Gate Valve With Equalizer Port

A valve, comprising:

• a valve body having openings for permitting fluid flow through the valve;
• a main gate housed within the valve body, movable between open and closed positions by linear actuation within the valve body, the main gate having opposite outer walls fixed relative to each other for cooperating with openings in the valve body for blocking fluid fluid flow through the valve body between the openings when in the closed position and permitting fluid flow through the valve body when in the opened position;
• at least one pressure equalization passageway formed through the gate for communicating fluid from one side of the gate to the other through ports formed on the opposite outer walls of the gate;
• an internal gate valve disposed within a cavity formed within the gate for opening and closing the pressure equalization passageway, the internal gate valve comprising an internal gate having a port formed therein and a pair opposing valve seats mounted in fixed positions within the main gate on opposite sides of the internal gate, with which the the internal gate has a close-fitting relationship, the pressure equalization passageway extending through the opposing valve seats;
• and
• a carrier for shifting the internal gate between a closed position in which a port formed through the internal gate does not align with the internal passageway and the gate blocks fluid flowing through the internal passageway, and an opened position in which the port in the internal gate aligns with the internal passageway for allowing fluid flow past the internal gate;
• the internal gate being positioned between an upper and a lower structural member of the carrier without being constrained within carrier in directions toward and away from each of the pair opposing valve seats, thereby permitting permitting the internal gate to closely fit between the pair of opposing valve seats.