The pump of the first tank must be an acid-resistant pump. If it is not acid-resistant, you can change your prosess by only replacing the pump with an acid-resistant one.
It is determined according to the surface of the materials passing through the system. For example, it is recommended to increase the temperature for more effective cleaning of rusty, slag materials. Temperature can be increased up to 40 ˚C. Temperatures above 40 ˚C may cause corrosive effects.
No. No foam problems when working cold.