1. Sub-synchronous Vibration in Jet Pumps (Coke cutting)
Humberto Gonzalez, P.Eng.
“DISCALIMER:  This presentation is provided for informational and illustrative purposes only.   Neither Suncor Energy Inc. nor any of affiliates or contractors make any express or implied guarantees, representations or warranties in respect of the completeness or accuracy of any information, conclusions or outcomes expressed in this presentation.   Suncor Energy Inc., its affiliates and contractors are not responsible for and are hereby released from any liabilities whatsoever for any errors or omissions in the presentation and for any liabilities or losses arising out of a  person’s or entity’s use of or reliance on the presentation or any information contained herein”

2. Humberto Gonzalez, P.Eng
Presenter Name
Humberto Gonzalez, P.Eng
He is a Rotating Equipment Advisor for Suncor Energy in Oil Sands and In-situ, he provides Rotating equipment technical support for high economic and environmental impacts at Suncor business, looking for problem resolution at medium and long term, over entire equipment life cycle, from initial design to trouble shooting issues by advising in all technical matters. Prior his current position he worked as Reliability Rotating Equipment Engineer for 6 years since January 2007 at Suncor Energy located in Fort McMurray Upgrading, also worked at Valero Aruba Refinery for 3.5 year from June 2003 to December 2006, as Reliability Rotating Equipment Advisor, contracted by Flowserve for pumps and seal improvement plan, also worked for 12.5 year in different refineries in PDVSA Venezuela as Reliability Rotating Equipment Engineer.
  Mr. Gonzalez Graduated from Zulia University with B.S degree (Mechanical Engineering, 1990), and registered as P.Eng in Alberta Canada.

3. System description
2 pumps, 1210 USGPM ( ft (3109 mt) , 5000 hp (3730 KW), RPM, BB5 (Between Bearing Multi-stage, 8 stgs).
Part of a decoking system, for Delay Coker Drums (6 drums)
100% spare installed, driven by E-motor and Gear box
Decoking control system with pneumatic actuator and valve
Decoking valve positions at:
Minimum flow
Pre-fill
Cutting coke pilot
Cutting coke annular

4. Process schematic Photo Courtesy of Flowserve Corporation

5. Problem Definition
52G-315A pump presented high vibration since 2010 till 2012, with a predominant peak at 0.8 X.
Predominant vibration suspected to be induced by piping pulsations; several adjustments on pipe supports were made without success.
Pump not available 100%, due to repeated radial vibration trips.
Sub-synchronous frequency amplified during pilot and annular coke cuts (highest load condition).
Thrust bearing axial load increased towards the active side, requiring alarm and trip set point adjustments in every drum cut.

6. Pump inspection and findings
Inspected thrust bearing with pump OEM support. Thrust lock nut found loose requiring field adjustments. Upon start up thrust bearing end float increased to alarm levels.
Pump rotor 1st critical speed 5652 RPM (30% separation) at worn clearances.
Sub-synchronous frequency 0.8X, was exciting a natural frequency around the pump system.
Pump removed to the OEM shop for inspection; found generalized corrosion, affecting wear rings and balance drum clearances.
Corrosion caused by high content of chlorines (>500 ppm) present in the water stream.

7. Solution
Sub-synchronous frequency disappeared. Pump 100% available, with two years operation without problems as a result of:
Material upgrades (suitable for high chlorides applications) on pump bundle and impeller wear rings.
Implemented Pump Switching Strategy to reduce extended stand by conditions

8. Questions ?

9. Cross Sectional Drawing Courtesy of Flowserve Corporation
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10. Pump Wetted Parts (Courtesy of Flowserve Corporation)
Pitting Corrosion in balance line and wear ring
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11. Pump Wetted Parts (Courtesy of Flowserve Corporation)
Stationary wear ring and balance bushing pitting corrosion
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12. (Courtesy of Flowserve Corporation)
Pump Wetted Parts
(Courtesy of Flowserve Corporation)
Stationary wear rings corrosion
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13. (Courtesy of Flowserve Corporation)
Pump Wetted Parts
(Courtesy of Flowserve Corporation)
Pump barrel and wear ring pitting corrosion
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14. (Courtesy of Flowserve Corporation)
Pump Wetted Parts
(Courtesy of Flowserve Corporation)
Pump stuffing box corrosion and diaphragm damage
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15. (Courtesy of Flowserve Corporation)
Pump Wetted Parts
(Courtesy of Flowserve Corporation)
Pump wear ring land area coating damaged
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16. (Courtesy of Flowserve Corporation)
Pump Wetted Parts
(Courtesy of Flowserve Corporation)
Pump wear ring corrosion
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17. (Courtesy of Flowserve Corporation)
Pump Wetted Parts
(Courtesy of Flowserve Corporation)
Stationary wear ring corrosion
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18. (Courtesy of Flowserve Corporation)
Pump shaft at 2nd stage
impeller fit eroded 2
(Courtesy of Flowserve Corporation)
Pump shaft pitting corrosion
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19. Sub-Synchronous Frequency (0
Sub-Synchronous Frequency (0.8X) Waterfall from Aug 5th 2010 to Sep 2nd 2010
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20. Sub-Synchronous Frequency (0
Sub-Synchronous Frequency (0.8X) Waterfall from Aug 5th 2010 to Sep 2nd 2010
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21. Sub-Synchronous Frequency (around 0
Sub-Synchronous Frequency (around 0.8X) Waterfall from January to May 2012
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22. Sub-Synchronous Frequency (around 0
Sub-Synchronous Frequency (around 0.8X) Waterfall from January 5th to May 1st 2012
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23. Vibration overall during the event of
Sub-synchronous frequency (Feb (2012)
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24. After pump Refurbishment and material upgrade
Predominant Frequency 1 X (2012)
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25. After pump Refurbishment and material upgrade
Predominant Frequency 1 X (2012)
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26. After pump Refurbishment overall trend
Since Dec 2012
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27. Thrust bearing axial displacement During the Sub-synchronous Freq.
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