The process continues with an evaluation of the steam system requirements (generation) that includes: the selection of the type of generation system that would satisfy each category, which would include:
? The types of generation systems available. (If both pyrogen free clean steam and clean steam
without endotoxin limits is required, the practicality and economy of producing only the
higher grade should be raised.)
? The source of utility steam or electrical power (The plant steam requirement for clean steam
as well as utility steam and the option of electric powered steam generators should be considered.)
? The type and number of systems required based on feedback from the \evaluation.
? The condensate sampling needs.
? Safety considerations
使用不同的方法产生制药用蒸气。对每个应用必须选择大多数适当方法。（参看制药用蒸气纯度决策树，7.6部分。）用蒸气系统要求（产生）的评估来继续过程，该系统要求包括：产生系统类型的选择将要满足如下每个种类：
? 可用产生系统类型（如果无热原清洁蒸气和无内毒素限制的清洁蒸气都需要，那么应该
提高只产生较高级别蒸气的实用性和经济性） ? 公用蒸气的电源或电力动力（与公用蒸气一样的清洁蒸气的车间蒸气要求和电力蒸气发生器的选项都应该一起考虑。）
? 系统的类型和数量要求以“分配系统”评估的反馈为根据 ? 冷凝液抽样需要 ? 安全性考虑
7.5.3 Use Point Criteria 7.5.3 用点标准
The third step defines the specific delivery requirement ranges for clean steam at the point of use including:
? Utilization, which is determined from each overall system peak demand(s), average demand, and the relationships between peak demand time periods and their flow rates. ? Pressures and flow levels
? Use periods and histogram analysis, if available ? Quality
? Purity
第三步为在使用点的清洁蒸气规定详细交付要求范围包括：
? 使用是由每个完整系统的高峰需求、平均需求和高峰需求时间周期与其流速关系决定 ? 压力和流量水平
? 使用周期和柱状图分析，如果可得到 ? 质量 ? 纯度
7.5.4 Distribution System 7.5.4 分配系统
The fourth step includes the distribution system evaluation, which includes; ? Condensate, non-condensable and moisture removal ? Pipe size and Insulation requirements including:
? Materials of construction, sanitary design requirements and surface finish
? Physical location of each use point ? Heat and temperature losses ? Natural drainage
第四步包括如下分配系统评价： ? 冷凝液，非凝液和湿度去除 ? 管道型号和绝缘体要求，包括：
? 构造材料，清洁设计要求和表面抛光度 ? 每个使用点的物理位置 ? 热量和温度损失 ? 自然排水
Note: Since the steam quality will decline, due to heat losses, with time, the efficiency of the insulation and the length of the distribution system, the quality at the use point will not be expected to reflect the generation quality level.
注意：由于热损失，随着时间、绝缘体效能和分配系统的长度，蒸气质量将下降，因此在使用点的蒸气质量将不能反映产生质量水平。
7.5.5 Re-evaluation of system boundaries and constraints 7.5.5 系统边界和限制的再评价
These sequential steps are repeated and re-evaluated as information in the design process iterates, and further criteria about the overall system boundaries are identified. (See Figure 7-3.)
In operations with a requirement for only one grade of steam, the steam system is designed to meet the most stringent requirements of the most demanding product or process. With more than one purity grade of steam, products and processes are often categorized and fed by the most appropriate system. The number of types of steam generated is most often a function of the volume of steam consumed and variation of purity required.
重复和再评价这些连续步骤作为信息设计过程的重复并且确认关于整个系统边界进一步的标准（参看图表7-3）。一种设备的操作中只有一种蒸气等级，蒸气系统的设计要符合大多数高要求产品或工艺的大多数严格要求。伴随超过一种蒸气纯度等级，常常把产品和工艺分类并且提供大多数适合的系统。产生蒸气类型的数量大多数经常是消耗蒸气体积和所需纯度变化的作用。
7.6 PHARMACEUTICAL STEAM PURITY DECISION TREE 7.6 制药用蒸气纯度决策树
Figure 7-2 Pharmaceutical Steam Purity Decision Tree 图表 7-2 制药用蒸气纯度决策树 Steam for Humidification Is Product Exposed to Air? Steam for Process or Sterilization START Steam for Energy Transfer YES YES Does Steam Contact the Product? NO NO CLEAN STEAM Could Corrosion Inhibitors or Pyrogens Compromise Product? NO Utility Steam Appropriately Filtered Utility Steam YES The figure above provides \requirements for most pharmaceutical steam applications. Purity requirements for steam used in pharmaceutical manufacturing and
product development are driven by the product characteristics, manufacturing process and the intended use of the product. Specific product and process characteristics may
dictate that more or less stringent criteria is appropriate.
是 否 否 否 是否腐蚀抑制剂或 热原危及产品？ 产品是否暴露在空气中？ 起始 增湿 蒸汽 工艺或灭菌 蒸汽 能量转换 蒸汽 是 是 蒸汽是否 接触产品？ 适当滤过的 蒸汽 公用蒸汽 清洁蒸汽 上面的图表为大多数制药用蒸汽应用提供“基线” 要求。用于制药生产和产品研发的蒸汽纯度要求由产品的特性、生产工艺和预期用途决定。特殊产品和工艺特性可能要求更多或更少的严格标准是适合的。
