Case Study and Bid Solution Analysis: Chongqing Dongfeng D6 Sewage Treatment Vehicle (Blue License Plate) Government Procurement In Chongqing—a mountainous metropolis—municipal sanitation departments confront distinctive challenges: hilly topography, hot-humid climate, and prolonged rainy seasons. These factors place stringent requirements on the durability and operational efficiency of sewage treatment vehicles. Recently, a municipal sanitation department, responding to maintenance needs for aging sewer networks within its jurisdiction, publicly procured two Dongfeng D6 blue-plate sewage treatment vehicles. This case study, grounded in authentic procurement data, offers an in-depth analysis of the equipment selection logic and winning bid solution—aimed at helping procurement units nationwide avoid common pitfalls. Case Background: Selection Pain Points in Hot-Humid Environments The procuring entity was the Urban Management Bureau of a district in Chongqing, responsible for routine cleaning and emergency response across approximately 30 km of aging sewer pipelines. Summer temperatures average 38°C, relative humidity consistently exceeds 80%, and the rainy season lasts four months annually. Previously deployed older models frequently suffered from tank corrosion, seal degradation, and hydraulic system failures—resulting in over 45 days of annual downtime. Consequently, the core procurement requirements focused on: corrosion resistance, seal longevity, and stability under high-load operation. The procurement budget was capped at approximately RMB 395,000 per unit, with the requirement that the vehicle be operable under a Class C driver’s license (blue plate), enabling agile maneuverability through narrow urban streets. Following open tendering, Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as “Chengli”) won the bid with its CLW5040TWC6 sewage treatment vehicle model. A total of two units were delivered, each priced at approximately RMB 168,000 (based on publicly disclosed tender information). Comparative Parameter Analysis of Five Mainstream Models To assist procurement units in gaining an intuitive understanding of mainstream market offerings, we compare five blue-plate sewage treatment vehicles—each built on the Dongfeng D6 chassis—that participated in this tender. Data sources include the Ministry of Industry and Information Technology (MIIT) announcements (e.g., CLW5040TWC6) and Chengli’s product database. | Model | Chassis Model | Tank Capacity (m³) | Max. Suction Depth (m) | Engine Power (kW) | Corrosion Protection Process | Seal Material | Reference Price (RMB 10,000s) | |--------|----------------|------------------------|---------------------------|----------------------|------------------------------|----------------|-------------------------------| | Chengli CLW5040TWC6 (Winning Bid) | Dongfeng D6 | 3.5 | 8 | 85 | Full-tank hot-dip galvanization + epoxy resin coating | Fluoroelastomer O-rings (temp. range: −20°C to +200°C) | ~16.8 | | Competitor A | Dongfeng D6 | 3.2 | 7 | 80 | Standard anti-corrosion paint | Nitrile rubber (temp. range: −10°C to +80°C) | ~15.5 | | Competitor B | Dongfeng D6 | 3.8 | 6 | 85 | Single-layer galvanization | Silicone rubber (temp. range: −40°C to +180°C) | ~17.2 | | Competitor C | Dongfeng D6 | 3.0 | 8 | 80 | Epoxy resin coating | Nitrile rubber | ~14.8 | | Competitor D | Dongfeng D6 | 3.6 | 7.5 | 85 | Standard anti-corrosion paint + localized hot-dip galvanization | Fluoroelastomer | ~16.5 | Note: Prices listed above are reference values derived from publicly disclosed tender information or local procurement conventions; actual transaction prices may vary depending on configuration, order volume, and timing. Multi-Dimensional Comparative Analysis: Why Did the Chengli CLW5040TWC6 Win the Bid? 1. Corrosion-Resistant Coating: The ‘Guardian’ for Hot-Humid Environments Chongqing’s high-humidity, high-salinity environment poses severe corrosive threats to tanks and p