Considerations for selecting acid-base meters
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There is a current project involving acids and bases (31% HCl, 25% ammonia water, liquid ammonia, etc.), and the entire process makes use of plastic pipes. So, what kind of instruments should be chosen for this application? The instruments required include those for measuring temperature, pressure, liquid level, flow rate, etc. Should corrosion-resistant metals be used, or instruments lined with fluoropolymer material? Does anyone with practical experience have any suggestions? Thank you all first :)
When selecting the outer protective sleeve for temperature instruments, corrosion-resistant metals should be used. For pressure measurement, diaphragm instruments are preferred; the material for the diaphragm can be Hastelloy C, Monel, or fluorinated materials, depending on the type of medium. As for level measurement, it depends on the instrument – some can have a lining while others cannot; this depends on the specific location and the medium being measured. For flow measurement, electromagnetic-type instruments can have a lining, while mass flow meters cannot. . It depends on the specific circumstances to analyze
When choosing a fluorocarbon-lined diaphragm, can 304 material be used?
It is recommended to use a stainless steel sleeve lined with PTFE for the temperature control； For differential pressure or pressure applications, flanged types with membrane made of precious metals (HC) are recommended; a lined membrane can also be chosen depending on the circumstances ； It is recommended to use PTFE lining for the liquid level measurement, in addition to differential pressure ； For flow rate, electromagnetic (lining) is basically used, and the control valve is selected with a lining. The above is only stating the usual situation
Level, temperature, and flow meters can all be lined with fluoropolymer; pressure transmitters can use Monel and Hastelloy C alloys for measurement
Temperature; there are protective tubes made of different materials. Pressure, diaphragm pressure gauges, pressure transmitters with different diaphragms. For liquid level measurement, it can be lined with PTFE, and various other types of level gauges can also be used. For flow rate, PTFE can be used as a lining. There is no absolutely perfect method; only the one that is most suitable for the specific working conditions applies.
Diaphragm 304SS+PTFE is fine… no problem at all. The expert from Building 2 has provided a very authoritative answer… You should click ‘Reply’ on the post, otherwise others won’t be able to see it.