这段话如何理解呢？？？？

beiwei5du

SD-2.4.3 Drainability
SD-2.4.3.1 General. For sterility and cleaning,gravity is an effective way to facilitate drainage. To achieve gravity drainage, lines should be pitched to designated points at a specific slope. Refer to Nonmandatory Appendix C for suggested method of slope measurement. For gravity-drained piping/tubing systems, the owner/user may define the system slope in accordance with one of the designations listed in Table SD-2.4.3.1-1. Gravity-drained piping/tubing systems shall have a continuous pitch that is equal to or greater than the slope designation. Line sections up to 10 in. (25 cm) in length (or longer with advance approval of owner/user) that are level or have a positive slope less than the slope designation are acceptable if the section is fitting-bound.
选自《ASME 2014》


请问一下该指南中有对于重力排净管道长度达到10英寸（即25厘米）的管线，如果由于设备限制而设计成水平或者比制定斜度小的情况是可以接受的。为什么有这样的规定呢？？？10英寸是怎么制定出来的？？是基于什么依据选取的这个值的呢？？？
谢谢！

雪锋

关注中

伤不起520

又是英语呀！！！！！！

凤尾竹瑄

嗨，你们英语水平真可以