What tank internal coating material would you recommend if tank operating temperature is higher than 100 C. This is waste water tank with high chloride content.
One that has both a satisfactory qualification test report (preferably independent from the coating manufacturer)and a verifiable track record. A mixture of NORSOK M-501 and NACE TM0174 would make a good qualification test regime.
Note that short and long term coating behaviour in severe conditions can be simulated and analyzed using CheFEM (Chemical interaction driven FEM analysis of advanced materials). This will allow more systematic and completely independent evualuation of polymer based coating materials (including eventual required reinforcements).