This slide describe seal gas system in compressor. This Slide is divided into three part: - What is seal gas ? - The function of seal gas? - Description Equipment in Seal gas systems

1. DRY GAS SEAL

2. WHAT IS “ DRY GAS SEAL “ ?
- Gas-lubricated
- Used for twenty years ago
- Almost of the compressor use them

3. THE BENEFIT OF DRY GAS SEAL
- Reduce leakage gas process
- Reduce the complex of system support
- Reduce failure of mechanical system
- Reduce amout of seal oil

4. SEAL GAS SYSTEM

5. WHY USE TANDEM SEAL SYSTEM ?
- There are many seal systems: primary seal gas, secondary
seal gas and separation seal gas
- Prevent process gas leak from secondary seal, allowing
vent to atmosphere
- High safety
DRY GAS SEAL HANDBOOK

6. THE CONFIGURATION OF TANDEM SEAL GAS

7. TANDEM SEAL SYSTEM
• Primary seal : Absorb the pressure drop and vent to
atmosphere
• Secondary seal: as beck-up seal of primary seal gas
• Separation seal : prevent lube oil entering the seal gas
• Barrier Seals : Tách biệt seal gas với shaft bearing, ngăn ngừa
lube oil đi vào gas seal, đồng thời cũng là vách ngăn cuối cùng
khi primary và secondary seal bị phá vỡ
DRY GAS SEAL HANDBOOK

8. YÊU CẦU
• Ap suất lớn hơn áp suất yêu cầu ở điểm kết nối 50 psi
• Không có hạt rắn có kích thuớc lớn hơn 10 micron
• Hạn chế tối thiểu luợng liquid trong khí
• Giữ nhiệt độ cao hơn nhiêt độ dew point tối thiểu 200 F
• Tốc độ dòng seal gas tôi thiểu 32 ft/s
DRY GAS SEAL HANDBOOK API Standard 614

9. DRY SEAL GAS IN DQR ( WET GAS COMPRESSOR )
VENDOR DOCUMENT

12. VENDOR DOCUMENT

14. VENT
• Sử dụng chênh áp xác định độ rò rỉ khí seal
• Dấu hiệu nhận biết leakage: Lưu lựong dòng khí lớn + độ
chênh áp qua orifice lớn
DRY GAS SEAL HANDBOOK

15. DRY GAS SEAL HANDBOOK

16. DRY GAS SEAL HANDBOOK
Warning
PDI > 70 psi
API 614 ( page 71 , 75)
Require
B3 > 75

18. QUESTION AND ANSWER

19. DRY GAS SEAL HANDBOOK
Why flow rate of seal gas is controlled by
different pressure controller ?

20. WHY PRIMARY SEAL GAS IS DRAINER
CONTINUOUSLY WATER BUT THE SECONDARY
SEAL GAS ISN’T ?

21. WHY OUTLET OF PRIMARY SEAL GAS IS VENTED TO
FLARE BUT SECONDARY SEAL GAS IS VENT TO
ATMOSPHERE ?

22. WHY NEED TO HEAT TRANCING WITH ONLY
PRIMARY SEAL GAS ?

23. WITH SECONDARY SEAL GAS, WHY DON’T NEED
TO HAVE A TRIP ALARM ?

24. SUMMARIZE
• Three seal: primary seal, secondary seal and
separation seal
• Requirement on Seal Gas
• Realize problems

25. LINK DOWNLOAD
• DRY GAS SEAL HANDBOOK :
http://tinyurl.com/DRYGASSEAL
• API Standard 614 :
http://tinyurl.com/API614

26. THANK
YOU
FOR
LISTENING

27. DISCUSSION
• When primary seal gas is normal, but
secondary seal gas has problem, what should
we need ?
• Method ?