NBF and NBH are pump sets assembled by vertical multistage pumps and high-pressure pumps in serial, capable of generating a pressure of 48 bar. Each pump set consists of two pumps, both of which are non-self-priming vertical multistage centrifugal pumps. The motor shaft is coupled to the pump shaft via a coupling mounted on a bracket, and tie rod bolts secure the pressure-resistant cylinder and flow parts between the bracket and the water chamber. The pump inlet is aligned with the bottom of the pump. NBF is a stainless steel vertical multistage centrifugal pump; NBH is a high-pressure pump with an internal reverse-core structure, which reduces the pressure requirements on external components and seals. The pump sets feature high efficiency and energy saving, high lift, simple structure, and high reliability. Both use modular mechanical seals with a detachable structure, making maintenance and repair convenient and quick.