How to Destroy a Vacuum System

Carpenters have a saying measure twice, cut once. This saying implies that any extra time spent in preparation saves time and materials that may otherwise be wasted. Likewise, any time spent preparing an experiment or equipment (including general maintenance) saves time and materials and, potentially, may also save a life. 

This section lists fundamental potential pitfalls when working with a vacuum system. If you read no other section in this book, read this one. By following the rules and guidelines that you are directed to within this section, many hours, and perhaps weeks, of problems will be avoided. It is better to avoid the situation of not having enough time to do it right, but plenty of time to repair the wrong. This list is not meant to be comprehensive—it cannot be. It is, however, a collection of the more common disasters that occur on a laboratory vacuum system. 

Sudden bursts of pressure in McLeod gauges that can cause mercury to spray throughout a line (problem) or break a line (big problem) (see Secs. 7.5.6-7.5.9) 

Breaking off glass hose connections when pulling flexible tubing off (see Sec. 7.3.17) 

Breaking a cold trap off a vacuum line by not venting it to the atmosphere before removing the bottom (see Sec. 7.4.4) 

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