Hydraulic valve for door closing device

摘要

The valve comprises a valve seat and a valve section, such as a ball (6), slide, etc., which are arranged in a flow channel (51). The ball produces at least one second sealing surface (56a,b) alongside a first sealing surface (55), with the sealing faces arranged in sequence in the flow channel. The first sealing surface forms a metal to metal seal and the second sealing surface forms a metal seal with an elastic material seal. All of the sealing surfaces are loaded directly or indirectly by the valve ball or co-operate with it. One sealing face is conical and is mounted on or borders on a conical surface (52), where the conical surface acts as a transition between a first channel sector of smaller section (51a) and a second channel sector of larger section (51b).