What material should be used for storage tanks containing around 8% sodium hypochlorite?
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This post was last edited by qldch2306 on 2016-1-22 at 21:08. What material should be used for storage tanks containing around 8% sodium hypochlorite under normal temperature and pressure conditions? Is PVC+FRP really viable? According to Mr. Zuo Jingyi’s corrosion data and material selection guide, PVC can be used; PP is suitable at 20 degrees, but should be used with caution above 50 degrees, depending on the formula. However, according to the data in Appendix A of the HG20640-1997 standard, there is no information on the corrosion resistance of rigid PVC, while modified PP shows corrosion resistance at temperatures ranging from 20 to 60 degrees. (Table A.2) I’m not sure how to choose the materials now; please give me some advice, experts. Thank you. Economic considerations also need to be taken into account when selecting materials. Someone once suggested that I use lead cans. . .
If it is to be used for a long time, use titanium material directly. Additionally, CPVC and PTFE materials can definitely be used as well. Care should be taken with PP material, as free chlorine has a certain effect on polyolefins.
Hello, qugd! Thank you for the advice! ! It’s a atmospheric pressure storage tank of large size, DN9000×12000; I prefer to use a CPVC lining with FRP reinforcement wrapped on the outside (please evaluate whether this is appropriate). It’s not clear by how much more expensive perfluoro and titanium materials will be compared to rigid PVC; after all, cost is something that homeowners must take into consideration – it’s all about money!
The price of tetrafluoroethylene is estimated to be twice as much, while that of titanium is nearly three times as much. In terms of cost-effectiveness, CPVC-covered fiberglass offers better value.! Of course, this depends on whether the temperature and pressure are appropriate, as well as the location; feel free to communicate more if you have the chance at QQ77390271
This post was last edited by Cuaji Yisu on 2016-1-23 at 10:41. Recommended for normal temperature and pressure conditions: 304 stainless steel storage tank blanks; the price of stainless steel is currently very low. Use PO or PE internally for cost-effectiveness.
The problem with PVC is that its expansion and contraction cannot keep pace with those of FRP, which may lead to cracking and brittle failure of PVC. We are in the north, in the Shandong region. It will be better in the south. Modified CPVC might be better, but there are still risks of thermal expansion and contraction in this regard. The one lined with PTFE should work. After all, PTFE is softer, but it’s more expensive. Personally, I am reluctant to approve the use of A-grade stainless steel or titanium, as sodium hypochlorite solutions contain Cl- ions, and I am concerned that this could lead to additional problems. Anyway, I have no idea anymore; it’s painful :L
For the dimensions of DN9000×12000, with a volume of over 100 cubic meters, you can calculate the costs of carbon steel and stainless steel by yourself. The stainless steel should be 12 millimeters thick or more.
Well, the capacity of this tank is over 700 cubic meters. Carbon steel can’t be more expensive than stainless steel, right? And what is the purpose of using stainless steel? Is it used as a strength layer or an anti-corrosion layer? Since the anti-corrosion layer serves as a lining, wouldn’t it be better to use carbon steel such as Q345R for the strength layer of the outer wall? You know that carbon steel is stronger than stainless steel; its wall thickness can be thinner, making it more economical.
I’m not sure, and I haven’t considered using stainless steel composite panels. If stainless steel or titanium is to be used, composite panels can be an option; after all, both stainless steel composite panels and titanium composite panels are much cheaper than single-layer panels.
Glass fiber reinforced plastic wrapped around the Cl-PCV is sufficient.