Cumene, the common name for isopropylbenzene, is an aromatic hydrocarbon and a colorless liquid under atmospheric conditions with a characteristic smell. It is a component of crude oil and refined fuels and is mainly used in the production of phenol.
Ineos in Gladbeck and Degussa in Marl, both located in Germany, are supplied with cumene by a pipeline. The pump station for this pipeline is situated inside the chemical industry park in Marl and is operated by Degussa Infracor. Cumene is classified as hazardous to the environment, so the “TA-Luft” directive (German Clean Air Directive) has to be considered for any sealing solution.
Originally, the pump was equipped with a Flowserve mechanical seal type EUROPAC 613/663 in tandem arrangement. With this seal, the required maximum temperature of the supply medium of 104˚F (40°C) was always exceeded and the seal was continuously squeaking during operation.
Operating temperature: 41˚F – 122˚F (5 – 50˚C)
Operating pressure at seal: 17.4 – 34.8 psi (1.2 – 2.4 barg)
Pump: Centrifugal pump, type MC 80-260/62
Pump manufacturer: Sulzer
Speed: 2,975 rpm
Seals include materials: H75VN/80-FTA5, AQ1KMG – AQ1KMG
Mode of operation: Plan 11 and Plan 52 according to API 682
Supply system: TS 2000/M051-A1, operation under atmospheric pressure
The EagleBurgmann Solution
The critical points of this application are the poor lubrication properties and the low heat capacity of the process medium. The engineered EagleBurgmann H75N mechanical dual seal in tandem arrangement was selected and retrofitted to the pump.
Technical features of the EagleBurgmann H75VN seal:
• Cartridge unit, easy to install
• Certified according to API 682/ISO 21049 for the application in flashing hydrocarbons. Meets the requirements for low emission seals based on STLE-limit values
• Counter-rotating pumping screw to support the circulation of the buffer medium to ensure an optimal cooling and lubrication of the mechanical seal
• Plan 11 and 52 with multi-point injection: the buffer medium is divided into several sub-currents that are directed towards the sliding face at relatively high flow velocities, improving heat removal from the mechanical seal
• Self-closing: the seal will remain closed and will keep the full functionality even in situations of pressure reversal or failure of the supply system
• Perfluoroelastomers due to the chemical resistance
The EagleBurgmann H75VN meets all requirements of the operator regarding the maximum buffer fluid temperature of 104˚F (40°C), and the squeaking of the seal was eliminated. The mechanical seals have been successfully in operation since the beginning of 2006 and have been running to the full satisfaction of the customer, with further pumps retrofitted currently. Additionally, the EagleBurgmann H75VN mechanical seal is now specified as standard for pipeline pumps.
For more information on the H75VN or its use in pipeline pumps, contact us at email@example.com.