| 摘要 |
The function of fluid flow control valves and non-return valves are combined to reduce weight and cost where both functions must be provided. The body (20) of the main control valve is cylindrical or spherical and accommodates the rotating control element (1), which in the usual way has inlet (2) and outlet (3) ports and allows passage of the fluid when these are aligned with the pipes (22, 23). A non-return flap valve (4), pivoted (5), at the top of the rotating element is mounted inside it and provides a seat (6) and must be made large enough to prevent the flap from obstructing the passage when fully open. |
