What is the range of flow rates that must be maintained when welding on liquid piping systems in service?

The specified range of flow rates for welding on liquid piping systems in service ensures that there is adequate cooling of the welded area, which helps to maintain the integrity of the weld and minimize the risk of overheating. When flow rates fall within the range of 1.3 to 4 feet per second, it reflects a balance that allows sufficient fluid movement around the weld area, thus preventing localized heating that can lead to structural issues, such as warping or weak welds.

This flow rate range also helps in managing the thermal dynamics of the material being welded, ensuring that the heat input does not exceed what the piping material can handle without adverse effects. It is essential for maintaining the performance of the liquid piping system while ensuring that the welding process does not compromise the overall integrity of the system.

Careful attention to these flow rates during welding operations is critical, particularly in service environments where the system is under operational conditions, as it affects both the immediate quality of the weld and the long-term reliability of the piping system.