A splitflow valve (100) comprises a tubular body (124), a valve element (120) and a lock (132). The tubular body (124) has at least one lateral bypass port (110). The valve element (120) defines a flow restriction and is moveable along a first direction (111) between a first position (126) and a second position (154). The bypass port (110) is closed by the valve element (120) in the first position (126). In the second position (154) the bypass port (110) is open. The lock (132) maintains the valve element (120) in the second position (154). Further, the lock (132) is deactivatable to allow the valve element (120) to return to the first position (126).