Abstract: A valve disk assembly comprising an inverted cup-like holder accommodating a resilient disk, and being devoid of any fastening means for retaining the disk in the holder. The disk has a hole extending between its faces through which the region between the disk and the top wall of the holder communicates unobstructedly with the low pressure region surrounded by the valve seat when the disk is seated on the valve seat to close the valve. Sealing means, which may be a peripheral lip carried by the disk, restricts flow of high pressure fluid from beneath the disk into the region between the disk and holder. The top wall of the holder may be imperforate or have a hole aligned with the hole in the disk, depending upon the type of valve with which the disk assembly is used.