If the pilot valve spring coupled driven sleeve, inhibited the spring swing to lead more stable valve movement.
若导阀弹簧配上导向套筒，则可抑制弹簧的摇摆，使导阀芯运动更平稳。
2
Hence, multi-layer polymer injection allocator with single-tubing and sliding sleeve switch is developed, and development, lab experiment and pilot test of this polymer alloca...