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Seal for high-pressure liquid chromatography devices
PATENTS The test work and industrial experience to date have not answered all the questions. The optimum use of the vortex flow to improve heat transfer and removal of both gas and solids requires some optimization. The relatively steep taper that provides many of the benefits of heat transfer and gas removal requires some form of vortex modifier. The provision of this modifier – without losing many of the benefits – would appear to be worthy of further investigation. The computer modeling required is quite intensive. However, it would permit the investigation of a range of design options to select an optimum compromise that could then be tested experimentally. We have also seen that the overall pump design and type of impeller are important factors, so these must also be included in any such evaluation. The potential benefits of reduced cost of seal installation, improved reliability and energy savings appear to be well worth further attention by all concerned, whether seal suppliers, pump manufacturers or end-users.
References 1. The environment of a mechanical seal. John Crane.
2. J.M. Heald: The seal’s environment – its housing. 7th International Conference on Fluid Sealing, BHRA, 1975. 3. 905 ISO process pumps. Weir Clear Liquid Division. 4. T. Evans, J. Finley and K. Kayler: Ethanol plant overcomes maintenance problems using Goulds TaperBore and John Crane flushless seal (2003). 5. B. Ng: Pump applications in pulp & paper; sulphate process; recausticizing plant. 6. Engineered seal chambers selection guide. Goulds Pumps. 7. N.D. Barnes et al.: Mechanical seal housing optimisation study. BHR Group Report CR3005, 1988. 8. N.D. Barnes et al.: Mechanical seal housing optimisation study. BHR Group Report CR6125, 1992. 9. M. Williams and N.D. Barnes: Flow visualisation experiments on housing grade 2 (ISO 3069 Revision). BHR Group Report CR6196, 1993. 10. M. Williams et al.: Seal housing design evaluation. BHR Group Report CR 6378, 1995. 11. H. Azibert and R. Clark: Using CFD to improve performance and extend life of
mechanical seals in slurry applications. 17th International Conference on Fluid Sealing, BHR Group, 2003. 12. J. Fleming: New generation water pump range offers operators a high return investment. Weir Clear Liquid Division, 2003. 13. N.D. Barnes et al.: Slurry seal investigation. BHR Group Report CR6376, 1994. 14. J. Dunford: Seal protection: guarding against air and abrasives. Enviroseal Engineering Products Ltd, 1995. 15. ISO 3069-2000, End-suction centrifugal pumps. Dimensions of cavities for mechanical seals and for soft packing. International Standards Organization, 2004. 16. ISO 21049-2004, Pumps – Shaft sealing systems for centrifugal and rotary pumps. International Standards Organization, 2004. 17. C. Fone: International seal standards – do they affect us? Sealing Technology (August 2003) 8–10. 18. API 682, Pumps – Shaft sealing systems for centrifugal and rotary pumps. American Petroleum Institute, 2002. 19. ANSI B73.1, Specification for horizontal end suction centrifugal pumps for chemical process. American National Standards Institute, 2001.
Patents Surgical catheter head with closing seal element Applicant: Disetronic Licensing AG, Switzerland This invention relates to a catheter head for medical and pharmaceutical applications. A base body can be positioned on organic tissue. The connecting body (20) serves as the fluid connector for the base body. A fluid channel (23) forms the fluid connection. A seal (11) is retained by
the housing, and comprises a connector face by which the fluid is channeled to the cannula (10), and a closing element (13). This can be displaced relative to the sealing element to open and close the fluid channel. Patent number: WO 2004/050148 Inventors: M. Bütikofer, R. Zihlmann and S. Scheurer Publication date: 17 June 2004
The catheter head described in WO 2004/050148, showing the closing seal element (11).
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Seal for high-pressure liquid chromatography devices Applicant: Dionex Corp., USA This patent is particularly concerned with seals for high-pressure liquid chromatography. In priorart designs (below, left) the energizing O-ring is exposed to the pumped fluid, including solvents and other chemicals that may degrade the FKM material. The replacement design (below, right)
includes a flared portion on the plastic component of the seal that fully encases the O-ring, to protect it from contact with the pumped fluid. The retaining flange on the plastic component is also described in the patent. Patent number: WO 2004/048823 Inventor: G.N. Proper Publication date: 10 June 2004
Side view of seal mounted in pump head of high-pressure pump, with prior art on the left and the seal described in WO 2004/048823 on the right.
Sealing Technology September 2004
References 1. The environment of a mechanical seal. John Crane.
2. J.M. Heald: The seal’s environment – its housing. 7th International Conference on Fluid Sealing, BHRA, 1975. 3. 905 ISO process pumps. Weir Clear Liquid Division. 4. T. Evans, J. Finley and K. Kayler: Ethanol plant overcomes maintenance problems using Goulds TaperBore and John Crane flushless seal (2003). 5. B. Ng: Pump applications in pulp & paper; sulphate process; recausticizing plant. 6. Engineered seal chambers selection guide. Goulds Pumps. 7. N.D. Barnes et al.: Mechanical seal housing optimisation study. BHR Group Report CR3005, 1988. 8. N.D. Barnes et al.: Mechanical seal housing optimisation study. BHR Group Report CR6125, 1992. 9. M. Williams and N.D. Barnes: Flow visualisation experiments on housing grade 2 (ISO 3069 Revision). BHR Group Report CR6196, 1993. 10. M. Williams et al.: Seal housing design evaluation. BHR Group Report CR 6378, 1995. 11. H. Azibert and R. Clark: Using CFD to improve performance and extend life of
mechanical seals in slurry applications. 17th International Conference on Fluid Sealing, BHR Group, 2003. 12. J. Fleming: New generation water pump range offers operators a high return investment. Weir Clear Liquid Division, 2003. 13. N.D. Barnes et al.: Slurry seal investigation. BHR Group Report CR6376, 1994. 14. J. Dunford: Seal protection: guarding against air and abrasives. Enviroseal Engineering Products Ltd, 1995. 15. ISO 3069-2000, End-suction centrifugal pumps. Dimensions of cavities for mechanical seals and for soft packing. International Standards Organization, 2004. 16. ISO 21049-2004, Pumps – Shaft sealing systems for centrifugal and rotary pumps. International Standards Organization, 2004. 17. C. Fone: International seal standards – do they affect us? Sealing Technology (August 2003) 8–10. 18. API 682, Pumps – Shaft sealing systems for centrifugal and rotary pumps. American Petroleum Institute, 2002. 19. ANSI B73.1, Specification for horizontal end suction centrifugal pumps for chemical process. American National Standards Institute, 2001.
Patents Surgical catheter head with closing seal element Applicant: Disetronic Licensing AG, Switzerland This invention relates to a catheter head for medical and pharmaceutical applications. A base body can be positioned on organic tissue. The connecting body (20) serves as the fluid connector for the base body. A fluid channel (23) forms the fluid connection. A seal (11) is retained by
the housing, and comprises a connector face by which the fluid is channeled to the cannula (10), and a closing element (13). This can be displaced relative to the sealing element to open and close the fluid channel. Patent number: WO 2004/050148 Inventors: M. Bütikofer, R. Zihlmann and S. Scheurer Publication date: 17 June 2004
The catheter head described in WO 2004/050148, showing the closing seal element (11).
14
Seal for high-pressure liquid chromatography devices Applicant: Dionex Corp., USA This patent is particularly concerned with seals for high-pressure liquid chromatography. In priorart designs (below, left) the energizing O-ring is exposed to the pumped fluid, including solvents and other chemicals that may degrade the FKM material. The replacement design (below, right)
includes a flared portion on the plastic component of the seal that fully encases the O-ring, to protect it from contact with the pumped fluid. The retaining flange on the plastic component is also described in the patent. Patent number: WO 2004/048823 Inventor: G.N. Proper Publication date: 10 June 2004
Side view of seal mounted in pump head of high-pressure pump, with prior art on the left and the seal described in WO 2004/048823 on the right.
Sealing Technology September 2004