Valve assembly for pipeline

A valve assembly comprising:

• a valve body adapted for connection in a pipline and having a first through passage and a body portion providing a socket, the socket including a socket mouth which opens transversely of the first through passage, the through passage extending on either side of the socket;
• a sleeve comprising a annular sleeve body having a second through passage therein and a sleeve mouth which opens transversely of the second through passage;
• the sleeve being rotatably mountable within said socket through the socket mouth thereof with the socket mouth and the sleeve mouth opening in the same transverse direction, the sleeve body being dimensioned so that when the sleeve body is mounted in the socket the sleeve body is rotatable so as to bring the first and second through passages selectively into and out of mutual alignment wherein a composite through passage formed by said first and second through passages is provided;
• the valve body and the sleeve having mutual engagement formations which are out of engagement when the sleeve is in a first predetermined angular position relative to the body, and which are lockable in engagement by relative rotation away from said first predetermined angular positon;
• and
• obturator means mounted generally within the sleeve and displaceable to control a flow through said composite flow passage;
• the obturator means being removable through the sleeve mouth when the sleeve is positioned in a second predetermined angular positon, relative to the body, in which said first and second through passages are out of mutual alignment and in which said sleeve is not disengateable from the valve body.