the diameter of the opening 23 corresponds to the diameter of the closing element 6 plus a predetermined play when the closing element 6 is lifted off from the valve seat 4 the direct path from the valve seat 4 to the auxiliary valve seat 19 is blocked as the closing element 6 almost fills the opening 23 accordingly only a small part of the fluid can flow off through the tank connection t during the movement of the closing element 6 the guiding arrangement 22 which is arranged in a retaining part 24 and thus retained in the housing 2 has a guide element 25 in the shape of a bowl which opens in the direction of the valve seat 4 the valve seat 4 is arranged at the top of a pipe element 26 which has a conical outside accordingly a gap 27 is formed between the pipe element 26 and the guide element 25 the gap 27 having over a certain distance in the radial direction a substantially constant thickness at the radial end the gap 27 has an expansion zone 28 above the expansion zone 28 the guide element 25 has a flange 29 with which the guiding arrangement 22 is.