Filtering flow in a valve

摘要

A unitary cup-shaped grid member (76) having a grid of holes in the closed end is inserted in the inlet of a valve and a cup-shaped fine-mesh primary filter screen (88) inserted therein and snap-locked in place. In the event the screen clogs and is removed by the user, the grid provides some back-up or auxiliary course filtering to protect the valve in service after removal of the primary filter screen.