| 摘要 |
This invention concerns relievable normally closed check valves for use in conjunction with fluid delivery systems for medical patients, as well as methods for making and using valves. In the medical context, such valves function at very low fluid pressures, and include a multi-part valve body made from upper and lower housings capable of movement relative to each other that, when operably connected, dispose between them a compliant or deformable, resilient valve element normally biased in the closed position against a valve seat present on the inner surface of the upper housing. The upper housing also includes a lower housing seat. The inside surface of the lower housing contains or supports a structure that positions the valve element to engage the valve seat in the absence of fluid pressure above the valve's pre-determined cracking pressure. The valve's flow prevention function may be relieved in the absence of sufficiently pressurized fluid by causing the valve element to disengage from the valve seat, for example, by adjusting the valve body to distance the valve element from the valve seat. |
