| 摘要 |
<p>The invention disclosed is a three-way weir valve. The valve housing has a common flow duct and two additional flow ducts, all connectable to external flow lines. A weir with two valve seats on opposite sides of the weir separates the common flow duct from the two additional flow ducts. Two coaxial diaphragms are arranged to engage with the weir valve seats. The common flow duct communicates with one flow duct over one of the weir valve seats and communicates with the other flow duct over the other weir valve seat. The two diaphragms are engaged with compressors connected to pistons engaged in pneumatic cylinders. An air line connects the two pneumatic cylinders. One diaphragm and compressor are biased towards engagement with its other weir valve seat resulting in a normally closed position. The other diaphragm is biased away from engagement with its weir valve seat resulting in a normally open position. Actuation of the pneumatic cylinders moves each diaphragm in a direction opposite each respective diaphragm's bias. Where fluid is flowing into the valve by way of the common flow duct and then to one of the flow ducts, actuation of the pneumatic cylinders transfers the fluid flow path from one flow duct to the other flow duct.</p> |
