The Specialists for Thermo Fluid Control


Heavy-duty machines, all-rounders and moving machines ...

Our products:

  • Thermal working elements
  • Oil temperature regulators for pipework installations
  • Oiltemperature regulators for housing installation
  • BTM - Multifunction - oiltemperature regulators
  • Inserts for oil temperature regulation
  • Coolant temperature regulators
  • Thermoswitches and thermosensors
  • Housing thermostats
  • Heavy-duty thermostat inserts

Thermo Fluid Control

Hot and cold, precisely regulated – temperatures safely under control.

ACS components are primarily used in oil and water glycol circuits for machines, aggregates or systems.

For more than 20 years, we have focused on the optimisation of temperature levels in liquid cooling circuits. Components from ACS allow for great energy savings in a system.


A product is only as good as the components that it contains

The reason of our worldwide success in the field of cooling and regulating technology is based on our quick and flexible order handling, our technical application know-how and last but not least on our high quality products.

Due to an optimized and slim sales organization we can keep prices low for you.


Follow our latest achievements

Christmas greetings 2021

Dear customers, Our goal is to infect our customers with our enthusiasm for our products. Your great interest in the past year shows us that we have succeeded. Thank you very much - for us this is an important incentive to offer you the best quality again at a fair price / performance ratio in 2022. We wish you a happy, prosperous year 2022!


A simple principle

Energy-independent thermo regulators:

All of our thermostats and thermostat inserts contain wax elements.

This is basically a temperature-controlled high-pressure hydraulic actuator motor with very high operating force between 30N and 2500N.

As a result, our bypass thermostats do not require an external auxiliary power source and, with minimal maintenance, are extremely reliable and robust!


Get contact information for ACS worldwide contacts, technical support, customer service, sales.

We will lend a sympathetic ear to all your requests.

As an independent company for engineering, marketing and service, ACS GmbH with headquarters in Gmund near Munich, Germany, is a specialist for thermostatically controlled liquid cooling circuits in the area of mobile and stationary hydraulics. Together with our partners, we work around the globe and use our decades’ long experience to make competitive, future-looking machine series and systems a reality. Our comprehensive product portfolio ranges from innovative thermal working elements to high-quality oil temperature regulators, thermoswitches and a variety of valves for air, gas and refrigeration compressors. One of our special features is our thermostatic controllers for the direct installation of a thermal bypass valve, eliminating the need for additional piping and seals.

High-quality thermo bypass valves – made in Germany

The high quality of our products and our customers’ satisfaction are our top priorities and the cornerstone of our global success in the area of cooling and regulation technology. All of our products, such as our thermo bypass valves, are the result of the latest technological findings and fulfil the highest requirements in terms of fluid mechanics, design and applications technology. In order to guarantee a longer life and high level of reliability, our industrial products are nearly 100% made in Germany. Flexible order processing and swift delivery times paired with technological expertise complete our company profile. Plus, we always offer our customers comprehensive assistance tailored to meet their needs.

Our product range: from bypass valves to coolant temperature regulators

Both the production and quality control of our components, as well as service and technical sales, are completed in Germany to allow us to best meet our own requirements and those of our customers. Our range of products for thermostatically controlled fluid circuits is wide and includes components such as oil temperature regulators for housing installations that offer direct and connection-free installation of a thermo bypass valve. By using a control valve or mixing valve, three sealing points can be reduced to just one. This eliminates time-consuming control edges and flow channel constructions in a unit’s housing. We also stock oil temperature regulators for pipeline construction, inserts for oil temperature control, coolant temperature controllers, as well as housing thermostats, thermoswitches and thermosensors.

How our ACS thermo bypass valves work

Our components are primarily used in oil and water glycol circuits of machinery, systems or aggregates. For more than two decades, we have focused on optimising temperature levels in liquid cooling circuits – all to achieve the greatest energy savings in a system. With the help of our components, oil is routed directly into the system during a cold start, without first having to pass through an oil cooler. Only after an optimum operating temperature has been reached do our thermal bypass valves allow the oil to pass through the radiator ­– without the help of an external auxiliary power source. With the assistance of the bypass valve or way valve, energy and fuel are saved, while wear and tear on many parts of the machine is extremely low.

Global Life Initiative: responsibility towards people and the environment

It is not only our demands for high product quality and customer satisfaction, but also the environment and our fellow humans that play a major role for us. As a conscientious company, we not only want to increase our own success, but to pass it on as well. It is for this reason that we launched the Global Life Initiative. Each year, we donate a part of our earnings to various projects that focus on the environment, humanity or education. Plus, we regularly ask our suppliers and customers to refrain from promotional giveaways or Christmas gifts, and instead put the money towards the initiative. Our donation recipients include Save the Rainforest, WWF World Wildlife Fund and World Vision.

ACS – a strong partner with a credit rating of 1

We earn trust in our work first and foremost through the high quality of our products, reliable working methods and punctual deliveries. We have also been able to demonstrate to our business partners, suppliers and customers that we too are a reliable partner without unfair financing or payment concepts. So we are proud to have been listed as one of the top business partners with a credit rating of 1 by the Hoppenstedt certification. This annual certification examines more than 4.5 million German companies in terms of their creditworthiness and rates them from 1 to 6. For more than 80 years, Hoppenstedt Kreditinformationen GmbH has been trusted with delivering reliable information and expert, independent research.

If you have questions about our innovative bypass valves or other components, don’t hesitate to contact us using our online contact form. You can also send us an email at info(at) or give us a call on +49 (0) 80 22 / 7064-0. Our team will be happy to help you.


Follow our latest achievements

  • Christmas greetings 2021

    Dear customers,
    Our goal is to infect our customers with our enthusiasm for our products. Your great interest in the past year shows us that we have succeeded. Thank you very much - for us this is an important incentive to offer you the best quality…

    Read more
  • Quality management successfully DIN ISO 9001:2018 certified

    We are pleased to announce that in April of this year, we successfully completed certification auditing by DNV:GL and are now DIN ISO 9001:2015 certified. Our stated goal is ensuring the consistent high quality of our products. With our quality…

    Read more
  • Hoppenstedt CreditCheck rates ACS as rank 1 company

    ACS belongs to the 4,4 % of german enterprises that have a Prime (AAA) status.

    Hoppenstedt is the leading publisher of financial information for businesses in Germany.
    With more than 20.000 customers, the group is among the leading suppliers of…

    Read more