Vacuum will not be outlined by the force classification in the piping, but by the ability of the liner supported from the housing to resist vacuum collapse. It is easily the most typically disregarded aspect of the process and For that reason by far the most widespread source of failure. https://www.quora.com/profile/Jacques-Donaldson-2/advantages-and-disadvantages-of-glass-lined-reactor-Glass-lined-reactors-are-widely-used-in-chemical-and-pharmaceutical