May I ask if the blowdown gate valve for the steam pipeline should be removed?
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Is it necessary to remove the gate valves in the plant boundary area for the first purge of the 4.0 MPa steam pipeline? If it’s not removed, pipeline welding slag and rust might damage the sealing surface of the gate valve. Please ask a professional for some advice, thank you!
It is impossible for slag and rust to damage the sealing surface of the gate valve; what is possible is that slag and rust get stuck in the guide grooves of the gate valve, preventing it from closing properly.
If it is the last valve, it cannot be removed; it is used to adjust the steam volume. The middle part of the pipeline is generally not disassembled either; the purging flow rate is high, making it difficult for debris to remain there. However, what matters most is the level of cleanliness maintained during construction – it cannot be too dirty, especially in terms of large weld slag and other foreign objects. Valves with a pressure rating of 10.0 MPa are all welded valves and cannot be removed; control is mainly achieved through the construction process.
It is generally not necessary to remove it, as welding slag does not tend to remain inside the gate valve channel.
If it is not the last valve, open it fully to minimize the erosion of the sealing surface by slag, rust, and other debris. After the purging was completed, even the last valve could no longer be sealed properly.
Once the valve is removed, it’s no longer possible to control the purging