Online automatic welding method and system for welding seam of valve sealing lip

The invention discloses an online automatic welding method and system for a welding seam of a valve sealing lip. The online automatic welding method for the welding seam of the valve sealing lip comprises the steps that S1, a handle on a valve is detached, and a valve rod is exposed; s2, the self-adaptive clamping device is arranged on the valve rod in a sleeving mode and locked on the valve rod; s3, the automatic cutting device is mounted on the self-adaptive clamping device; s4, an automatic cutting device is started, and the original sealing lip weld joint is cut off; s5, the automatic cutting device and the self-adaptive clamping device are dismantled, a valve element, a valve rod and a valve sealing face of the valve are inspected, and reassembly is conducted after inspection is completed; s6, the step S2 is repeated, and the automatic welding device is installed on the self-adaptive clamping device; s7, the automatic welding device is started, and a new sealing lip welding seam is formed through welding