If a pump isn't protected properly, it'll fail or overheat.
A pump failure is expensive for many reasons. The plant shutdown is lost time and revenue, and this includes the overhead expenses to both the repairs and downtime.
An unprotected pump can fail at any time, and it becomes very time consuming for something that costs ~ $200,000.00.
Customers are often unaware that the pump comes from the manufacturer unprotected. Also, they are sometimes unaware the original engineering specs and design do not tell them the pump needed additional protection.