Abstract: An improved back-pressure valve for heating installations having an annular mask 7 mounted transverse of a channel in a pipe or pump, guiding means 13 affixed to the mask 7 diametrically and extending along the channel, a sealing disc 8 for covering an opening formed by the annular mask and having two diametrically opposed protuberances 12 extending into the guiding means 13 to make the sealing disc 8 pivotally and linearly movable in response to the fluid flow passing through the pipe or pump.

Abstract: An improved back-pressure valve for heating installations having an annular mask mounted transverse of a channel in a pipe or pump, a sealing disc for covering an opening formed by an annular mask, a spring urging it closed, and the sealing disc mounted to be pivotally and linearly movable in response to resulting consequences of vortices in fluid flow passing through the pipe or pump. The sealing disc may have two diametrically opposed protuberances extending into a guide and urged by a spring abating on the protuberances. Also a sealing disc may comprise two superposed sealing discs guided by a stud so that the sealing discs have a relative rotational motion between themselves.