Robovalve Eases Cleaning, Validation for GMP Processes

Steve Aldrich, VNE Corp.

Contents
Summary
Robovalve Design
Easier Cleaning, Validation
Real-Life Example

Summary (Back to Top)
For years it has been recognized that diaphragm valves can be cleaned and sterilized in place without need for repeated dismantling. Thus, they have found wide acceptance in pharmaceutical, biopharmaceutical, semi-conductor, food, beverage and any other processes where sterility and ease of cleaning are an absolute requirement. The Robovalve is the next logical development of the diaphragm valve. SE multi-way, multi-port valves manufactured in Sweden and distributed by VNE Corp. (Janesville, WI) give exceptional efficiency and flexibility of valve arrangement, function and design. The minimum space requirement yields a compact design and the absolute minimum of dead volume.

Recent years have seen a rapid acceleration in the scale of operation and required efficiency of liquid handling in manufacturing processes. This trend coincides with increased requirement for sterility, ease of cleaning, and ease of validation of hardware, systems and processes. Tightening regulations along with necessity for elimination of risk from cross contamination have required new concepts in valve design; valves that eliminate dead volumes within the systems and assure that all surfaces are reached by clean in place (CIP) solutions. The increased requirement for various manifold designs to be placed in limited space and thus yielding no or, at least, minimal dead volume have required new concepts in valve design.

A uniquely designed multi-port, multi-way (Robovalve) valve designed in Sweden and distributed in the United States by VNE Corp. had met these requirements head on.

Robovalve Design (Back to Top)
The Robovalve design combines several components within one valve body. Two valves are mounted under one diaphragm, each independently actuated. This is made possible by having two parallel weirs opening into a central chamber. This chamber may have a single or double outlet port. Thus, a series of valves coupled together will form a continuous "straight through" tube with no hold-up of CIP fluid.

Valves must be compatible with and suitable for the materials being processed. They must withstand repeated cleaning with harsh and aggressive CIP chemicals. Internal surfaces require high quality finish (low Ra) and, as stated, the valve body must ensure liquid contact with all surfaces exposed to product. However, designs of many multi-way, multi-port valves do not lend themselves to easy cleaning and thus, validation of cleanliness. In many, one finds screw threads, springs, etc., in contact with process fluid. In the same way,, multi-way ball valves are not hygienic due to the presence of stem seals, sealing rings with voids, and residue on the ball itself.

Easier Cleaning, Validation (Back to Top)
Because of the problems mentioned above, biopharmaceutical industry, in their GPM manufacturing facilities and, increasingly, in the pre-clinical and development stages is turning to the newer designs of diaphragm valves, so that the product and process fluids are isolated from the newer designs of diaphragm valves, so that the product and process fluids are isolated from the mechanical aspects and potential contamination. These designs eliminate dead volume and provide a safe and sanitary method of process, CIP and control of flow. Validation is therefore made much easier.

Valve diaphragms must be capable of withstanding repeated exposure to severe cleaning and sterilizing agents as well as tens of thousand of actuations. Suitable materials have been developed within the last decade that have contributed to the success of the multi-way, multi-port diaphragm valve. Peroxide cured EDPM, platinum cured silicon, second generation PTFE, fluorelastomers and perfluorelastomers are strong, flexible and chemically resistant. Diaphragms from these materials are well suited to and compatible with biopharmaceutical and allied applications. Robovalve supplies any one of these materials bases on the customer's requirement. All materials have been tested under USP 23 requirements and are certified according to FDA regulations CFR 177.2600 for contact with parental drugs plus other pharmaceuticals and food products.

Pipe branch sections are a very difficult element in fluid piping processes, particularly when cross-contamination must be avoided. At these branches one will find holdup or dead zones. It is extremely difficult to assure complete removal of residual contaminants such as minute particles and bacteria which remain upswept in these "dead zones". The design of the Robovalve was done after much study of this dead zone phenomenon. The resultant design succeeds in improving displacement between two types of fluid by 15X compared to most other valves presently being used. The result of this faster flow shift is savings in cleaning cost.

Real-Life Example (Back to Top)
One example of such savings due to faster shift time is a plant where a total of 60 hours was required per batch, including 12 hours of actual treatment processing and 48 hours of post-cleaning. By introducing multi-way, multi-port valving with faster shift time the post-cleaning time was reduced to 30 minutes with the total cleaning time being 12.5 hours. Thus, an improvement off more than 300% in production efficiency was seen in this particular application.

The Robovalve provided through VNE and selected distributors is not a standard unit modified for special application but rather, as mentioned above, it is a new, yet proven, design that came after much study of dead zone phenomena and the requirments of the industry. All eight versions of the stainless steel valve and the two versions of the plastic valve in what ever line size from 3/8" to 2", manual or pneumatic, have a design specifically manufactured to yield full sanitary and aseptic operation with a minimum of dead volume and the maximum in efficiency. The unique, two weir double diaphragm operating principle presents particle and simple solutions to complex fluid handling problems. The internal finish of <0.5 Ra passivated or electropolished is unsurpassed.

For more information: Glenn Stoll, Sales Manager, VNE Corp., 1149 Barberry Dr., PO Box 1698, Janesville, WI 53545. Tel: 608-756-4930. Fax: 608-756-3643.