Arrangement for conducting, treating and/or measuring a fluid

A configuration for installation into a pipeline of a fluid network, the configuration comprising:

• an exchangeable functional unit;
• a connection housing having an inlet, an outlet, and a connection opening formed therein for connection to said exchangeable functional unit;
• and
• a core piece rotatably disposed in said connection housing, a rotation of said core piece makes it possible for a throughflow of a fluid through said connection housing to be blocked or released, said core piece having a receptacle for connection of said exchangeable functional unit, said receptacle and said connection opening are oriented in a same direction.