It is the object of the invention to overcome these shortcomings and disadvantages by providing a flush-mounting flush-sealing diaphragm valve for vertical or horizontal mounting for taking samples from or draining of a container, which valve further has the capability of complete steam sterilization in situ, and substantially without any sedimentation due to the presence of the valve.Water Control valves

The substantially flush-sealing diaphragm valves of the invention are especially directed at use in fermentation tanks and the like where genetically engineered microorganisms or mammalian cells are cultivated and where full containment is demanded with a view to protection of the external environment.

It is also important that the valve housing inlet and outlet and the diaphragm, which come into contact with the fluid, form a fluid-contacted volume being constructed by means of simple geometric forms ensuring optimal "sanitary standard" in an uncomplicated cleaning process. Remaining material, if any, which cannot be washed out of the valve forms a contamination risk even if the valve is sterilized with superheated steam before the fermentation cycle is initiated.

With a view to sampling during fermentation it is very important that a minor sample is absolutely representative of the container volume as analyses of the sample are used to control the fermentation process in the container.Water Power Control Valves

It must be possible to sterilize the valve with steam in the valve outlet during the fermentation without damaging the culture in the tank during the sterilization so that sampling can be performed in a recently sterilized part of the discharge tube.

This is obtained by a diaphragm valve, wherein the valve housing forms an integral part of the container or tank (e.g. by being welded into the wall of the tank), the surface of the diaphragm in closed state is geometrically close to the inner outline of the container, the diaphragm closes and abuts directly against valve seats in both the tank outlet ( valve inlet) and discharge tube ( valve outlet) simultaneously,WATER POWER CONTROL VALVE and wherein no permanent valve chamber is provided.

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