Surface safety valve (SSV) is a hydraulically actuated fail-safe gate valve for testing oil and gas wells with high flow rates, high pressures, or the presence of H2S. The SSV is used to quickly shut down the well choke manifold upstream in the event of overpressure, failure, a leak in downstream equipment, or any other well emergency requiring an immediate shut down.SSV is remotely operated by an emergency shutdown device (ESD), which can be triggered automatically by high- or low pressure pilot actuators. If an emergency occurs, this feature reduces the possibility of personnel injuries. A number of SSV models are available for different well conditions (pressures, temperatures, and flow rates) and with various connections, such as hammer union or API-6A flanges.All SSVs are manufactured under Type Approval or Design Verification Review and provided with a Certificate of Conformity and full quality file.