We have a vertical type muti-stage centrifugal pump which operates at 1500 RPM and has smooth operation with vibration limit max of 0.8mm/sec RMS. During shutdown or start-up when the said pump reaches 80 to 90 RPM, its vibration increases significantly i.e. above 80 mm/sec RMS and causes tripping of Steam Turbine and ultimately complex shutdown. Its a classic example of structural resonance but for now we are looking to ensure plant reliability by increasing the delay factor in vibration sensors to allow pump to surpass that RPM. Following are the questions
1. Is there any recommended time delay factor for Vibration probes so that we can add that limit since the issue is limited to a very sort time period
2. Is there any standard that permits time delay setting for different sensors.
Thanks
1. Is there any recommended time delay factor for Vibration probes so that we can add that limit since the issue is limited to a very sort time period
2. Is there any standard that permits time delay setting for different sensors.
Thanks