In many cases, a rotary actuator cannot be mounted directly onto the valve due to a different square or octagonal shape. We offer the appropriate square or octagonal reducers for this purpose.
Adaptors - RHE - RHX | Eurotec
Eurotec RHE / RHX Adaptors
Eurotec RHE / RHX adaptors are mechanical coupling devices for quarter-turn actuators and valves. They are used when the actuator output and valve stem have different geometries or dimensions, such as square, double square, or octagonal profiles.
Types and Applications
- RHE: Square-to-square adaptors for matching different square drive sizes.
- RHX: Adaptors for internal double square or octagonal actuator outputs to square valve stems.
- Used with ball valves, butterfly valves, and plug valves.
- Compatible with pneumatic or electric rotary actuators.
The adaptors transmit torque from the actuator to the valve stem without introducing side loads or misalignment.
Selection Criteria
Selection of RHE or RHX depends on:
- Actuator output dimension
- Valve stem profile
- Required operating torque
- Coupling height with mounting bracket
- ISO 5211 mounting kit compatibility
- Square/double square tolerances
Incorrect adaptor selection can cause mechanical play, increased operating torque, stem packing wear, or incomplete valve closure.
Role in Valve-Actuator Assemblies
RHE / RHX adaptors are not exposed to process media. They are part of the mechanical mounting kit, together with brackets, bolts, and couplings. Proper alignment is critical, especially for valves operating under high differential pressure or frequent cycling.
Certifications
Eurotec references DIN EN ISO 9001:2015 and ISO/IEC 80079-34 for component manufacturing. Ex suitability applies to the complete assembly, not the adaptor alone.
FAQ
When are RHE / RHX adaptors used?
When the actuator cannot be directly coupled to the valve stem due to differing drive shapes or sizes.
What is checked during maintenance?
Mechanical play, edge wear, corrosion, fit on the square, mounting kit tightness, and changes in operating torque.
Datasheet and documents
Description
Certificates
DIN EN ISO 9001:2015
EUROTEC Antriebszubehör GmbH is a company certified according to ISO 9001-2015. The certification body of TÜV SÜD Management Service GmbH certifies that our company is certified for system components for the automation of industrial valves in the areas of
- Development
- Production
- Distribution
has introduced and successfully applies a quality management system
ISO/IEC 80079-34 (ATEX-QM)
EUROTEC Antriebszubehör GmbH is a certified manufacturer of devices and protective systems for intended use in potentially explosive atmospheres in accordance with Directive 2014/34/EU and the quality management standard ISO IEC 80079-34. We are audited annually and attach great importance to safe processes for the manufacture of absolutely safe and reliable products.
You can download the following certificates here:
For further questions about explosion protection, ask our experts
EU declaration of conformity
With our products we meet the requirements of the Machinery Directive 2006/42/EC as well as the Low Voltage Directive 2014/35/EU and the EMC Directive 2014/30/EU.
You can download the EU declarations of conformity for the standard range here:
The ATEX declarations of conformity for the explosion-proof products can be found on the product pages directly for the respective limit switch box series.
SIL
For use in safety-relevant systems and processes, we have carried out an FMEDA for our limit switch boxes and solenoid valves in collaboration with exida and classified our products into the corresponding SIL levels. Our products meet the criteria from SIL 1 to SIL 3.
You can download the SIL declarations of conformity here:
For more information, ask our experts.
EAC-TR (Russia)
Our limit switch boxes are also certified according to the Russian standard EAC TR CU 004 and TR CU 012. You can download the certificate for the explosion-proof area here:
EAC approval for limit switch boxes (Ex-protected)
CCC (China)
Our limit switch boxes are also certified according to the Chinese standard CCC, CNCA-C23-01:2019. You can download the certificates here:
UKCA (England)
Our products for explosion-proof areas are also certified according to the British standard UKCA, UKSI 2016:1107.
ROHS
EUROTEC Antriebszubehör GmbH is aware of its responsibility towards the environment and people.
We attach great importance to the greatest possible transparency in the supply chain and provide all information to the best of our knowledge and belief.
REACH
EUROTEC Antriebszubehör GmbH is aware of its responsibility towards the environment and people.
We attach great importance to the greatest possible transparency in the supply chain and provide all information to the best of our knowledge and belief.
Regulation EC 1907/2006 (REACH)
Tap to zoom
