A slaughtered pig part processing plant including a plurality of pig part processing stations (40, 100, 200, 300, 400, 500) and a conveyor supporting via respective couplings a plurality of spaced apart clamp structures for carrying said pig parts, said conveyor advancing said couplings with a respective clamp structure in a machine direction, - said couplings each comprising an upper structural part and a lower structural part connected with said clamp structure, - said lower structural part being mounted for rotation about a vertical axis relative to said upper structural part, - said lower structural part comprising an upper body having a periphery defined by a number of first edges extending at a first level, and a lower body having a periphery defined by a number of second edges extending at a lower second level, - said processing plant further including: i) one subset of guiding faces (58', 58") at said first level for engaging said upper body to bring about a rotation about said vertical axis when said coupling is advanced in said machine direction past said one subset of guiding faces (58', 58") and ii) another subset of guiding faces (60', 60") at said second level for engaging said lower body to bring about a rotation about said vertical axis when said coupling is advanced in said machine direction past said another subset of guiding faces (60', 60"), characterised in - said upper and lower bodies (34, 35) being fixed to one another, - said upper and lower bodies (34, 35) having the same contour, - said upper body being angularly offset at an angle (α) about said vertical axis relative to said lower body, and - said clamp structure fixed to said lower body, and in - said plant including, upstream or downstream of said two subsets of guiding faces, a group comprising at least one elongated guiding face extending along said machine direction at one or the other of said levels, for preventing or restricting said rotation of said lower structural part by engagement with an edge (34', 35') of said upper or lower body (34, 35), or - said plant including, upstream and/or downstream of said two subsets of guiding faces, a group of two elongated guiding faces (GF1, GF2) arranged opposite one another and extending along said machine direction, both at one or the other of said levels, for preventing or restricting said rotation by engagement with an edge (34', 35') of said upper or lower body (34, 35). - said couplings each comprising an upper structural part and a lower structural part connected with said clamp structure, - said lower structural part being mounted for rotation about a vertical axis relative to said upper structural part, - said lower structural part comprising an upper body having a periphery defined by a number of first edges extending at a first level, and a lower body having a periphery defined by a number of second edges extending at a lower second level, - said processing plant further including: i) one subset of guiding faces (58', 58") at said first level for engaging said upper body to bring about a rotation about said vertical axis when said coupling is advanced in said machine direction past said one subset of guiding faces (58', 58") and ii) another subset of guiding faces (60', 60") at said second level for engaging said lower body to bring about a rotation about said vertical axis when said coupling is advanced in said machine direction past said another subset of guiding faces (60', 60"), i) one subset of guiding faces (58', 58") at said first level for engaging said upper body to bring about a rotation about said vertical axis when said coupling is advanced in said machine direction past said one subset of guiding faces (58', 58") and ii) another subset of guiding faces (60', 60") at said second level for engaging said lower body to bring about a rotation about said vertical axis when said coupling is advanced in said machine direction past said another subset of guiding faces (60', 60"), - said upper and lower bodies (34, 35) being fixed to one another, - said upper and lower bodies (34, 35) having the same contour, - said upper body being angularly offset at an angle (α) about said vertical axis relative to said lower body, and - said clamp structure fixed to said lower body, and in - said plant including, upstream or downstream of said two subsets of guiding faces, a group comprising at least one elongated guiding face extending along said machine direction at one or the other of said levels, for preventing or restricting said rotation of said lower structural part by engagement with an edge (34', 35') of said upper or lower body (34, 35), or - said plant including, upstream and/or downstream of said two subsets of guiding faces, a group of two elongated guiding faces (GF1, GF2) arranged opposite one another and extending along said machine direction, both at one or the other of said levels, for preventing or restricting said rotation by engagement with an edge (34', 35') of said upper or lower body (34, 35).