Valve arrangement adaptable to meet different leakage requirements

A valve arrangement adaptable to meet different requirements with respect to leakage comprising:

• a housing including a part on which a neck is formed,
• a shut-off element rotatably disposed in the housing,
• a shaft which extends outwardly through an opening in the housing and is coupled to the shut-off element for rotation therewith, the shaft having a coating which extends beyond an axial end face of the neck,
• a first sealing element disposed in a first annular space between the shaft and the neck for sealing the shaft,
• a bushing disposed around the shaft and movable axially therealong to compress said first sealing element against the shaft and the neck,
• a lining in said housing, said lining extending into said neck and into contact with said first sealing element, and
• a one-piece annular body optionally disposed on the axial end face of the neck, with a second annular space being provided between a lining on an inside surface of the annular body and the shaft over a total height of the annular body and a second sealing element disposed in said second annular space such that the bushing can also compress said second sealing element,
• the second annular space having a radial width which is substantially the same size as the first annular space, the annular spaces directly adjoining one another,
• the annular body lining directly adjoining the housing lining,
• the bushing being joined by bolts passing through bores to the neck,
• the neck being circumferentially continuous, being provided internally with the housing lining over its entire height, and having a step located between the first sealing element and the rotatable shut-off element.