1. Vibration of Rotating Machinery in Hawiyah Gas Plant King Fahd University of Petroleum and Minerals Mechanical Engineering Departments Presented by : Ahmed Al-Jaafari 993714 Advisor : Dr. Meyasser Al-Haddad October 19,2004

2. Outline:  Plant Overview  Hawiyah Gas Plant Processes  Vibration Group  Case Study  Conclusion

3. Hawiyah Gas Plant Overview:  One of the newest plant.  The first completely non-associated gas plant  Completed four months ahead of schedule and under budget  Designed and built from scratch to meet the increased local demand for sales gas

4. Overview: Plant production:  1530 MMSCFD sweet gas  50 MMSCFD sulfur  Increased the Kingdom's gas supply by 30 %.  Increase capacity 2,400 MMSCFD Feed gas of the plant:  Juaf 407 MMSCFD (sweet)  Khuff 1305 MMSCFD (sour)

5. INLET AREA GAS TREAT DEHYDRATION & DEW POINT CONRTOL SALES COMPRESSORS SULFUR RECOVERY Juaf Khuff(Haw) Khuff(Har) 407 MMSCFD 1305 MMSCFD 1225 MMSCFD 50 MMSCFD 1587 MMSCFD 50 MMSCFD USES OF PLANT 1530 MMSCFD SALES GAS HAWIYAH GAS PLANT PROCESSES SCFD = Standard Cubic Feet per Day

6. Maintenance Division Work ShopAreas Maintenance CrewPlanersTechnical Support Unit Quality Assurance Engineers Preventive Maintenance Vibration Group

7. Vibration Group Devices and Software : ADRE System (Automated Diagnosis for Rotating Equipments) C.S.I. Machinery Analyzer (Computational System Incorporated) Data Manager2000 (DM 2000)

8. MOTOR COMPRESSOR Y X A Y A X Y X A X Y A Vibration Readings

9. CASE STUDY Bearing Defect:

10. 1.Ball Pass Frequency of Outer race (BPFO) 2.Ball pass frequency of the Inner race (BPFI) 3.Fundamental Train Frequency (FTF) 4.Ball Spain Frequency (BSF) Bearing Frequencies: BPFO BPFI FTF BSF

11. Bearing Frequencies Calculations RPM = revolutions per minute S = speed, revolutions per second Bd = ball or roller diameter Nb = number of balls or rollers Pd = pitch diameter θ = contact angle 1. Bearing Frequency Equations:

12. 2. Rule of Thumb: Bearing Frequencies Calculations OR = 0.4 x (speed) x N IR = 0.6 x (speed ) x N FTF =0.4 x (speed) Where N is number of balls

13. Bearing Frequencies Calculations 3. Bearing Frequency Calculator:

14. Bearing Frequencies Calculations Example: ( SKF 7311BECBJ)  BPFO = 142.125 Hz  BPFI = 217.85 Hz  FTF = 11.84 Hz  BSF = 52.19 Hz 1. Bearing Frequency Equations: Since: S = 1800 RPM Bd = 0.9474 in Pd = 3.449 in θ = 40 0 Nb = 12 balls  OR = 0.4 (1800/60) 12= 144 Hz  IR = 0.6 (1800/ 60) 12 = 216 Hz  FTF = 0.4 (1800/60) = 12 Hz 2. Rule of Thumb: 3. Bearing Frequency Calculator:  (BPFO) = 146.27Hz  ( BPFI) = 213.73 Hz  (FTF) =12.19 Hz  (BSF) = 59.17 Hz

15. Failure Modes: Zone AZone BZone CZone D Bearing defect frequency region Bearing component natural freq. region Spike energy Stage 1: Stage 2: Stage 3: Stage 4: 5002000 1X 2X 3X Random high freq. Vibration 20-60 kHz

16. Example 1: Bearing Frequency Calculation:  (BPFO) = 146.27Hz  ( BPFI) = 213.73 Hz  (FTF) =12.19 Hz  (BSF) = 59.17 Hz Analysis: Findings: Non- of the bearing frequency match. Highlighted readings are the max. FequencyAccel (G-s) 150.50.04031 236.60.08699 2620.04385 301.10.1609 383.80.8523 443.30.4951 451.70.3171 473.20.07534 486.50.07493 5020.05063 602.20.7262 620.20.2237 637.30.348 6500.3827 661.70.251 736.60.1028 7520.08873 761.40.08081 827.10.1279 856.90.1453

17. Example 1: Zone AZone BZone C Findings: 2 BPFO & 2 BPFI. Bearing natural components freq. Side band freq. around the bearing natural freq. 2 BPFO 2BPFI Natural freq. & Side Band freq. Recommendation: The bearing is defective in the third stage of failure and has to be replaced. Note: harmonic means 1x(freq), 2x(freq), 3x(freq)

18. Replacing the bearing:

19. Example 2:  Inner race defect frequency (BPFI) = 332.6 Hz  Outer race defect frequency (BPFO) = 207.41 Hz  Cage defect frequency (FTF) = 23.05 Hz  Ball spin frequency (BSF) = 122.45 Hz Bearing Frequency Calculation: Analysis: Findings: side-bands freq. around the highest amplitude. the highest amplitude (prime spike vib.) = 6xBPFO

20. Example 2: NoBPFO harmonics 1 2xBPFO414.82 2 3xBPFO622.23 3 4xBPFO829.64 4 5xBPFO1037.05 5 6xBPFO1244.46 6 7xBPFO1451.87 7 8xBPFO1659.28 8 9xBPFO1866.69 9 10xBPFO2074.1 10 11xBPFO2281.51 11 12xBPFO2488.92 12 13xBPFO2696.33 13 14xBPFO2903.74 Frequency Velocity in/sec 415.40.08629 625.70.1474 833.71.222 10422.828 12514.486 14582.298 16672.039 18760.6234 20850.5266 22940.6832 25020.5431 27090.283 29200.2275 Findings: None of the bearing freq. match. The harmonic freq of BPFI do not match. The harmonic freq. of BPFO match with the readings. Recommendation: The bearing outer race is in the third stage of failure and has to be replaced. Note: harmonic means 1x(freq), 2x(freq), 3x(freq)

21. Conclusion: I have been exposed to different types of rotating equipments. I have gained good experience in analyzing the vibration readings and recommend the proper action. I have given the opportunity to work in the Aramco Shadgham shop and dealing with different types of rotating machines during maintenance and overhauling. I have been allowed to make studies and suggestions which improve the performance and reliability of the vibration group.