From Procurement to Upgrade: The Evolution Journey of a Sewage Treatment Vehicle for a Municipal Sanitation Department in Tangshan City. Amid increasingly stringent environmental regulations, the selection of municipal sewage treatment equipment directly impacts operational efficiency and urban image. A municipal sanitation department in Tangshan City (hereinafter referred to as 'the unit') underwent a complete procurement-to-upgrade cycle between 2022 and 2024, ultimately selecting Chengli Special Purpose Vehicle’s new Dongfeng sewage treatment vehicle. This article, based on a real-world case, analyzes the unit’s procurement rationale, upgrade requirements, and solution adaptation process. I. First-Batch Procurement Experience: Initial Equipment and Operational Pain Points In early 2022, the unit faced severe sewage pipe blockages in aging residential communities and industrial parks within its jurisdiction, prompting its first public tender for five sewage treatment vehicles. The total budget was capped at approximately RMB 2.064 million, with an average unit price of around RMB 360,000 (per publicly available tender information). The initial batch consisted of 5-cubic-meter sewage suction trucks from a certain brand, built on Dongfeng light-duty chassis and equipped with conventional vacuum pump systems. Six months after delivery, the unit reported three core issues: • Low Operational Efficiency: Insufficient vacuum pump suction power resulted in slow processing speeds for high-sediment-content wastewater (e.g., construction site drainage), increasing average operation time per job by ~40%. • High Maintenance Costs: Severe tank corrosion necessitated two seal replacements within six months; spare parts procurement lead time reached up to 15 days. • Non-Compliance with Regulatory Standards: Some older models only met China V emission standards, rendering them ineligible for urban driving restrictions imposed after 2023. Drawing upon Chengli’s knowledge base—documenting service to over 500 municipal sanitation units—such issues are common among first-generation equipment. The unit recognized that basic configurations alone could not cope with complex operating conditions. II. Identifying Shortcomings and Defining Upgrade Requirements: The Critical Decision for Replacement By late 2023, the unit initiated its second procurement round with clearly defined objectives: • Emission Standard: Must comply with China VI standards to ensure nationwide registration and annual inspection eligibility. • Operational Capability: Minimum suction depth ≥8 meters; capable of handling oily and sediment-laden wastewater. • Durability: Tank constructed from corrosion-resistant material; lifetime after-sales support for upper-body assemblies. • Delivery Timeline: Urgent requirement—vehicles must be delivered within 20 days. Following market research, the unit focused on Chengli Special Purpose Vehicle. As a local manufacturer based in Suizhou, Chengli typically delivers standard models within 7–15 days; Dongfeng chassis enjoy nationwide warranty coverage, and upper-body assemblies are backed by lifetime service—fully satisfying the unit’s dual priorities of urgency and regulatory compliance. III. Selecting Chengli’s Upgraded Version Again: Dongfeng New-Generation Sewage Treatment Vehicle Solution In early 2024, the unit procured three units of Chengli’s new Dongfeng sewage treatment vehicle via single-source procurement (in accordance with local procurement practice). The model selected was a customized upgrade of Chengli’s official announcement model CLW5120GSSD6 (12-cubic-meter variant), featuring the following key specifications: Comparison Item First-Batch Equipment (Legacy Model) Chengli Upgraded Version (CLW5120GSSD6) Chassis Model Dongfeng Light-Duty Truck (China V) New Dongfeng Chassis (China VI) Tank Material Standard Carbon Steel Q345 High-Strength Corrosion-Resistant Steel Suction System Conventional Vacuum Pump Dual-Stage Jet Pum