A bleed valve is a valve that you use to isolate the flow of air or fluid. Most of the time, they are used in industrial applications, including heavy-duty gas turbines or piping systems. Bleed valves have a small inlet that can prevent fluid or air from flowing through, and the primary purpose is isolation. It can be shut off so that it prevents the emission of harmful gas.
What Is a Double-Block Bleed Valve?
A double-block bleed valve is made to prevent any leakage, which allows maintenance and repair to be done quickly. It is used in many different applications, including fueling systems. It doesn’t require another part to seal it off because there is no contact between slip seals and the seating ring. It is a combination of two ball valves and a needle valve, and the needle valve is in the middle. In addition, it doesn’t need to be lubricated.
How a Double-Block Bleed Valve Works
The double-block bleed valve offers excellent isolation, so it is used in many different industrial applications. These are especially prevalent in situations where an industrial system requires proper isolation, such as processes that have toxic gas. There are two seating surfaces, so they can block both the upstream and the downstream sides of the valve. They are commonly used in pipeline systems to provide isolation. When the valve is closed, it provides full isolation.
It Offers Positive Isolation
Positive isolation is where you isolate part of the plant from the operating section. This might be a level gauge or pressure indicator, and the bleed assembly and shutdown side can be drained. This helps to empty trapped fluids or air from the space between the two blocked valves. A double isolation bleed valve is a single valve that has two seating surfaces, and it provides a seal against pressure. You can choose your bleed valve based on your pressure level, and you should look at the seal integrity. You also need to look at the isolation stability and the monitoring capability. You can use them for pressure measurement, instrument drain, gauge isolation, piping and instrument interface, and other automatic shutdown systems. Make sure that you find high-quality bleed valves that are fire tested and work for your applications.