618 Fermentation and Biochemical Engineering Handbook connections are not recommended and should be replaced with soldered passivated or sanitary clamp connections. The transport ofliquid streams can be accomplished using either pressure or pumps. For pressure transfer with organic solvent, nitrogen is preferred due to its noncombustible properties however, appropriate safety precautions need to be considered in the system design. A flow diagram illustrating solution preparation is shown in Fig. 1 The location of the sterile filter traditionally has been on the non-sterile side primarily for ease of changing and to minimize contamination of sterile area if leakages occur. However, new designs have the filter on the sterile side NONSTERILE AREA STERILE AREA ( CLASS100,000) (CLASS 100 PRE-FILTER STERILE FILTER CRYSTALLIZER DISSOLUTION Figure 1. Bulk solution preparation 30 ISOLATION OF STERILE BULK PRODUCT 3.1 General Considerations All equipment should be easy to clean and steam sterilizable and have a sanitary finish. If the facility is not dedicated to one product, computer automated"recipes"provide the greatest control and flexibility for process ing. The overall operation must be designed so as to minimize the personnel required to operate the equipment and thus minimize the exposure of product61 8 Fermentation and Biochemical Engineering Handbook connections are not recommended and should be replaced with soldered, passivated or sanitary clamp connections. The transport of liquid streams can be accomplished using either pressure or pumps. For pressure transfer with organic solvent, nitrogen is preferred due to its noncombustible properties; however, appropriate safety precautions need to be considered in the system design. A flow diagram illustrating solution preparation is shown in Fig. 1. The location of the sterile filter traditionally has been on the non-sterile side primarily for ease of changing and to minimize contamination of sterile area if leakages occur. However, new designs have the filter on the sterile side. NONSTERILE AREA STERILE AREA (CLASS 100,000) Figure 1. Bulk solution preparation 3.0 ISOLATION OF STERILE BULK PRODUCT 3.1 General Considerations All equipment should be easy to clean and steam sterilizable and have a sanitary finish. If the facility is not dedicated to one product, computer automated “recipes” provide the greatest control and flexibility for process￾ing. The overall operation must be designed so as to minimize the personnel required to operate the equipment and thus minimize the exposure of product