Procurement case of a municipal sanitation department in Guiyang: Full-range supply solution for Dongfeng 3308 mm wheelbase, National VI-compliant sewage treatment vehicles. In Southwest China—especially in Guiyang, characterized by abundant rainfall and high humidity—the procurement requirements for sewage treatment vehicles by municipal sanitation departments are particularly stringent. Recently, a municipal sanitation department procured a batch of National VI sewage treatment vehicles built on the Dongfeng 3308 mm wheelbase chassis through public tender. In this procurement project, Chengli Special Purpose Vehicle Co., Ltd. not only supplied the core upper structures for sewage treatment vehicles but also coordinated the provision of supporting sanitation equipment—including water-sprinkling trucks and vacuum suction trucks—achieving one-stop, multi-category supply. According to feedback from the department, the primary reason for selecting Chengli Special Purpose Vehicle was its capability to meet requirements across multiple vehicle types, effectively reducing procurement and management costs; furthermore, the upper-structure components were specifically reinforced to withstand Guiyang’s high-humidity and rainy climate conditions. Project Background and Requirements Analysis The municipal sanitation department is primarily responsible for maintenance of urban and some rural sewage networks, emergency pumping and drainage, and environmental remediation. Due to Guiyang’s prolonged rainy season and consequent surge in underground pipeline wastewater volume, conventional single-function vehicles struggle to meet complex operational demands. The core procurement item was the Dongfeng 3308 mm wheelbase sewage treatment vehicle, whose compact chassis is well-suited for narrow alleys and urban roads. Concurrently, the department also procured 3-cubic-meter vacuum suction trucks and 8-cubic-meter water-sprinkling trucks to support post-sewage cleanup road washing operations. According to publicly released tender information, the total project budget was controlled within approximately RMB 2.2 million, with the unit price of the Dongfeng 3308 mm wheelbase sewage treatment vehicle around RMB 250,000 (based on local procurement conventions). Leveraging its full-range supply capability and customized solutions tailored for humid, hot environments, Chengli Special Purpose Vehicle successfully delivered these vehicles. Core Vehicle Model: Dongfeng 3308 mm Wheelbase, National VI Sewage Treatment Vehicle Upper Structure Solution The delivered sewage treatment vehicles feature the Dongfeng 3308 mm wheelbase chassis equipped with a National VI emission-compliant engine, meeting Guiyang’s strict environmental protection requirements. The upper structure—designed and manufactured by Chengli Special Purpose Vehicle—features the following key characteristics: Enhanced Anti-Corrosion Coating: To address Guiyang’s high humidity and strong acid-rain corrosion, the entire tank body and piping system employ Chengli’s proprietary dual-layer anti-corrosion coating process—epoxy zinc-rich primer combined with polyurethane weather-resistant topcoat—significantly improving corrosion resistance. Seal Durability for Humid-Hot Environments: All hydraulic cylinders, water pumps, and valve seals have been upgraded to high-temperature- and humidity-resistant rubber materials, ensuring no premature aging or leakage under prolonged operation in hot, humid conditions. High-Load Operational Capability: Designed for increased wastewater volume and frequent continuous operation during the rainy season, this model is equipped with a higher-power sewage pump and an optimized filtration system, enabling over eight hours of uninterrupted high-load operation. The official model number for this vehicle is CLW5070GSSD6 (referencing MIIT certification parameters), belonging to Chengli Special Purpose Vehicle’s mature product line, fully compliant for registration an