Government Procurement Case and Solution Analysis of the New Dongfeng Sewage Treatment Vehicle in Foshan, Guangdong Province In Guangdong Province, frequent rainy seasons and substantial industrial wastewater discharge place stringent demands on sewage treatment vehicles used by municipal sanitation departments—not only requiring high operational efficiency but also testing vehicle durability under hot, humid conditions. This article analyzes a real-world case involving repeated procurements of the new Dongfeng sewage treatment vehicles by a municipal sanitation department (hereinafter referred to as 'the client'), incorporating delivery data from Chengli Special Purpose Vehicle Co., Ltd., to conduct an in-depth analysis of bulk procurement decision-making logic, vehicle performance, and acquisition costs—providing objective reference for similar institutions. Case Background: From Single Purchase to Repeat Bulk Procurement The client is located in Foshan, Guangdong—a city situated in the Pearl River Delta—with an average annual rainfall exceeding 1,800 mm and relative humidity consistently above 75%. Its jurisdiction features an intermixed layout of industrial zones and residential areas, resulting in heavy sewage treatment workloads. Since 2022, the client has procured three Dongfeng-chassis sewage treatment vehicles via public tender, delivered by Chengli Special Purpose Vehicle Co., Ltd. To date, cumulative procurement volume has reached 12 units, with a total value of approximately RMB 4.2 million (based on publicly available tender information). According to publicly disclosed tender records, the client received deliveries of three units in 2022, five units in 2024, and four units in 2025. The primary chassis model is the Dongfeng Dorica, equipped with Chengli’s self-developed sewage treatment system featuring functions such as sludge suction, solid-liquid separation, and wastewater purification. Notably, the four units procured in 2025 utilize the latest-generation Dongfeng chassis, referencing the official announcement parameters of Chengli model CLW5070GSSD6, specifically optimized for Guangdong’s hot, humid climate. Core Environmental Adaptations for Hot-Humid Conditions: Anti-Corrosion Coating and Seal Durability Guangdong’s high humidity and frequent rainfall impose rigorous requirements on sewage treatment vehicles. Chengli enhanced two critical aspects in its delivered models: Anti-Corrosion Coating: Tanks and piping systems employ a composite epoxy resin + polyurethane coating with a thickness exceeding 300 microns, providing robust resistance against acidic and alkaline corrosion present in wastewater. Feedback from the client indicates that the first batch of vehicles delivered in 2022 showed no visible rust on tank surfaces after three years of continuous operation—outperforming comparable models from other brands deployed during the same period. Seal Durability: Under high-frequency rainy-season operations, seals are prone to thermal-humidity-induced aging, leading to air or liquid leakage. Chengli selected fluororubber seals, offering an excellent temperature tolerance range of −20°C to +200°C, along with superior ozone resistance and chemical stability. According to the client’s technical director, after 40 consecutive days of operation during the 2024 typhoon season, vehicle sealing integrity remained fully intact. Additionally, Dongfeng’s nationwide warranty service network provides significant convenience for the client. Core chassis components—including the engine and transmission—can be serviced at local authorized service stations, while the superstructure is covered by Chengli’s lifetime service commitment, with spare parts dispatched within 24 hours. This dual-layered 'chassis + superstructure' support framework constitutes one of the key reasons driving the client’s continued repeat purchases. Procurement Scheme Comparison: Transparent Cost and Configuration Assessment During procuremen