A 6-way valve (20) comprises two similar 3-way sub-valves (20a, 20b) being mechanically coupled with each other, such that both sub-valves (20a, 20b) are always in the same position, whereby each sub-valve (20a, 20b) has three different valve ports (33, 34, 35) and a valve member (22′) with an internal connecting channel (29), which valve member (22′) can moved between first and second end positions via an intermediate position such that in said first end position the first (33) and third (35) valve ports are connected with each other by means of said connecting channel (29), in said second end position the second (34) and third (35) valve ports are connected with each other by means of said connecting channel (29), and in said intermediate position said connecting channel (29) is disconnected from said first and second valve ports (33, 34).A simple and effective volume/pressure relief means (28) is provided at one of said valve members (22′), which volume/pressure relief means (28) establishes a hydraulic relief connection between said first or second valve port (33, 34) and said third valve port (35) of the respective sub-valve (20a or 20b), when said sub-valves (20a, 20b) are in said intermediate position, and is inactive, when said sub-valves (20a, 20b) are in the first or second end positions.