Surface Control Subsurface Safety Valves (SCSSV) Guide
This is the more widely employed and reliable method. The design of SCSSV - surface control subsurface safety valve is typically aiming to operate independently of well conditions. This is because the downhole valve relies on hydraulic pressure. The pressure is supplied by a small 1/4" monel control line strapped to the tubing to keep the valve open. This control line provides external opening energy, usually hydraulic or electric. Once this energy is lost, the valve will close immediately.
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