| 摘要 |
<p>A valve for use under severe throttling conditions, includes a housing with fluid inlet and outlet passages communicating with a chamber inside the housing. An abrasive resistant throttling tube in fluid communication with the inlet passage projects into the chamber. Also, an abrasive-resistant throttling plug is movably positioned inside the housing so that it can be moved between a first position wherein its end is spaced from the mouth of the throttling tube and a second position wherein it obstructs the mouth of the throttling tube. As mating surfaces of the plug and tube are eroded away by fluid flowing through the valve, the plug is advanced further and further toward the throttling tube so that unabraded surfaces of the plug and tube are presented to one another whereby maximum fluid throttling is achieved despite such wear.</p> |
