Bushings (4): Stem bushing reduces torque and isolates the stem from the valve body, preventing seizure of the stem due to corrosion in the stem journal.

• 衬套（4）：轴衬套有利于减少扭矩，将轴与阀体隔离，防止由于轴颈腐蚀而造成轴旋转困难。