What is acceptable during the leakage test for metal-to-metal seats?

During a leakage test for metal-to-metal seats, a slight weeping of water is considered acceptable. This tolerance for a small amount of leakage acknowledges that there may be minor imperfections in the sealing surfaces, even in well-manufactured mechanisms. A metal-to-metal seat is designed to create a tight seal under normal operating conditions, but it's common in practice to allow for a slight weep as a way to account for variations in materials, temperatures, and pressures that can affect the performance of the seal.

The focus of such tests is on ensuring that any leakage does not compromise the system's effectiveness, and a bit of weeping indicates the seat is still functioning adequately without a significant failure. In contrast, conditions such as a total stoppage of flow or a noticeable pressure drop would suggest that there are more significant issues with the sealing mechanism that could lead to operational problems.