Control valve for viscous material pumps

A control valve for viscous material pumps comprising:

• a flat housing (2) having a pair of generally parallel exterior surfaces, said housing having a pair of laterally spaced viscous material channels (3, 4) extending therethrough normal to said exterior surfaces, said housing being formed of two parts (5, 6) abutting along a joinder plane lying parallel to said exterior surfaces;
• a valve slide in said housing having a valve plate (10) fastened to valve rod (11) for reciprocal movement within said housing across one or the other of said channels for controlling the movement of material through said channels;
• and
• a wear shell (9) mounted in said valve housing and containing said valve plate with said valve rod extending therefrom, said wear shell being formed of a pair of generally similar halves (7, 8) divided along a central plane (46) lying normal to the movement of said valve slide, said wear shell halves being assemblable to form said wear shell by threading them on opposite ends of said valve rod (11), said wear shell being formed for permitting the reciprocal movement of said valve slide and having a pair of openings aligned with said channels, said wear shell being retained in said housing by locking engagement with the interior of said housing and having annular projections (39, 40) around said openings extending into said channels (3, 4) for lining same.