| 摘要 |
A method of measuring the condition of a safety valve (1) is disclosed. The valve (1) to measure has a valve seat, a valve spring, and a valve closure member having an inlet side and biased by the spring into contact with the seat. The method has the steps of determining a first pressure at which when applied to the inlet side of the closure member will cause the valve (1) to start to open, determining a second pressure, lower than the first pressure, at which when applied to the inlet side of the closure member will cause the valve (1) to start to leak with substantially zero displacement of the valve closure member, defining a condition parameter that varies with the difference between the first and second pressures, and then determining a value of the condition parameter thereby to determine the condition of the valve (1). An apparatus is also disclosed for determining the sealing force of a safety valve, the apparatus having a force sensor (2) arranged to measure a valve lift force of the safety valve, a displacement sensor (18) arranged to detect displacement of a valve closure member of the safety valve, a pressure sensor (32) for monitoring the pressure applied by means for applying a fluid pressure to a valve inlet of the safety valve, and a controller (30) arranged to control the valve inlet pressure. The controller (30) will determine the condition of the valve (1).
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