Glass-Lined reactors are used in number of difficult environments. Some are difficult due to the chemistry of the contents, while others are challenging due to the need to protect the contents from contamination. In either case, one of the more important areas to pay attention to is the shaft seal on the agitator. This is the part that prevents the contents of the reactor from escaping during operation, which could cause harm to the environment, the equipment itself, and any personnel in the vicinity. There are a number of different options for shaft seals and it is important to pick one that matches the requirements of the application.