Pressure difference relief valve for liquid containers

摘要

A pressure difference relief valve, viz. a pressure relief valve or a vacuum relief valve, for a liquid container has a valve body which opens or closes a valve opening of a valve housing in response to the pressure difference between the interior of the valve housing and the ambient atmosphere. The valve body is connected to a slidably mounted stem. The valve is constructed with spring elements which are clamped against the stem from opposite sides thereof at a controlled force to create a frictional resistance to sliding movement of the stem. Hereby any tendency of the valve to vacillate between the closed position and a fully open position under the influence of fluctuations of the gas or air flow, e.g. caused by turbulence, is eliminated or reduced.