| 摘要 |
A pipeline vent valve comprising a body (13) defining a chamber (A) having an inlet (17) towards its lower end which is adapted to be connected to a pipeline and an outlet (21) towards its upper end, the outlet defined by a valve seat, a first valve member (23) supported in the chamber to be moveable between a first position at which it is in sealing engagement with the valve seat and a second position at which it is out of engagement with the valve seat, the first valve member in its movement to the first position being responsive to the magnitude of the gaseous flow rate through the valve seat to be moveable to the first position on the gaseous flow rate exceeding a desired level, the first valve member also being responsive to the level of liquid in the chamber and being adapted to close when the liquid level in the chamber exceeds a predetermined level, the first valve member having in opening providing communication to each side of the first valve member, a second valve member fixed to the first valve member to be moveable between a first position at which it is in sealing engagement with the entry of the opening and a second position at which it is out of engagement with the entry of the opening, the float member supported within the chamber and fixed to the second valve member to cause movement of the second valve member between the first and second position as a result of movement within the valve member resulting from the presence of liquid in the chamber.
|
