Selection issues for propylene storage tanks and transfer pipelines
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This post was last edited by beileim1 on 2009-6-16 at 12:29. For the recovery of propylene in current production, what kind of pipes and receiving tanks are best to use, and what material should they be made of? Some people say that CS is enough; SS is not necessary as it’s more expensive. I’m not sure which one to choose Is there something else that would be more suitable?
In the recycling system, we generally use SS material, mainly due to the need for high cleanliness of the materials. It is also used to produce pharmaceutical intermediates, and compared to CS, SS offers higher safety levels. The receiving tanks are also made of SS. When considering the material choice, it is necessary to take into account the properties of the auxiliary materials as well; not all of the materials recovered are necessarily propylene-based. Additionally, attention must be paid to static electricity issues in this recycling system, and the flow rate of the materials needs to be controlled.
Carbon steel is sufficient; there’s no need to waste it
For pure propylene, carbon steel CS is sufficient; there will be no corrosion issues. We have been using it for over 10 years with no problems. If you are dealing with recycled propylene, it’s necessary to check what other components are present in it. If it contains only water, then CS is still an appropriate choice. However, if the propylene contains oxidation products such as propionic acid, acetic acid, or other corrosive impurities, caution is needed. In cases where the concentration of such substances is high, SS stainless steel should be used instead.
There is no problem in using carbon steel equipment and pipelines for storing and transporting propylene. It should be noted with special attention that plastic pipes must not be used; when plastic pipes are used for transportation, static electricity accumulates regardless of the flow rate, and since this electricity cannot be discharged, it easily leads to fires. Even when using carbon steel pipes for transportation, anti-static bonding copper strips should be used between the flanges, and the grounding of the equipment must be checked regularly to ensure that the resistance is less than 2 ohms. For long-distance transportation of propylene, an electrostatic ground should be installed every 200 meters.
Thank you all. It seems that I still need to address the issue of pipeline flow velocity in order to prevent static electricity. I think CS will be sufficient for this purpose, as the pH is slightly alkaline
I have seen manufacturers use carbon steel pipes lined with polyethylene or PTFE.
Considering cost-effectiveness, it is recommended to use CS
What are the typical flow rates before and after the Bingtong pump?
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