Sealing plug arrangement, housing and accumulator

A sealing plug arrangement for sealing a combined filling and degassing opening of an accumulator, wherein the sealing plug arrangement comprises:

• a valve part, a valve holder, and a sealing plug, wherein the valve part is arranged on the valve holder and forms an openable valve mechanism with the valve holder configured to seal at least one interior space of the accumulator from a surrounding area upon pressurization, wherein the sealing plug comprises at least one fastener configured to fix to a filling and degassing opening and at the same time to subject the valve part to a pretensioning force toward the valve holder, wherein the valve holder comprises at least one extension axially projecting toward the valve part which is formed as a circumferential sealing edge on an upper surface facing the valve part on which the valve part rests, wherein the at least one extension comprises a tapered surface that axially tapers from the upper side of the valve holder toward the valve part, the valve part comprising a retaining section, wherein the retaining section of the valve part extends into an inner cavity of the valve holder, wherein the valve part includes a sealing section extending radially outward from the retaining section to a distal end of the sealing section, wherein a surface of the sealing section is planar and configured to abut the circumferential sealing edge of the valve holder, wherein the inner cavity of the valve holder is configured to at least partially block lateral movement of the valve part with respect to the valve holder, wherein the inner cavity comprises a first diameter at a first end of the inner cavity and a second diameter at a second end of the inner cavity, distal to the first end, and the inner cavity has a constant taper between the first end and the second end of the inner cavity of the valve holder, and according to which the circumferential sealing edge comprises a diameter greater than the diameter of the inner cavity, and wherein the at least one extension is formed from a harder material than a material of the valve part.