Ball valve VSF

pneumaticshut-offfor oil

The function of the shutdown valve is to shut-off the fluid flow inside the fluid flow line or pipe when an emergency that leads to a hazardous situation comes. It is an actuator operated valve mainly used for safety purpose that is why it is called Emergency shutdown valve. It is also known as the shutdown valve or SDV, ESDV, ESV, ESD It is very important that every instrument engineer must know where the shutdown valve is installed, what fluid flow through it and what standard is used as the design reference. These shutdown valves are commonly used in oil and gas field in order to reduce the escalation of hazards from one system to other. shutdown valve features : i) Tie Shut Off a shutdown valve must possess Zero/minimum leakage. Generally, it should pass the seat leakage testing as per API 508 and/or ISO5208. ii) Fire-safe shutdown valve must work even though it is exposed to external fire attacks. Thus, shutdown valve body shall be fire-rated according to API 607 for soft seated valve or API 6FA for API 6A & API 6D valves or BS 6755 Part 2. iii) Fast action (From Full Open - Full Close) The actions of the shutdown valve must be fast. A quarter ball valve is best for quick action. According to thumb rule, shutdown valve shall be able to close within 10 seconds of activation, and time taken from Full open to Full Close must be within 1-2 seconds per inch of shutdown valve size. Therefore, proper selection and sizing of the actuator must be ensured and all requirements must be fulfilled. iv) Minimum passing (when closed) This feature is needed to minimize the potential of the overpressure of a low-pressure system and spurious trip.