Disk-type cutoff and flow control valve

A valve comprising:

• a housing having an inlet port;
• a valve disk fixed in the housing, having a flat face, centered on the axis, and formed to one side of the axis with an axially throughgoing aperture aligned with the inlet port;
• a valve body rotatable about the axis in the housing and formed with an outlet port;
• and
• a normally rotary movable valve disk coupled to the body, having a flat face bearing on the fixed-disk face, and formed to one side of the axis with an axially throughgoing aperture aligned with the outlet port, whereby on rotation of the body and rotary disk about the axis relative to the fixed disk and housing the apertures are moved between an aligned position in which fluid can pass through the apertures and a nonaligned position in which each disk at least partially blocks the aperture of the other disk, one of the disks being formed at the respective face to the other side of the axis with a recess open axially toward the other disk, offset from the respective aperture, and positioned so as to be exposed by the aperture of the other disk in the nonaligned position and covered by the other disk in the aligned position.