3 months ago

African Petrochemicals Edition_16.2

  • Text
  • Edition
  • Applications
  • Industrial
  • Thyssenkrupp
  • Lubrication
  • Sealing
  • Engen
  • Products
  • Solutions
  • Refinery
  • Valves


ZWICK FOR MOLTEN SULPHUR OR SULPHUR TAIL GAS If you work with Molten Sulphur or Sulphur Tail gas, please take time to read more. Design engineers at Zwick in Germany have looked at solving on-going problems being experienced with valves on sulphur units. Typical valve problems on large bore line sizes range from seizing of the packing to severe seat damage when valve need to be operated after long periods of time of inactivity. Valves should be specified as steam jacketed valves as this is a standard mandatory type of valve requirement. Generally a standard valve may be suitable in an ideal line were there are never any shutdowns or upset conditions as once the valves body temperature has reached that of the hot sulphur or tail gas passing through it will not allow for any solidification, however in an upset condition were the valve body cools down with sulphur cooling also, then this will solidify in the bearing / shaft areas which will consequently generate a seizure of these elements. Based on international experience, Zwick engineers recommend the use of steam jacketed valves as these would maintain the critical areas under a constant temperature, thus eliminating any potential seizure. Zwick are capable of supplying valves in both wafer and double flanged style with steam jackets, and we can also apply a steam traced trim (stem and disc). Zwick Tri-Con series valves come with bearing protectors, which reduce the ingress of the medium into the critical areas, which coupled with the bearing flush purge ports constitute a true cleansing and protection of these critical areas. The following explanation highlights the technical differences between the Zwick Tri-Con valve and other manufacturers of valves ranging from double eccentric to unjacketed valves which will fail in this type of application. The Zwick Tri-Con series valve is a specially designed process isolation, on/ off and control valve, which has a wide range of application uses limited only by that of the actual materials used, in fact Zwick manufacture valves for applications which range from -196ºC up to +815ºC. Valves can be manufactured in any machinable form of alloy available on the market for specific client requirements. The Zwick Tri-Con series valve is a triple offset valve with true cone in cone design which totally eliminates any rubbing of the seats, hence eliminates any wear and tear which would generate leakages across the seat, this is technically not possible for other typical high performance valves, which means it is limited to a double eccentric design, rubbing sealing in the last 15- 18º which will generate leakage as the time goes by. 22 The other standard double eccentric are not designed for these severe applications therefore any attempt to use it for particular process applications may result in a problematic outcome. Self Centering disc With it’s unique self centering temperature compensating disc, the Tri-Con series construction guarantees the optimal position of the laminated seal against the seat. Jamming due to thermal expansion is therefore eliminated. The torque transmission with keys The disc is keyed to the shaft and not pinned, providing equal torque transmission and eliminating the danger of pins sheering off. Ideal lamination and disc design The strong disc with it’s elliptical supporting surface offers the best fixing of the lamination. The zero leakage is achieved by the special machining of thre lamination. Supporting bearing bushing The optimal position of the bearing reduces the bending of the shaft. This guarantees bi-directional tightness under maximum pressure. General characteristics • Triple eccentric design • Metal seating • Zero leakage • Pressure classes • Full bi-directional shutoff tp API & DIN, ZERO Leakage • Temperature range -196ºC up to +815ºC • Size range 2” to 72” (DN50 to DN1800) • Friction free opening and closing • Vacuum tight • Laminated seal and seat made of stainless steel • Anti blow-out shaft to API 609 • Steel casting, stainless steel and special alloys • Fire-safe acc. To BD 6755 and API 607 for both flow directions • Fugitive emission control acc. To “TA-Luft II” Valve & Automation are the agents for Zwick products. Please contact Desmond Delport on 011 397 2833 or

Roadshows to look out for in 2020… • Secunda Petrochemicals IPP & Renewables Roadshow • Sasolburg Petrochemicals IPP & Renewables Roadshow • EPC, IPP & Renewables Roadshow • Durban Petrochemical IPP & Renewables Roadshow • Germiston Everything Industrial Roadshow • The Mossel Bay Petrochemical Roadshow Visit our website or join us on social media for updates on the Roadshows Bookings are now opened. Find out more about our early bird specials • 011 083 5125 / 084 894 9800 • ANOTHER 68 SOUTH DURBANITES GRADUATE FROM ENGEN’S COMPUTER SCHOOL The Engen Computer School in Wentworth held a graduation ceremony on 5 September where 68 proud community members received certificates for completing an End User computing course. Over the past decade, Engen’s free computer skills training school has transformed many lives in South Durban, boosting graduates’ prospects of finding employment. “Including yesterday’s graduates, just over 2000 students have graduated to date, each of them gaining the knowledge and confidence to go out and seek jobs that would otherwise never have been possible,” says Sheryl Casalis, training director of Added Advantage Academy. The Engen Computer School offers South Durban residents introductory-level computer skills training, covering eight units of the National Certificate: Information Technology, End User Computing qualification. To enrol, applicants must be unemployed school-leavers and reside in South Durban. While matric and age criteria are not prescribed, most students who attend the school are aged from 20 to 40. According to Casalis, three four-month courses are offered per annum, each accommodating 80 people. Engen invests Proud graduates of the Engen Computer School. approximately R15 000 per student to attend the course. “The competency rate for students is between 94% and 99% by the time they complete the course,” adds Casalis. “Upon graduation they are computer literate individuals able to work independently using the most common computer programmes utilised in offices today.” The third course for 2019 commenced on 26 August and has 78 attendees. Engen’s head of Transformation and Stakeholder Engagement, Unathi Magida, says the Engen Computer Centre is well known in South Durban and almost always has a waiting list of people wanting to upskill themselves. Magida says Engen is both proud and humbled to play a small role in positively changing lives of South Durban community members, who reside in an area where the Engen Refinery is located. “With poverty and unemployment rife in South Africa, Engen is cognisant of the fact that the government cannot be relied on to provide solutions alone,” says Magida. “As such, we are committed to stepping up and doing the right thing, starting with paying special attention to the people in the communities in which we operate,” she adds. For more information, please contact: Gavin Smith, Engen External Communications Manager Tel: +27 21 403 4312 23


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