| 摘要 |
A valve block 100 comprises a valve 112, a spindle 114 having a shaft 116 rotatable within the valve block 100 for pivoting the valve 112 between open and closed positions, and a bore 118 extending within the valve block 100 for locating the shaft 116. A split bush (128, 130, Fig. 13B) is located within the bore 118 and encircles the shaft 116. A recess (132, Fig. 13B) is defined between the bush 128, 130 and the shaft, and first and second seal elements 134, 136 are located within the recess 132. A biasing element 138 is located within the recess 132 intermediate the first and second seal elements 134, 136 and is configured to expand axially to apply opposite forces to the first and second seal elements 134, 136. |
