Multi-path valve structure having extended life and backwashing capability

In a flow control valve wherein a spool valve member is movable within a sleeve to open and close fluid passageways in said valve, a rigid structure forming part of said sleeve for dividing the flow entering and leaving said passageways into a plurality of streams comprising a stack of laminar disks having abutting faces and internal edge surfaces adjacent lands of said spool member,

• said stack of disks including a first flow path across said stack, said first path including a first series of chambers connected to each other through a first series of orifices, thereby providing restricted flow in an inside to outside direction and substantial pressure drop across each of said orifices;
• a second flow path across said stack, said second path including a second series of chambers connected to each other through a second series of orifices, thereby providing restricted flow in an outside to inside direction and substantial pressure drop across each of said second series of orifices;
• a third flow path across said stack directing a backflushing flow across said first series of orifices;
• and
• a fourth flow path across said stack directing a backflushing flow across said second series of orifices, movement of said adjacent land a small increment from null in a first direction opening said first flow path and further movement in said first direction opening said fourth flow path, and movement of said land a small increment from null in a second direction opening said second path and further movement in said second direction opening said third flow path.

In a flow control valve wherein a spool valve member is movable within a sleeve to open and close fluid passageways in said valve, a rigid structure forming part of said sleeve for dividing the flow entering and leaving said passageways into a plurality of streams comprising a stack of laminar disks having abutting faces and internal edge surfaces adjacent said spool member,

• said stack of disks including a first group of disks each of which has a pattern of openings therethrough including at least one opening at its internal edge surface,
• a second group of disks having a pattern of openings including an internal edge openings and other openings in registry with corresponding openings of said first group plus an additional internal edge opening,
• a third group of disks communicating with the openings in said first and second disks and having a large slot extending from the inside to the outside edges thereof, one of said second and third groups of disks having a plurality of series of orifices therethrough,
• said orifice disk having at least one opening at an internal edge surface thereof in registry with internal edge surface openings of others of said disks, said opening being radially aligned with at least one orifice of one of said series of orifices,
• said stack being aligned with at least one land of said spool valve member when said member is in null position such that flow through said stack is blocked and when said land is moved an initial increment from null in a first direction flow is directed in a first path through said internal edge opening of one of said first group of disks, through one of said series of orifices to a chamber defined by registering openings in the other of said first group of disks and the adjacent disk of said second group, across another of said series of orifices to a chamber defined by registering openings in the first of said first and second group of disks and continuing from orifice to chamber until flow passes through an orifice into an outlet passage formed by an opening in an external edge surface of at least one of said disks, and when said land is moved an additional increment, additional flow is directed in a second path through an internal edge opening of at least one of said second group of disks, through one of a second of said series of orifices to a chamber defined by other registering openings in the other of said first and second groups of disks, across another of said second series of orifices to a chamber defined by other registering openings in the first of said second group of disks and continuing from orifice to chamber until flow passes through an orifice into an outlet passage formed by at least one opening in an external edge surface of two of said disks, and also through a large opening in parallel with the flow through said orifices.

In a flow control valve wherein a spool valve member is movable within a sleeve to open and close fluid passageways in said valve, a rigid structure forming part of said sleeve for dividing the flow entering and leaving said passageways into a plurality of streams comprising a stack of laminar disks having abutting faces and internal edge surfaces adjacent lands of said spool member;

• said stack of disks including first flow paths and second flow paths across said stack entering said stack at each end thereof, said flow paths comprising a series of chambers connected to each other through first and second series of orifices, thereby providing restricted flow and substantial pressure drop across each of said orifices, and a third flow path in parallel with said first flow paths offering much less restriction to flow, said stack including a first group of disks at its outside edges each of which includes at least one opening at an internal edge surface thereof communicating with said first flow path;
• a second group of disks adjacent said first group having a pattern of openings in registry with openings in said first group communicating with said first series of orifices plus other openings including at least one additional opening at an internal edge surface communicating with said second series of orifices;
• a third group of disks adjacent said second group, each of which includes an opening at an internal edge surface opening into a slot extending to the outside edge of said stack, thereby providing at least a part of said third flow path;
• means including said series of orifices communicating with chambers formed by the openings in the disks of said first, second and third groups, such that an initial increment of movement of said valve member in either direction away from null causes flow to be directed through said first flow path and further movement causes flow to be directed through said second flow path and said third flow path.