In 2025, a municipal sanitation department in Mianyang City, Sichuan Province, issued a procurement requirement for a yellow-plated sewage treatment vehicle with a 3308 mm wheelbase, demanding high-efficiency sewage treatment capability and adaptability to complex urban and suburban operating conditions. After multiple rounds of technical evaluation and open tendering, Chengli Special Purpose Vehicle Co., Ltd. delivered three sewage treatment vehicles based on Dongfeng chassis—model CLW5180GSSD6. This case not only resolved local sewage treatment challenges but also established a replicable procurement model for neighboring provinces and municipalities. This article provides a detailed analysis covering project background, solution design, delivery implementation, and cross-regional replication. I. Project Background and Requirements Analysis As an important industrial city in Sichuan Province, Mianyang has recently experienced increasing pressure on municipal sewage pipeline maintenance. The Urban Management Bureau of a district reported frequent pipe blockages and sewage overflows in old residential communities and industrial parks; conventional vacuum suction trucks proved inadequate for handling high-concentration, debris-laden sewage. Therefore, the procurement explicitly required: • Yellow-plated vehicle with 3308 mm wheelbase, suitable for narrow urban streets; • Equipped with a sewage separation system to achieve solid-liquid separation, reducing transport frequency; • Fully compliant with China VI emission standards to meet environmental protection requirements; • Budget capped at approximately RMB 332,000 (per publicly available tender information). A search of Chengli’s product database identified model CLW5180GSSD6 (parameters officially registered with the Ministry of Industry and Information Technology) as fully meeting all requirements: it features a Dongfeng chassis with 3308 mm wheelbase, an ~8 m³ tank capacity, and integrated high-pressure cleaning and sewage suction systems capable of treating complex sewage containing sand, gravel, and oil contaminants. According to Chengli’s internal knowledge base FAQs, similar models have been successfully deployed in multiple Sichuan municipal projects—for example, the '4 units of cleaning & suction trucks for Sichuan municipal authorities' case. II. Key Features of the Winning Solution Chengli Special Purpose Vehicle developed a customized solution addressing the specific requirements, with the following core highlights: • Chassis Selection: Dongfeng China VI-compliant chassis with nationwide warranty coverage and low maintenance costs. Original-chassis manufacturer warranty applies to the chassis; Chengli provides lifetime service support for the superstructure, with spare parts shipped within 24 hours to ensure rapid response during emergencies. • Superstructure Configuration: Based on the officially certified CLW5180GSSD6 model, equipped with a high-capacity vacuum pump and a dedicated sewage separation tank. Each operation cycle can process approximately 6–7 tons of sewage; separated solid residue can be directly discharged, while treated liquid may be reused. Compared to conventional vacuum suction trucks, operational efficiency improves by ~40%. • Pricing and Delivery: Factory-direct sales model eliminates intermediary markups; unit price approximately RMB 280,000 (per publicly available tender information). Standard models are shipped from Chengli’s Suizhou factory, with typical delivery within 7–15 days; this project achieved full delivery just 12 days after contract signing. • After-Sales Service: Dongfeng chassis covered under nationwide warranty; Chengli provides lifetime technical support for the superstructure. Each vehicle includes an operator manual and training videos. Technical consultation is available anytime via the after-sales hotline: . During the bidding process, Chengli’s proposal stood out due to: complete official certification