating temperature that can reach up to 800-900°C.

This temperature is near critical, especially when specifying a lifetime greater than 5 years.

We had to resolve the problem of complex machining.

It was also necessary to take the deformations caused by the machining into account, as well as the deformation from the welding and brazing processes.

The design and manufacturing method was developed entirely by THERMOCOAX to achieve a feasible design suitable for high volume manufacturing and minimizing the risk of non-compliance with dimensional or functional specifications.

We worked on raw material (304L) and evaluated and selected the material that was the most cost / quality / time effective.
For the metallic parts we evaluated: Full mass / forged / foundry material.

The other challenge with these pieces was treating them on the surface so that the highly corrosive liquid in the vacuum chamber would not stick to them.

After much research and testing we identified a substance that has very good anti-wetting properties and could be used for this type of application.

Work has also been done to validate the most suitable deposition process (PVD or CVD).
We finally selected the best deposit solution that operates in up to 600°C.


THERMOCOAX Turbines Solutions Long-life Thermocouples

Thermocoax announces a new thermocouple generation :

  • 24 000 operation hours in heavy duty gas turbine
  • Exceptional resistance to vibration, thermal stress, corrosion…
  • Already demonstrated in air-cooled 446MWatt machine
  • 37 gas turbine  already equipped
  • 18 currently under operation
  • 1.2 Million hours cumulated
  • 699 starts


Technical application of long-life thermocouples

The gas turbine frames market is a challenging business. On the one hand, the frames are more and more high-tech and expensive and on the other hand, the energy producer is driven by low electricity production prices. To make them both compatible, gas turbine frames have to be reliable to minimize operation disruption and to offer longer periods without maintenance. Therefore, providing thermocouples with an increased lifespan decreases the downtime of the turbine, thereby significantly reducing the maintenance costs.

Required Benefits

One of the key aims of the OEM GT is to find high-accuracy thermocouples on the market that are able to perform in harsh environments and work for 24,000 operating hours without failing.

Thermocouples installed in exhaust gas lines are exposed to corrosion, vibration, thermal expansion and much more.

Thermocoax’s Solution: Design a thermocouple that is out of the excitation bandwidth

Based on the capitalized cumulative return of experience in several fields, such as aeronautical, nuclear and oil & gas, THERMOCOAX has developed a vibration absorber that is secured to the thermocouple to avoid premature breaking when the thermocouple is subject to vibrations and thermal expansion. This solution is protected by a patent.

The invention with the patent number 63638FR/CZ/BB – 17 58061 is a vibration absorber that is secured to the thermocouple cable and is made to fit inside the screen/thermowell.

The number and size of the absorbers depend on the gas turbine specification in terms of vibration, acceleration and thermal cycles.

To demonstrate the advantage of this new design and its ability to reach 24,000 operating hours, THERMOCOAX has undertaken simulation and experimental testing:

1.1 Simulation: Comparison between a thermocouple with and without a vibration absorber

Input data:

  • Ø ≈ 3mm Type K thermocouple with 316L SS sheath
  • Length ≈ 500mm insertion length in SS316L thermowell
  • Temperature 870°C
  • Frequency range: 0 to 250Hz, mean value 100Hz
Long-Life TC Standard TC
Resonant Frequency of the TC 174Hz 68 Hz
Stress produced by the Resonant Frequency of the TC 11.1MPa 450MPa
Number of cycles made before Breaking of TC at its Resonant Frequency 9×109 40
Life-span at the Resonant Frequency of the TC 2.1×109 days 10 days

1.2) Field test results: Comparison between a thermocouple with and without a vibration absorber

  • Ø ≈ 3mm Type K thermocouple with 316L SS sheath
  • Length ≈ 300mm insertion length in SS316L thermowell
  • Temperature 900°C
  • Frequency range: 0 to 1000Hz,
Long-Life TC Standard TC
Resonant Frequency of the TC 68Hz 174Hz
Life-span during the Endurance Test Still works after


Stops working before 3000h


The test is still ongoing. We can already say that the field results demonstrate the extraordinary positive impact on the reliability of the gas turbine. This new long-life thermocouple lasts 7 times as long as a standard thermocouple.

For the powerplant operator, the cost saving is at least 150,000 euros in thermocouples for every 20,000 hours of operation because there are no costs incurred from the frame shutting for unexpected maintenance.



For 60 years THERMOCOAX has been a worldwide key player in designing, developing and manufacturing thermocouple temperature sensors for industrial and aircraft gas engines.

With our custom-made Mineral Insulated Cable, we are providing our customers with solutions for:

  • Development applications:
    • R&D programs with institutes
    • Ground, aero & industrial test equipment
  • Production models:
    • Thermocouples in harsh environments with an installed base of over 300,000 thermocouples:
      • Heavy duty gas turbine
      • Stroke engine
      • Steam turbine
    • Thermocouples for helicopter engines with 15,000 units installed
  • Thermocouple characteristics:

Thermocouples are produced with Class 1 custom-made cables with a diameter from 0.25mm up to 6mm.

Single (2 wires) or duplex design (4 wires)
Types K and N are the most used in the industry.

Thermocoax recommends type N thermocouples for a working temperature of between 600°C and 1100°C, which offer a smaller drift compared to type K.

We have several sheath alloys available:

  • Stainless Steel
  • Inconel
  • Haynes
  • Platinum
  • Tantalum



THERMOCOAX Calibration Lab

100% of the mineral insulated cable and finished thermocouples are controlled in the calibration lab.

  • Capabilities

Fixed points

TEMPERATURE -Thermocouple
Calibration purpose Mesurand Measurement range Best calibration uncertainty Measurement principle/Method reference (*) Calibration tools (reference, Equipement) Activities in Lab and/or on site
Thermoelectric couple Temperature                                                                              Electromotive Force Signal Voltage Melting ice point 0,00°C ±0,3°C Method by comparaison at a fixed point / PP200D010 Rev06 Water triple, Sn, Pb, Zn cells Platinum resistance thermometer multimeter                                                  Melting ice point Lab
Water Triple point 0,01°C ±0,3°C
Sn Melting point 231,928°C ±0,5°C
Pb melting point 327,46°C ±0,5°C
Zn melting point 419,46°C ±0,5°C
Sb freezing point 630,62°C ±0,9°C Sb Cells                                              Thermoelectric couple S Type Multimeter                                              Melting ice point


By comparison

TEMPERATURE -Thermocouple
Calibration purpose Mesurand Measurement range Best calibration uncertainty Measurement principle/Method reference (*) Calibration tools (reference, Equipement) Activities in Lab and/or on site
Thermoelectric couple Temperature                                                                                                                                                                        Electromotive Force Signal Voltage -40°C to 0°C ±0,4°C Method by comparison / PP200D022 rev 08 Ethylene/Glycol constant temperature bath                           Platinum resistance thermometer Multimeter                                     Melting ice point Lab
0°C to 80°C ±0,3°C
50°C to 200°C ±0,4°C Oil Constant temperature bath Platinum resistance thermometer Multimeter                                                 Melting ice point
150°C to 400°C ±0,5°C Bath of melted salts Platinum resistance thermometer multimeter
400°C to 500°C ±0,6°C
500°C to 700°C ±1,3°C Tubular furnace                                    S type thermoelectric couple Multimeter                                             Melting ice point
700°C to 1100°C ±1,4°C
1100°C to 1200°C ±1,6°C
1200°C to 1300°C ±2,1°C
1300°C to 1500°C ±2,4°C

Heated cable inlet for climatic chambers

Target market :

Manufacturers and operators of climatic chambers.

Challenge :

Prevention of condensation at the cable inlet inside and outside of climatic chambers.

Description of the problem without a heated cable inlet :

Condensation at the cable inlet due to climatic differences between the inside and the outside of the chamber.

Condensation on the measuring cables inside and outside of the temperature test chamber when using a standard inlet.

Risk :

High financial risk if long-term climatic tests have to be cancelled because of condensation in the climatic chamber. Condensation damages the test materials and affects the climate regulation in the chamber.

Solution :

Heated cable inlet from THERMOCOAX Isopad® GmbH. A standard inlet with geometric properties, the best possible sealing and a heated area inside of the cable inlet.

Test results with a heated cable inlet :

Decrease in the amount of condensation formed inside the climatic chamber by approx. 95% and by 100% outside of the climatic chamber!

The risk of failure is extremely reduced because there are hardly any condensation drops in the chamber (airflow can spread the drops onto the test material).

No water on the floor outside the chamber. The risk of slipping is eliminated, thereby extremely reducing the risk of accidents !