In 2017, a Mexican urban sewage treatment company had a daily sewage discharge of up to 7 million cubic meters per day due to the increase in urban water use. The existing equipment could no longer meet the city's sewage treatment needs. The factory has undergone comprehensive upgrades, expanded the first and second reservoirs to increase processing capacity, and increased pumping processing capacity. Taking into account many factors of the customer, our company recommended the S-type water conservancy pump to the customer, with a maximum flow rate of 20,000 cubic meters per hour, and a series-parallel design of multiple pumps, which perfectly solved the increasingly difficult sewage treatment scenarios with insufficient discharge capacity.