Abstract: A valve wherein the housing has a first section with a hemispherical socket in one of its surfaces and a second section which overlies the one surface and confines a rotary hemispherical valving element in the socket. A polygonal extension of the valving element is rotatable in and extends through the second section to facilitate rotation of the valving element by means of a handle between a first position in which each two channels in the valving element communicates with a discrete pair of passages in the first section and at least one second position in which the channels are sealed from the passages. Sealing rings surround the passages adjacent the socket and are biased against the valving element by dished springs.