A connecting element for connecting ports of a valve array's valve attachment block to a supply block may include first engagement elements on one side for establishing a connection to the ports, and second engagement elements on another side for establishing a connection to the supply block. The first and second engagement elements may be configured to establish gas-tight connections, wherein the connecting element includes a flexible material. In a further combination, the supply block has an attachment side for attaching tubes to the supply block and a connection side for connecting the supply block to the connecting element, the connection side having engagement elements which are engageable with the second engagement elements of the connecting element for establishing a gas-tight connection. The supply block may be less flexible than the connecting element. A further combination may include the valve array.