| 摘要 |
<p>A valve system is disclosed in which sleeves providing an unbalanced area are arranged so that the unbalanced area is exposed to the zone of higher pressure and produces a sealing force between the sealing face of the sleeves and a mating valving surface, which force is a direct function of the difference in the pressure across the seal. Adapter rings are positioned behind each seal and a spring provides an initial light bias on the sleeve to urge it into mating engagement with the valving surface. The adapter ring and sleeve structure is arranged so that all of the sleeves, including those sleeves having an external unbalanced area, may be assembled in the valve body from the end of the sleeve receiving passage remote from the valving surface. The adapter rings also make it possible to use standard length sleeves in combination with relatively low cost adapter rings having lengths selected to provide a total sleeve adapter ring length which matches the length of the passages in the valve body.</p> |
