Phosphoric acid is a moderately strong inorganic acid of a reducing nature with a SG of 1.9. Material selection is critical when selecting a pump as many metals are adversely effected by phosphoric acid.
While some metals can be used in the construction of phosphoric acid pumps they may have a limited life. The best metals to use would be either 316 stainless steel or Hastelloy. Technopolymers offer good chemical resistance; materials such as polypropylene, PVDF and ETFE, are recommended. Viton and PTFE are the most resistant elastomers.
AxFlow offer a range of chemically resistant pumps that includes magnetically driven pumps and lined pumps all suitable for pumping phosphoric acid that range from plastic AODD pumps including numerous different types of mag drive pump.