Subscribe to our monthly newsletter.

Share this item

Hagen-based manufacturer EBRO ARMATUREN boasts unparalleled expertise in developing liners for industrial valves. As well as focusing on the development of standard liners from elastomers, its Experimental Development department also comes up with solutions that meet all manner of customer requirements – tailored to their specific area of application.

An essential component with wide-ranging tasks

The liner is the critical component of any shut-off or control valve. When the valve is closed, it ensures reliable sealing; when it is open, it guarantees an unobstructed flow for the medium and perfectly sealed shaft and flange connections. In the process, elastic liners are exposed to a wide range of mechanical, chemical and thermal loads. These include abrasive and aggressive media as well as extreme temperatures and pressures, not to mention the strain put on them by the deformation that occurs whenever they are opened or closed. Thorsten Hardt, Head of Product Management, comments: “So that we can guarantee our customers the best-possible solution at all times, we don’t just offer standard solutions. Our Engineering Design and Experimental Development departments also develop liners for our customers that have been specifically optimised to suit the media they’re using and the properties they’re looking for. As well as having a level of expertise in this area that’s unique in the industry, EBRO also possesses the resources and testing facilities required to ensure a high-quality, long-lasting solution.” While Engineering Design deals with the design of the liners, Experimental Development develops the necessary elastomers and plastics in collaboration with the suppliers.

Experimental Development

Experimental Development comes into play whenever standard solutions are reaching their limits and it is essential that a liner material is precisely tailored to the customer’s specific application and medium without accepting any compromises. Changes to licenses and certificates also often require existing liner materials to be modified.
There is a huge range of potential applications. To be able to identify liner wear in food production immediately, for example, a particular shade of colour might be required. Extreme temperatures, e.g. if the valve is to be used for hydraulic oil at an ambient temperature of
-50°C, might be another reason to call in Experimental Development. To guarantee reliable sealing, the liner has to retain a certain degree of elasticity at these ultra-low temperatures, while also being resistant to the medium in use. Another situation may call for the liner’s service life to be extended in use with bulk goods in order to lengthen maintenance cycles and reduce costs in the long term. Additionally, interactions between the ingredients contained in the customer’s medium, e.g. in the food or chemicals industry, can also necessitate a tailored development.

It’s all in the mix

For its liners, EBRO uses various types of base materials, ranging from chlorosulphonated polyethylene (CSM) and polymers such as ethylene propylene diene monomer (EPDM) through to silicone rubber (VMQ) and many more. Their properties make them the ideal foundation for further development work. Modifying and tweaking the ingredients then serves to magnify the properties being sought in the specific case and/or reduce any undesirable ones.
Working closely with the customer, suppliers of many years standing and other development partners is vital in this development process. Often, therefore, the customer will get EBRO closely involved with projects for new installations right from the planning stage.
EBRO’s development partners include high-profile institutions such as the Institute for Plastics Processing (IKV) at RWTH Aachen University, the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), the German Institute of Rubber Technology (DIK) and many others. This close collaboration from the development phase onwards lays the foundations for problem-free certification further down the line.

Painstaking development work for maximum quality

The development process itself starts with the drafting of a set of specifications for the liner at the customer’s end. The relevant requirements are compared with existing materials and the current state of the art in a target/actual performance analysis, and the feasibility of the desired properties is verified both in house and externally. The requirements are then passed on to the supplier, who fine-tunes the mix together with EBRO. These suppliers have been working with EBRO in this field for many years and have an exceptionally high level of expertise. Extensive tests are carried out with the material in this phase, both at the supplier’s premises and at EBRO, in order to achieve maximum quality and test the required characteristics. For this purpose, EBRO operates a test centre that is probably the only one of its kind in the industry. It can handle material tests ranging from cross-linking curves, IR spectroscopy, light microscopy and various dimensional measurements through to density, hardness, various tensile tests, tear resistance, stress relaxation, compression set, swelling and ageing. A large number of tests are also carried out on the valve once it has been assembled, allowing the information provided by suppliers to be checked in house and corrected if necessary. In this way, EBRO makes sure that the necessary requirements are met for licensing in the respective area of application, such as FDA/EC for foodstuffs, DVGW Wasser, WRAS, NSF, ACS and KIWA for drinking water applications, and many more besides.

An extensive range

Says Thorsten Hardt: “We want to supply the customer with a valve tailored to their individual requirements if that’s what they need. As well as its own development team, EBRO also has one of the most extensive product ranges in the industry in order to do just that. This encompasses valve bodies, liners and all manner of different actuators as well as control systems such as our SBU IO-Link. So we’re always in a position to offer our customers a perfectly aligned end-to-end solution.”