초록 ▼

An improved surface controlled chemical injection valve and method for injecting chemical fluid into the bore of a tubing string of a well are provided, the chemical injection valve having at least one piston movable in response to the pressure of the chemical fluid, an actuator connected to the pis

An improved surface controlled chemical injection valve and method for injecting chemical fluid into the bore of a tubing string of a well are provided, the chemical injection valve having at least one piston movable in response to the pressure of the chemical fluid, an actuator connected to the piston, and a flow restrictor wherein the pressure of the chemical fluid supplied to the valve from the chemical fluid source acts on the piston to cause the actuator to open the valve and inject the chemical fluid into the tubing string bore. The flow restrictor is mounted downstream of the piston to create sufficient available pressure in the chemical fluid upstream of the flow restrictor to act on the piston and hold the valve in the open position.

대표청구항 ▼

A valve for injecting chemical fluid from a chemical fluid source into the bore of a tubing string of a well, the valve comprising: a housing including a flow passage therein for communicating with the tubing string bore and an opening therethrough communicating with the flow passage and the chemica

A valve for injecting chemical fluid from a chemical fluid source into the bore of a tubing string of a well, the valve comprising: a housing including a flow passage therein for communicating with the tubing string bore and an opening therethrough communicating with the flow passage and the chemical fluid source; a valve closure including a flapper seat connected to the housing and a flapper pivotally connected to the housing, wherein the flapper is movable from a closed position to an open position wherein the valve is open; an actuator in the housing for opening the valve closure and movable from a first position, wherein the valve closure is closed; to a second position wherein the valve closure is open; a flow restrictor in the flow passage, connected to the housing, for creating a pressure differential across the flow restrictor; and at least one piston connected to the actuator, in communication with the fluid source upstream of the flow restrictor, and adapted to move the actuator from its first position to its second position in response to the pressure of the chemical fluid upstream of the flow restrictor; whereby the pressure differential across the flow restrictor results in sufficient available pressure in the chemical fluid upstream of the flow restrictor to cause the piston to hold the valve open.