What must be checked before releasing a hydraulic rail puller after welding?

Before releasing a hydraulic rail puller after welding, it is crucial to check the cooling time. This is essential because thermite welding generates extremely high temperatures, and the welded joint must sufficiently cool before any mechanical stress is applied. If the weld is released too early, while the metal is still in a heated or malleable state, it can lead to improper joint integrity, distortion, or even failure of the weld. Allowing the appropriate cooling time ensures that the weld has solidified properly, allowing the material to achieve its full strength and structural integrity.

While other factors, such as rail alignment, weather conditions, and welding angle, might affect the overall process of thermite welding, they are not as critical immediately prior to releasing a hydraulic rail puller. The focus on cooling time is specifically related to the safety and effectiveness of the weld joint.