What is a common cause of 'priming' in a boiler?

Priming in a boiler typically refers to the phenomenon where water is carried out of the boiler with the steam. This is often caused by excessive foaming, which can result from the presence of dissolved solids or contaminants in the boiler water. When these substances are present, they can create a foamy surface that interferes with the natural separation of steam and water. As steam is generated, it can carry that foam along with it, leading to water being entrained in the steam lines.

Maintaining proper water quality in a boiler is essential to prevent foaming and ensure efficient operation. Regular treatment of boiler water to remove dissolved solids, and close monitoring of water chemistry can help mitigate this issue.