Selection of diaphragm for differential pressure transmitter in 60% concentration NaOH solution
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Dear sea friends, for a differential pressure transmitter operating with 60% concentrated NaOH at atmospheric pressure and a temperature of 163 degrees, would a 316L diaphragm coated with gold-rhodium be suitable? Pretty urgent
Is it going to sink? Could the experts here at Haiyou please help solve this?
I agree with Pig Brother. After checking, for this concentration and temperature, using a platinum diaphragm is the most stable option... I’m not very familiar with coatings; I’ll wait for experts to explain it
If the temperature is not high, use 316L; if the temperature exceeds 100, use Hastelloy C or Monel! :lol
Ha C-276 with PTFE coating, steel-to-steel
At a temperature of 163 degrees, it probably won’t work; 40% NaOH at over 100 degrees would likely make the diaphragm unstable. And this is a 60% concentration – Monel may hold up in the short term, but it’s unclear what will happen with long-term use
Isn’t it more economical and practical to use 316L with a PTFE coating in this case?
For titanium alloys, this concentration can reach 130° or 160°; I’m not sure though as there are no relevant data available. Nickel-molybdenum-chromium-iron alloys or iron coated with nickel might also work, but the concentration and temperature in your case are too high, and there’s no practical data to support it
We have 50%, 165-degree membrane nickel – no problem
200 alloy (99Ni), temperature resistance up to 350℃