Burkert Multi-Port Valve Interfaces Meet Stiff Requirements for Space Saving, Sterilisation & Cleaning in New Life Science Plant

The ROBOLUX units meet all the demanding specifications for process valves and interfaces laid down for the new LIFE plant. They enable compact and complex valve interfaces to be achieved in the most restricted installation space, and have practically no dead flow zone, which makes both cleaning and sterilisation much easier and faster, and also enables quicker changeover for the manufacture of different product types.

B.Braun’s LIFE Nutrition plant, situated at the company headquarters in the North German city of Melsungen, is one of the world's most modern production sites for innovative nutrition solutions. Solutions for clinical nutrition, such as amino acid solutions, carbohydrate solutions and fat emulsions are manufactured and packaged in two production lines at the new manufacturing facility, with its integrated laboratory. After more than five years of planning and construction, and an extensive test phase, the plant is scheduled to start full-time production during 2012.

The special challenges in the planning of LIFE Nutrition included the requirement that the new plant be housed in a building that is spatially identical to that of B. Braun’s older LIFE plant. Despite this spatial constraint, the new production facilities needed to be significantly more efficient, flexible – and space saving. During the search for innovative, space-saving solutions for the complex valve interfaces required for production at the LIFE Nutrition plant, B. Braun’s consulting engineer, Chemgineering, contacted a number of suppliers, fluid technology specialist, Burkert, among them. With its multi-port ROBOLUX valve, Burkert has a patented solution in its portfolio for achieving very complex and compact valve interfaces with a low internal volume. Following consultations with Chemgineering on the process specifications, Burkert developed -within a few weeks - models for the first, especially- complex valve interfaces. These models were professionally visualised and presented with the help of modern 3-D PDF files.

The advantages of a Robolux multi-port system in comparison with conventional single-layer valve interfaces and ring systems were literally evident at first glance,” said Alexander Equit, National Key Account Manager for Pharma, Biotech and Fine Chemistry at Burkert.

“The special feature of the patented Robolux valve design is that two independent process switching functions can be achieved with one membrane,” said Equit. “This reduces installation requirements, eliminates T-adapters and minimises the overall number of valves and membranes required. The multi-port membrane valves were designed for high-purity installations and make it possible to design complex systems that are considerably more compact. Due to this technology, even a 1O-port valve interface requires very little installation space, has a minimal internal volume and practically no dead flow zone. The lower inner volume offers several advantages: In addition to improved flow and evacuation properties, both cleaning and changeover of the interfaces for the manufacture of other products is easier and faster.”

The valve interface concept presented jointly by Burkert and Chemgineering convinced B. Braun. On the basis of the Robolux valve interface, a new fluidics scheme was developed and modern multi-port Robolux systems were included in the provisional plans for the new LIFE plant.
“The compact design, as well as the possibility to connect Robolux with standard systems, has resulted in valve interfaces that meet the technical and practical needs of the LIFE plant - such as maintenance and cleaning, as well as flexibility in different operational modes. These system solutions are unparalleled, prompting optimisations that standard solutions can only offer with difficulty, or to a limited extent,” commented S. Reinhardt a spokesman for C. Dostal, the organisation that operates both B.Braun’s original LIFE Infusion and new LIFE Nutrition plants.

The Robolux interfaces can be cleaned optimally and very effectively due to directional flow. This systematically prevents the typical disadvantages of ring systems – which have especially large inner volumes and undefined flow, factors that complicate cleaning. The result of this design feature is that, in steam sterilisation, a Robolux valve interface reaches the required sterilisation temperature in about half the time. However, even with this, and the many other advantages provided by Robolux, the final decision to use the valve technology was still pending, because a number of hurdles still remained to be overcome. The requirements and standards for use in Life Science systems are extremely high, not only at B. Braun, and are continuously reviewed through audits,” explained Alexander Equit.

The way these requirements and standards impacted upon Burkert, was through a prerequisite to demonstrate that the complex Robolux valve interfaces could be delivered with a surface quality, as defined by the Basler Standard BN94. Here, a solution was provided by Burkert group company, BBS-Systems AG in Wil, Switzerland, which developed a system for reliable electro- polishing of the Robolux systems. This involves the removal of 30µm of metal from the media contact surface with a special electrolyte, under the effect of DC current. The material is removed without mechanical, thermal and chemical influences. As a result, the surface becomes smooth and shiny in the micro range; possible damaged outer layers are removed, and the properties of the pure stainless steel can be utilised. For reliable electropolishing of the complex interior of a 1O-port system in all areas, the standard process had to be modified, somewhat, and adapted to the special requirements of these solutions.

Subsequent to the development of the electro-polishing system, audits were carried out to validate not only the electro- polishing process itself, but also the black- white separation in Burkert's production plants of products that are intended for the Biotech sector. This separation means that all components manufactured from stainless steel may come into contact only with stainless steel, to avoid contamination and rust film. This is also true for the bodies of fittings used in conjunction with the Robolux valves. These are produced on special production lines, where only stainless steel is used.

Once the ability to deliver surface quality to the required standard had been demonstrated, the focus in the supply of the Robolux multi-port valve interfaces turned to actual production requirements: those of quality and compliance to defined standards, which are checked regularly in unannounced Factory Acceptance Tests.

As a key contributor to the FAT, Burkert conducted riboflavin tests on the most complex of the Robolux valve interfaces, using the company’s own proprietary test rig. In compliance with the VDMA directive, the inside of the valve interfaces is fully soaked using an atomiser with a test solution containing riboflavin that fluoresces when exposed to UV light. With the help of these tests, the flow properties and cleanability of fluidic systems and valve interfaces can be determined with one hundred percent reliability.

In addition to their primary objective, the riboflavin tests brought added benefits, in that the results of the tests can be used for optimising cleaning processes, in respect of cleaning cycles, cleaning time and the quantity of cleaning agents required. Moreover, the design of complex valve interfaces in a test phase can be evaluated and optimised by the use of riboflavin tests. This is a unique offering from Burkert, because the company is currently the only manufacturer of fittings and valve interfaces in the world that owns and operates a riboflavin test rig.

After the approvals process was completed Burkert was awarded the contract not only for the Robolux valve interfaces, but also all the process fittings for the LIFE