What should I do if the operation of the forged steel ball valve is stuck and the torque is too large?

On-site emergency response

First, try to slightly open it in the reverse direction and then close it again. Use the medium to flush out foreign objects. For valves that have not been operated for a long time, the packing gland bolts of the valve stem can be slightly loosened, but be careful not to cause leakage. For those with grease injection valves, inject special grease or cleaning agents. If the electric or pneumatic actuator cannot be driven, check whether the air source pressure or power supply voltage is normal. If the valve is stuck in the middle position and cannot cut off the medium, the bypass pipeline should be switched or the load reduced for handling. Contact the manufacturer for on-site solution. Violent force pulling is strictly prohibited.

Common causes and solutions

The adhesion of the sealing surface is usually due to the coking or crystallization of the medium. It can be softened by soaking in a cleaning agent or by blowing with steam in a half-open state, but it is necessary to confirm the temperature resistance of the material. If the packing is too tight or aged, it will cause high frictional resistance. Loosen the cover bolts and apply grease to solve the problem. Foreign objects getting stuck are mostly caused by welding slag and rust. After repeatedly opening and closing several times to try to wash them away, if they fail to do so, they can only be disassembled for inspection and cleaning. Under high-temperature working conditions, metals expand and seize up. The machine needs to be shut down for cooling before operation. When selecting the type, it is recommended to switch to a metal hard seal structure. If the keyway of the transmission components is worn or the worm gear is stuck, the damaged parts need to be disassembled for inspection and replacement.

Daily preventive measures

Valves that have not been used for a long time should be opened and closed at least once a month to prevent adhesion. Regularly apply grease through the grease injection valve for maintenance. It is recommended to select the actuator torque with a margin of more than 1.3 times the normal value. It is recommended that valves with automatic pressure relief function in the valve cavity be selected for liquid medium pipelines to prevent pressure build-up and jamming.

Safety Reminder

It is strictly prohibited to forcibly pull the valve with the force rod. The breakage of the valve stem or damage to the seal will lead to the scrapping of the valve. Before operation, be aware that the valve cavity may be pressurized. Release the pressure first before proceeding to ensure safety.