Selection of design criteria and selection of components will be determined by (1) cost, (2) the need for freedom of manual intervention for connections or cleaning, (3) flexibility requirements, (4) control needs and (5) the requirement to verify integrity of each and every product and CIP solutions stream, the need for sterility which requires SIP after CIP.  Though Portable Tanks and Flexible Hoses maximize flexibility, the highly automated CIPable process will be based on fixed tanks connected by permanently welded piping with flow control accomplished by air-operated valves and U-Bend Transfer Panels in various combinations 

CIP Cleanable Air-Operated Valves 

* Whereas manual "make-break" connections may be preferred or required  between solution containing piping and vessels and product containing piping and vessels, the flow within the processing system may be controlled by valves.  

        -       These valves may be manually operated and manually cleaned, or 

        -       ... they may be automatically controlled with provisions being made in the cleaning program to properly "pulse" or "sequence" valves to assure proper cleaning of all internal parts and interconnecting piping. 

* The air-operated Compression valve shown at the right is  representative of automatically operated valves most widely used in dairy and food processes and, to a lesser degree in pharmaceutical solutions processes.  This valve is equipped with an air-to-raise actuator and is thus normally closed. The actuator is field convertible to air-to-lower operation to produce a normally-open valve. 

        -       The standard elastomer on the plug assembly, stem O-ring and body gasket is Buna N. Other elastomers such as Viton, Steam Resistant Viton, EPDM and Butyl are available. These would be used on higher temperature applications or where steam sterilizing is desired. 

        -       These valves are of the open-yoke design, fully sanitary, and CIP cleanable if properly installed to assure drainage. The valve has a short stroke and expanded body to give a "full-flow" area. 

* Compression valves most widely used in dairy and food processes  are generally of non-aseptic design. Other versions of this valve are available as tangential tank outlet valves,  kettle valves, and throttling valves. Valve position indicators are available and valve positioners may be incorporated to provide a stabilizing action for exacting control of flow, temperature or pressure. Three-port "divert" valves are available in addition to the tee and cross type valves. Note that when the stem of a 3-port valve moves from one position to the other that all ports are connected for a brief period of time, causing (a) first mixing and then (b) a resultant dead end in the previous path while the current path is in use. Three-port divert valves must be installed with the common port facing down or with the entire valve in a vertical position to insure compliance with the requirement for the piping system to be "drainable". 

* Several diaphragm valves are shown in the photo below.  Such valves are available with clamp, weld  and NPT ends. They eliminate the concern about cleaning the valve stem O-ring. However,  to design a "drainable" piping system, valves in a horizontal run must be inclined at an angle.  Diaphragm valves are available in a "Zero Dead-Leg" version and with supplemental "Take-Off" ports.  An alternative Radial Diaphragm  valve combines the cleanability of the diaphragm valve with the arrangement capability of the compression valve; i.e., vertical mounting for drainability and reduced space requirement. 

Automated Process Piping Design with Compression Valves 

Valve Manifold Asssemblies (Valve groups or VG's) are a commonly used means of applying air-operated valves in a CIP cleanable piping system in dairy, brewing, and many food processes. The isometric drawing Fill/Discharge Valve Groups and Associated CIPS/R Piping depicts a means of filling, emptying and cleaning three tanks via a low-level valve group and a product transfer pump. 

U-Bend Transfer Panels 

U-bend transfer panels have been combined with highly-automated "sub systems" in developing designs, installing, and placing into operation a number of successful parenteral solution systems. This approach provides a maximum flexibility for the production function, yet makes it possible to assure controlled sanitation through mechanical/chemical cleaning and further guarantees the integrity of all individual product and cleaning and/or sterilizing flow paths. Such transfer panels are the result of continued modification and development of the component commonly referred to as a "flow-verter" or "cleaning hook-up station" used in the past primarily to control CIP solution distribution. 

Four variations of small U-Bend Transfer Panels may be examined at esc4cip.com. With exception of the two-port arrangement  they  are based on some variation on the 120 degree triangle or the more complex hexagon. CHS-2, -4 and -6 on U-Bend Transfer Panels in a Pharmaceutical Process are based on the 4-port diamond arrangement in the vertical format and TP3 on this same schematic is the conventional 4-port arrangement rotated 30 degrees  to place the non-connecting ports at opposite ends on the horizontal axis. The basic 6-port hexagon is widely used in many expanded forms to connect several primary ports to a multitude of others with a common length U-Bend.   The dairy transfer panel at the tight is based on headers connected to a series of ports leading to tanks. 
 
Elimination of Dead Ends - The utilization of headers in transfer panels as shown at the right requires special emphasis on the elimination of any dead ends. A branch of a tee (for example, the port from the header to the skin of the transfer panel) must be limited to approximately 1-1/2 pipe diameters to allow recirculation cleaning at normal velocities. Headers may be of double-tube construction or loop-type design.  Additional information can be found at esc4cip.com. 

Proximity Sensors - The use of manually-positioned U-bends for establishing processing, Clean-In-Place and Steam-In-Place connections in a highly automated system requires some means of verifying the integrity of the required flow paths. This has been accomplished in practice by installing permanent magnets in stainless steel enclosures welded to the center of the U-bend connection. Proximity switches located behind the skin of the transfer panel may then be used to detect the presence or absence of a U-bend between any selected pair of ports. The computer or programmable controller database is developed to include the "allowed" or "required" connection for every established flow path necessary for processing, cleaning or sterilizing procedures. 

Mixproof Valves 

Air-operated CIP-cleanable compression-type valves have been applied to automate dairy processes since the early 1960's. However, FDA regulations and 3-A Standards have never permitted a valve of any type to be used to separate a product containing vessel or line from a vessel or line containing cleaning solutions, requiring instead a design which provides "make-break" connections for such isolation purposes. The proper and effective cleaning of an air-operated valve of any type requires that solution pass through the valve during the CIP operation and this in turn requires that the extensions of the supply lines and discharge lines from valve groups as shown on Figures III-7 must be connected for the line CIP operation which generally occurs at the end of each day or at least once during each 24-hour p 

More than two decades ago, several European manufacturers introduced the concept of mix-proof valves via the design and application of a single valve which provides the normal function of the well known "double block-and-bleed" concept in reduced space, at lower cost, and   in a fully CIP cleanable design. Mix-proof valves have been used extensively in the brewing industry and more recently in a variety of non-dairy food processes. They have also been incorporated in several recent designs for pharmaceutical applications. The photograph at the right is of a mixproof valve recently introduced in the USA and designed to FDA and 3-A standards to include a full size leak port.  The subsequent links provide examples of a minimal application and a full application of mixproof valves in designing a CIPable pharmaceutical process. 

Mixproof Valves as a Replacement for U-Bend Transfer Panels 

Mixproof Valves for Maximum Automation 

Integration of Reactor Leg Piping in the Tank CIP Circuit 

The interconnecting piping associated with each of the reactors of a fermentation train requires cleaning     and steaming to the same degree as the vessel. The most effective manner to accomplish this is to clean all piping from external CIPS connections to the reactor  when cleaning the reactor, thus washing through all valves and nozzles.  Verification of Flow in Parallel Paths 
is a problem which may be encountered in any complex multi-path CIP circuit, and a Click on the above link will describe a procedure which has been used successfully in several different manners. 

Summary 

This section has been developed using line drawings and photographs of "real world" projects, accumulated over a period of nearly 40 years.  The intent is not to provide solutions to all design problems, but rather illustrate how the multiude of available components and design concepts may be combined to meet the needs of each individual project. 

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