It is found that all the variable springs used in the piping are loaded as
designed (Nozzle loads are in allowable limits). But it is observed that
the turbine casing shows a tilt as observed by using filler gauges, in the
DE side while in operation. What could be the cause of this phenomenon?
Could this lift have direct relationship with the vibration levels?
The machine in question has weathered seismic loadings of high intensity !! How exactly do the seismic loadings affect the machine performance and What could be the definite checks during shutdown after a seismic event ,to ascertain whether piping has caused the mechanical deterioration of the machine or not ?!! Can conventional seismic analysis using standard software be of any help.
Regds
"SARE, RALPH H." <SARERH@YANPET.SABIC.com> on 03/20/2002 05:22:44 PM
Please respond to <a href="/group/PipingDesign/post?postID=FpQIX7v5ltSdQC7N76qi_rNPmtGi9p7F-WVIvykMpoeeJ2B3t27MKPYC44cbaJ0bRNUvEEKA-eWVV73RyKJXp85AWUAJ">PipingDesign@yahoogroups.com</a>
To: "'PipingDesign@yahoogroups.com'" <PipingDesign@yahoogroups.com>
cc:
Subject: RE: [PipingDesign] Steam Turbine vibrations
basically the critical steam line will be the one downstream of the steam separator going to the trip and throttle valve. Then the pipe spool between the T&T and the turbine nozzle. Part of the pipe installation procedure (im sure that your vendor rep will require to check this too)is to ensure that the offset (angular and/parallel) is within the construction limits specified by the rtubine mfr at the turbine nozzle. Normally i would rig up a dial indicator on the flange joint during the bolt tigthening and then i would check the cold set of all the variable springs installed on the turbine deck. do the same thing during the hot run. record all readings and use this as the baseline during subsequent mro. In this way, if vibration goes up you can eliminate the piping.
the vibration trend is always compared back to the baseline.
-----Original Message-----
From: KAUSTUBH JOSHI [mailto:kvj@epc.ltindia.com]
Sent: 20 March, 2002 1:44 PM
To: <a href="/group/PipingDesign/post?postID=FpQIX7v5ltSdQC7N76qi_rNPmtGi9p7F-WVIvykMpoeeJ2B3t27MKPYC44cbaJ0bRNUvEEKA-eWVV73RyKJXp85AWUAJ">PipingDesign@yahoogroups.com</a>
Subject: RE: [PipingDesign] Steam Turbine vibrations
yes, generally if the piping is operated with the same operating
parameters,
then the piping should not be the cause of steam turbine vibrations. As if
this would have been the case, the vibration levels would have been high
right from the installation conditions, which is not the your case.
I think, you should target on the steam turbine, various rotating parts of steam turbine and foundation system of the steam turbine.
Your use of Yahoo! Groups is subject to <a href="http://docs.yahoo.com/info/terms/">http://docs.yahoo.com/info/terms/</a> Received on Sat Mar 30 09:04:00 2002
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