Manufacturing subsystem

This chapter highlights and summarizes considerations dealing with expander subsystems, materials, manufacture, installation, component design, equipment maintenance and repair that might assist users in developing or evaluating turboexpander specifications. 

A system design is a product that is made up of a combination of devices and components. As described above the devices within a system are under the control of the designer and are designed specifically for the system. Components, on the other hand, are other devices and/or subsystems which are not made to the specification of the system designer. Usually these components are manufactured for a number of applications in various systems. Thus, the system design and the fabrication of the system are under the control of the system designer. The definition of a system infer complexity in design and operation. 

The FDA also use a systems approach when auditing device manufacturing sites. This breaks down the GMP requirements for devices into seven primary subsystems consisting of ... 

Complex manufacturing systems, such as an unbleached Kraft pulp plant (Fig. 9), are almost always characterized by some type of internal structure, composed of a number of interconnected subsystems with their own data collection and decisionmaking responsibilities. This raises a number of additional issues, not addressed in previous sections. For instance, if the learning methodology described in Section VI is applied to the digester module of a pulp plant (Fig. 9), it is possible for the final selected solution, to include ranges of desired values of sulfidity... 

The critical technology development areas are advanced materials, manufacturing techniques, and other advancements that will lower costs, increase durability, and improve reliability and performance for all fuel cell systems and applications. These activities need to address not only core fuel cell stack issues but also balance of plant (BOP) subsystems such as fuel processors hydrogen production, delivery, and storage power electronics sensors and controls air handling equipment and heat exchangers. Research and development areas include ... 

Different audit approaches may be applied depending on the intended purpose and scope of the audit. A top-down approach first evaluates the overall structure of the quality system and its subsystems. Selected subsystems may be chosen for review. Systems identified and developed by the FDA in a six-system inspection model for the inspection of drug manufacturers [15] include the following ... 

Auditing as described in QMS models is intended to assess the effectiveness of the overall quality system as designed and conformance to applicable standards. The overall quality system does not have to be covered in a single audit. Manufacturers may choose to employ a rolling audit approach in which specifically identified subsystems are chosen for evaluation in accordance with an approved audit schedule. Audit plans should be designed to effectively perform this assessment. 

Before undertaking either prospective or retrospective validation, the facilities, equipment, and subsystems used in connection with the manufacturing process must be qualified in conformance with cGMP requirements. 

Process demonstration formerly called process qualification, represents the actual studies or trials conducted to show that all systems, subsystems, or unit operations of a manufacturing process perform as intended that all critical process parameters operate within their assigned control limits and that such studies and trials, which form the basis of process capability design and testing, are verifiable and certifiable through appropriate documentation. 

Most firms today start by qualifying each subsystem. To qualify, of course, means to establish convincing evidence that something happens as intended, which matches the validation definition (in more explicit terms, however). Installation qualification may be defined as documented verification that all key aspects of the installation adhere to manufacturer s recommendations, appropriate codes, and approved design intentions. Operational qualification is documented verification that a system or subsystem performs as intended throughout all specified operating ranges. 

The committee believes that PEM electrolysis is subject to the same basic cost reduction drivers as those for fuel cells. Cost breakthroughs in (1) catalyst formulation and loading, (2) bipolar plate/flow field, (3) membrane expense and durability, (4) volume manufacturing of subsystems and modules by third parties, (5) overall design simplifications, and (6) scale economies (within limits) all promise to lower... 

For brown field applications, therefore, the extent to which the DCS hardware is to be replaced needs careful consideration, particularly at the I/O level. With many modem systems, it is possible to interface different types of FO subsystem to the controllers. The major manufacturers tend to support field instrumentation and I/O subsystems for extended periods of time, and therefore it will be worthwhile investigating how these can continue to be utilized within the new system. When contemplating the reuse of existing I/O and field devices consider the following ... 

By Security Council resolution 687 the IAEA was entrusted, inter alia, with the task of carrying out immediate on-site inspections of Iraq s nuclear capabilities based on Iraq s declarations and on the designation of additional locations by the Special Commission established pursuant to Paragraph 9(b) of that resolution. Pursuant to the resolution, Iraq was to submit to the Secretary General of the United Nations and to the Director General of the IAEA within 15 days of adoption of the resolution, a declaration of the locations, amounts and types of nuclear weapons, nuclear weapons-usable material and any subsystems or components and any research, development, support or manufacturing facilities related to nuclear weapons or nuclear weapons-usable material. 

The retrospective validation option is chosen for established products whose manufacturing processes are considered to be stable and when, on the basis of economic considerations and resource limitations, prospective qualification and validation experimentation cannot be justified. Prior to undertaking either prospective or retrospective validation, the facilities, equipment, and subsystems used in connection with the manufacturing process must be qualified in conformance with cGMP requirements. 

Importantly, hydrogen fuel cell vehicles provide special attractions to automakers. By eliminating most mechanical and hydraulic subsystems, they provide greater design flexibility and the potential for using fewer vehicle platforms and therefore more efficient manufacturing approaches. As a result, the automotive industry, or at least an important slice of it, sees fuel cells as its inevitable and desired future. As noted by Jim Boyd in Chapter 10, automaker support was not evident in other movements to promote alternative fuels. 

An economic analysis for the hydrogen refueling station is being performed. Based on information from the literature, the cost of each subsystem of the refueling station was expressed as a function of the quantity manufactured and the hydrogen capacity. Preliminary estimates were made for cost of H2. 

Table 2 shows the information available in the literature for capital costs of the reformer (excluding the PSA), hydrogen compressor, storage tanks and dispenser island scaled to a hydrogen capacity of 10,000 std m per day (900 kg of H2 per day or 1249 kW of H2 on a EHV basis). Scaling factors were applied to determine the costs of the units as the manufactured quantities increase. The relationships between hydrogen capacity and subsystem capital cost are also shown in Table 2. 

Table 2. Capital cost for refueling station subsystems as a function of the manufactured quantities. The delivered hydrogen capacity is 67 kg/day.

At the preclinical product phase, critical and noncritical classification of process input parameters should be initiated [32]. Critical components of facility subsystem validation need to be essentially complete before phase I product manufacture [15]. For phase I, it is necessary to validate aspects of the process related to product safety (e.g., sterility, mycoplasma, viral clearance, impurity removal, and stability) [14]. Abbreviated viral clearance studies for model viruses/retroviruses and impurity clearance studies for host cell DNA often are acceptable, resulting in fewer downstream steps validated at this product stage [3, 5]. If viral clearance results are available in sufficient time, the results can be applied to developing the phase I process steps. All assays do not have to be validated at this stage, but some (especially product-specific ones) should be at least qualified [14]. 

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