Concentric Valve Skirts

A gate valve comprising:

• a valve body, wherein the valve body is formed with a through-bore therethrough and a gate cavity and wherein the through-bore and the gate cavity intersect and are orthogonal to each other;
• a gate disposed within the gate cavity, wherein the gate is operable to translate along a length of the gate cavity to move between an open position and a closed position, wherein when the gate is in the closed position the gate substantially blocks fluid flow through the through-bore and when the gate is in the open position the gate does not substantially block fluid flow through the through-bore;
• a first stem disposed within the gate cavity and connected to a first end of the gate;
• a second stem disposed with the gate cavity and connected to a second end of the gate;
• an annular seat pocket formed within the valve body proximate to an intersection of the through-bore and the gate cavity and concentric with the through-bore;
• a seat disposed within the annular seat pocket, wherein a surface of the seat is in contact with a surface of the gate when the gate is in the closed position so that a substantial fluid seal is formed between the surface of the seat and the surface of the gate;
• and
• a skirt,
• wherein the skirt has a proximate portion, a middle portion, and a distal portion,
• wherein the middle portion has an opening sized and configured so that an outer edge of the seat mates and conforms with an inner edge of the opening of the middle portion of the skirt,
• wherein the proximate portion extends into a first lubricant pocket formed within the valve body, and the distal portion extends into a second lubricant pocket formed within the valve body, and
• wherein, when the gate is in the closed position, the distal portion contacts the gate to substantially prevent fluid flow between an opening in the gate and the second lubricant pocket.

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 orthogonal to the first direction;
• a slab gate having a first portion and a second portion;
• 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;
• at least one stem coupled to the slab gate for selectively moving the slab gate between the open position and the closed position;
• a seat disposed adjacent to the slab gate and at least partially disposed within a seat pocket formed in the valve body proximate to an intersection of the through-bore and the gate cavity;
• and
• a skirt disposed adjacent to the slab gate, wherein the skirt has an opening sized and configured to receive an outer edge of the seat whereby the skirt is suspended within the gate cavity by the seat.