BenJohnson,
Yes the RO plant design is sophisticated but as a mechanical engineer the different apsects should have been encountered if you have 15 to 20 years experience in the petrochem industry.
The hydraulics and pump selection are no more different than for a refinery or chemical process plant.
The use of super duplex or duplex stainless steels, thermoplastic piping is no different to other process industries.
Waste treatment and solids recovery along with chemical treatment is no different.
The biggest hurdle is that engineers think that an RO plant is a water treatment plant. This is far from the truth. To be honest, water industry engineers are left floundering as they just do not have the experience of ASME B31.3 , Class 600/900 flanged pipe systems, welding special ss alloys, high pressure pumping in parallel operation, high pressure filtration, brine handling etc etc. These plants are sophisticatedd chemical process plants. The
only thing to do with the water industry is the end product.
I worked on a major desalination project where the consultant put their water industry engineers on the job rather than their chemical enginering specialists. What a disaster. It will end up in the courts as they just "didn't know what they didnt know". Designs ran late, there was a steep learning curve and it cost a lot of extra money to build.
I have seen the same thing happen in the mining industry where solvent extraction and hogh pressure acid recovery of nickel was involved. This was not a mining project or mineral recovery project. It was a chemical processsing plant admittedly with solids handling.
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King