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..
There are many types of valves available in the market for example gate valve, globe valve, ball valve and many more. Mostly commonly used shutdown valve is Ball valve.
• Ball valves are used for straight fluid flow
• Butterfly valve and swing gate valve are used for air intake shutdown valve.
This is a ball valve type shutdown valve, which permits the flow across a pipeline. There is an inlet side and there is an outlet side. In an open position, the flow is allowed across the pipeline and in the closed position the flow stops.
There are many valve actuator available, but there is something which we should consider to decide which one is suitable for the shutdown valve and also for the preparation of the process system. As the function of SDV for emergency needs the actuator must be able to close the valve quickly ie the standard timing is 3 secs. We must explain to the vendor that they must make calculations for this actuator and this will be adjusted with the value to be used, adjusting the needs to stroke power to close the valve. Often used actuator type is single acting spring return.