GATE VALVE

摘要

A gate valve is provided with a flapper mechanism that is disposed in the main body of the valve and automatically works to seal and isolate the main body of the valve from a bonnet. The bonnet is isolated without any manual function or operation. When the flapper valve is in a closed position, the bonnet, gate and gate actuating mechanism can be removed from the gate valve body without isolating the gate valve. This enables the bonnet and associated components to be repaired or replaced while water or fluid under pressure continues to flow through the main body of the gate valve.

主权项

1. A gate valve comprising:
a main body having spaced apart inlet and outlet openings and a through-way formed between the inlet and outlet openings through which water or liquid flows; a gate opening formed in the main body of the gate valve; a bonnet secured to the main body and generally aligned with the gate opening, the bonnet extending from the main body of the gate valve; a moveable gate disposed in the gate valve; an actuator operatively connected to the gate for moving the gate between a closed position and an open position; in the closed position, the gate is disposed in the main body between the inlet and outlet openings and generally prevents the flow of water or liquid through the main body of the gate valve; in the open position, the gate assumes a position at least partially in the bonnet and above at least a portion of the gate opening; an automatic flapper valve moveably mounted in the main body of the gate valve adjacent the gate opening and operative to close the gate opening, the flapper valve being moveable between open and closed positions wherein in the closed position the flapper valve closes the gate opening; and wherein the flapper valve is responsive to the movement of the gate and wherein the flapper valve and gate are configured and positioned relative to each other such that movement of the gate from the open position toward the closed position results in the flapper valve moving to the open position and wherein movement of the gate from the closed position to the open position results in the flapper valve assuming the closed position.