Plastic bottles made from PET and polyester clothes are a part of our everyday lives. Both are made from the basic chemical terephthalic acid. A demanding oxidation process requiring ever-fresh air is used in the production of Purified Terephthalic Acid, commonly referred to as PTA. A PTA machine train consists of a steam turbine, a gear transmission compressor for ambient air, an off-gas expander and a motor-generator. Caused by an exothermic reaction in the process, a large amount of steam is created, which among other things, is used to drive the turbine.
Due to this demanding oxidation process, quick-closing valves need to safely shut off the steam flow in less than one second to limit the speed upward in the case of a turbine trip. Since this is such a critical valve application, high demands are placed on all the materials and instrumentation. All of the installed butterfly valves must also help minimize energy loss as much as possible.
Neles BW series valves, which have also been delivered to the Siemens PTA project, can be installed in pipelines with flanges according to all required industry standards. Due to their higher than industry average Cv values, Neles valves offer significant benefits in this application. Our nominal sizes can often be up to 4” - 12” smaller than those of many other valves, helping you achieve substantial savings in terms of costs. Also, the unique sealing system allows these valves to be used even with a supercritical pressure ratio. These features among others have helped the
Siemens PTA project and plant facility in Rotterdam successfully and cost-efficiently meet even the strictest requirements for a modern PTA plant.
Read more about this in the article Fulfilling the stringent requirements at PTA plants.
Text written by Martin Dressen.
This blog post has been up-dated in July 2020, due to company name change to Neles.