fyi
 -----Original Message-----
From: 	Diemont, Frank R.  
Sent:	Tuesday, February 19, 2002 5:34 PM
To:	Craig, Rick; Maestas, Gary; Alexander, James C.; Plachy, Rich; Alters, Dennis; Bryant, Mike; Bellard, Dannis; Rich Jackson (E-mail); Sealy, Les; Teal, Mike
Subject:	CS 17 Recip Gas Aftercooler Vibration Problem 

After Mike Teals' call this morning about the excessive vibration problem at CS 17, I proceeded with the following actions :

1.	I checked with construction and advised them to remove the 4" blowdown/purge valves at the end of the inlet and outlet gas cooler headers.  This should reduce the worst vibration problems.
2.	I  contacted Marvin Barta with MLB Engineers who performed the acoustical/mechanical piping study for CS 17.  We had implemented his piping recommendations in the drawings.
3.	Marvin Barta, Scott (?). and myself are planning to be at CS 17 on Thursday 2/21 and Friday 2/22 to measure pulsation and vibration levels.   The five units will need to be running  to take these measurements.  Pressure taps need to be used to connect the instruments.  Rich Jackson told me that taps are installed on the inlet lines to the coils and at the cross-over valve.   CS 17 Operations, please identify additional taps on the discharge of the compressor units.  With the pulsation data, we should be able to analyze the vibration problem and make recommendations.  I have not yet verified that the units will be on-line on Thursday and Friday. 
4.	I just received a call at 5:15 PM from Rich Plachy at CS 17.  The station is on line with a 160 psig differential and vibration levels are much lower than this morning.  They are the highest at the end of the cooler.  When the station was shut down this morning because of the excessive vibrations, the differential was at 150 psig.  I believe that the removal of the blowdown valves at the end of the headers contributed to the vibration reduction.    I also believe that the support piers under the two headers are not sufficient and that another pier needs to be installed at the end of each cooler header.  We still intend to travel to CS 17 to collect pulsation data.