provide a 100% gastight isolation of gas mains in terms of UVV regulations, without a sealing media. The gastight shut-off is maintained even upon loss of external energy and corresponds to that of a blind flange connection. They are used for the shut-off of blast furnace-or coke gas mains. Actuation may be by electric or hydraulic drives.

The DVGW approved valve is equipped with a double seal landing bar, thereby providing a cavity into which Nitrogen is injected when the valve is closed. The Nitrogen pressure is used to monitor the valve tightness continuously. The sealing element itself is fitted to the valve disc and is easily replaceable.