Dynamic slab gate valves

A slab gate valve comprising:

• a valve body formed with a through-bore in a first direction and formed with a gate cavity in a second direction, which is orthogonal to the first direction;
• a slab gate having a first portion and a second portion, wherein the slab gate has a first side and a second side;
• wherein the gate cavity is sized and configured to receive the slab gate;
• wherein the first portion of the slab gate is sized and configured to occlude the through-bore when the slab gate is in a closed position;
• wherein the second portion of the slab gate is formed with a flow aperture for allowing flow therethrough when the slab gate is in an open position;
• an upper stem coupled to the slab gate for selectively moving the slab gate between the open position and the closed position;
• a lower stem coupled to the slab gate and at least partially disposed within the gate cavity;
• a downstroke lubricant cavity formed in a portion of the valve body proximate to the gate cavity for containing a lubricant for lubricating the lower stem in a downstroke;
• a first seat cavity formed in the valve body proximate a first intersection of the through-bore and the gate cavity on a first side of the first intersection;
• a second seat cavity formed in the valve body proximate a second intersection of the through-bore and the gate cavity on a second side of the second intersection;
• a first dynamic seat assembly disposed in the first seat cavity;
• a second dynamic seat assembly disposed in the second seat cavity;
• a first dynamic skirt, disposed adjacent to the first side of the slab gate and disposed between the first seat cavity and the downstroke lubricant cavity, wherein a face of the first dynamic skirt contacts the first side of the slab gate;
• a second dynamic skirt disposed adjacent to the second side of the slab gate and disposed between the second seat cavity and the downstroke lubricant cavity, wherein a face of the second dynamic skirt contacts the second side of the slab gate;
• and
• wherein the first dynamic seat assembly comprises:
• a first cylindrical seat having a first side and a second side, wherein the second side is adjacent to the first side of the slab gate,
• wherein a first debris ring slot is formed on an inner portion of the first cylindrical seat,
• a debris ring proximate the first side of the first cylindrical seat and disposed at least partially within the first debris ring slot,
• wherein the first cylindrical seat is formed with a seat energizer cavity proximate the first side of the first cylindrical seat, and
• a seat energizer disposed at least partially in the seat energizer cavity and operable to urge the cylindrical seat toward the slab gate.