Abstract: Main technical features of a sealing mechanism of a pressure vessel provided by the invention are a sealing unit for airtightly combining with the vessel, and a combination unit for positioning the sealing unit in the airtight combination state, and there are common structures disposed between constituent elements of the sealing unit and the combination unit, so that the sealing unit and the combination unit can be combined with each other in order to facilitate use and storage and to avoid losing or missing parts.

Abstract: A Venturi tube assembly includes: a Venturi tube having a body section with an inlet end, an outlet end and an internal flow passage between the inlet end and the outlet end, a pneumatic sucking passage outward extending from a low static pressure section of the internal flow passage to an outer circumference of the body section; and a blocking member having an exhaustion space for communicating the outlet end with the atmosphere, a blocking body movable between an unblocking position and a blocking position and a micro-section movable between a full open position and a micro-position. When positioned in the full open position, the exhaustion space fully communicates the outlet end with the atmosphere, whereby full amount of airflow is exhausted from the outlet end to the atmosphere. When positioned in the micro-position, only a micro-amount of airflow is exhausted from the outlet end to the atmosphere.