Like Receivers for Compressed Air System, a suitable method has to be provided to remove liquid from a vacuum receiver. The only difference is that installation of a simple drain valve from the bottom of the receiver will not do the job. The higher atmospheric pressure outside the receiver will prevent any flow of moisture out of it. The receiver has to be isolated and brought to atmospheric pressure. This will be fine for some applications but may do great harm to others.
At PV, we provide a simple extraction system that will automatically extract moisture out of the receiver without the need for isolation and cause a pressure surge (sudden change in vacuum) in the system, during moisture removal process.