1 b also comprises a stop surface 20 there are also an aerating opening 56 in the outer housing to prevent any trapped fluid between the internal body 2 and the outer housing 1 from stopping the movement between the internal body 2 and the outer housing 1 this opening 56 may also be connected to a source of hydraulic fluid to operate the device between a closed and an open position in such a configuration there will be appropriate sealing elements arranged between the internal body 2 and the outer housing 1 and a skilled person will understand how this is done the internal body 2 comprises in this embodiment a first part 26 and a second part 27 connected by a threaded connection 28 the first part 26 comprises an internal bore 3 connected with the inlet 7 of the outer housing 1 so that the inlet 7 leads directly to the internal bore 3 without any deviation of the flow of fluid through the device other than possibly passing an orifice 8 to give the flow of fluid through the valve device a most direct route with reduced pressure loss the first part 26 further comprises an aerating opening 55 connecting the internal bore 3 with an chamber 52 formed between the outer housing and the internal body and the stop surface 30 of the outer housing and a stop surface 21 formed in the outer wall of the internal body limiting the movement of the internal body 2 relative the outer housing in the open state of the valve the first part 26 of the internal body 2 comprises also slots 4 running from the internal bore.