Air release valve with elastic rolling shutter

摘要

An air release vent valve used to vent air from a liquid filled pipeline, the air release vent valve having a float valve deployed in a float valve housing extending from the pipeline and a surge suppressing shutter valve deployed in a vent passageway extending from said float valve housing such that said surge suppressing shutter valve is downstream from said float valve. The surge suppressing shutter valve includes an elastic shutter element that is pre-shaped to a normally open position and is configured to gradually deform to a closed position as a velocity of air flowing through said vent passageway increase so as to dampen the force of the closure of air release vent valve and prevent a pressure surge within the pipeline. Once a liquid level in the pipeline reaches the float valve, a float is raised so as to fully closes the vent passageway.

主权项

1. A surge suppressing shutter valve used to vent air from a liquid filled pipeline, the surge suppressing shutter valve comprising an elastic shutter element deployed in a vent passageway extending from the pipeline, said elastic shutter element being pre-shaped to a normally open position and configured to gradually deform to a closed position as a velocity of air flowing through said vent passageway increases, so as to dampen the force of the closure and prevent a pressure surge within the pipeline,
wherein said elastic shutter element is configured to progressively close said vent passageway such that said shutter valve provides a first stage of air venting in which increasing pressure difference across the shutter valve results in a first maximum flow rate through the shutter valve, and such that a further increase in pressure difference across the shutter valve brings said elastic shutter element to said closed position, resulting in a second stage of air venting having a lower flow rate than said first maximum flow rate, wherein said elastic shutter element is configured such that said pre-shaped normally open position includes a “U” shaped cross-sectional contour with reentrant extremities.