Lubricated water valve

In a water valve having a stationary outer member with a cylindrical bore centered on an axis, having opposite axially spaced extremities, and provided with at least one lateral inlet port and a lateral outlet port axially offset from said inlet port,

• a piston axially displaceable between axially offset end positions in said outer member and formed with an internal channel closed at its ends, said piston being further provided with peripheral apertures enabling said channel to communicate with said inlet and outlet ports in one of the axial end positions to establish a flow path therebetween while being disaligned from at least one of said ports in the other axial end position to interrupt said flow path,
• respective end seals on said outer member engaging the piston and fluidically separating said ports from the extremities of said bore, the piston having end portions displaceable to the respective extremities and past the respective seals on axial displacement of the piston between its end positions, and
• a seal on the outer member around the inlet port and engaging the piston, the improvement wherein
• the inner surface of said outer member is provided at said extremities with respective inwardly open peripheral recesses open toward the piston;
• and
• respective bodies of grease generally fill the recesses, the grease being entrainable by the end portions of said piston during axial reciprocation thereof past the respective end seals and the inlet-port seal for lubricating same and adjacent areas of contact between said piston and said outer member.