I. Project Background: Emergency Support Before Spring Festival — Urgent Procurement of Sewage Treatment Vehicles by a District in Zibo City In January 2025, the Urban Management Bureau of a district in Zibo City, Shandong Province, faced heightened sewage treatment pressure due to the overlap of the Spring Festival holiday and winter precipitation. To ensure timely transfer and treatment of domestic sewage and industrial wastewater during the holiday period, the bureau initiated an emergency procurement process, planning to acquire two new Dongfeng-brand sewage treatment vehicles. Requirements included a China VI-compliant chassis, an upper assembly equipped with high-efficiency solid-liquid separation and disinfection systems, and delivery and commissioning within seven days. According to publicly released tender information, the project budget was capped at approximately RMB 966,000, with a unit price of around RMB 420,000. Following multiple rounds of evaluation, Chengli Special Purpose Vehicle Co., Ltd. secured the contract, leveraging its strong integration capability with Dongfeng chassis, rapid after-sales response, and localized service advantages. Two Dongfeng DOLICA-chassis sewage treatment vehicles were successfully delivered, with reference model CLW5070GSSD6 (a comparable chassis model listed in official announcements). II. Chengli’s Winning Solution: Dongfeng Chassis + Customized Upper Assembly Meeting Emergency Support Requirements 1. Vehicle Configuration and Technical Specifications Chengli’s solution centered on the Dongfeng DOLICA chassis (China VI diesel engine, rated power approx. 95 kW), paired with Chengli’s self-developed sewage treatment upper assembly system. This vehicle integrates sewage suction, solid-liquid separation, UV disinfection, and reclaimed water reuse functions. The tank offers an effective capacity of approximately 5 m³, with an hourly treatment capacity of 8–12 tons (depending on influent concentration). Key specifications refer to the design of the CLW5070GSSD6 model in Chengli’s product database: Chassis Model: Dongfeng EQ1075SJ3CDF Engine: Yuchai YCY24140-60 (140 HP) Emission Standard: China VI Sewage Tank Material: Q235 carbon steel (with internal anti-corrosion coating) Separation System: Stainless-steel rotary screen + sludge screw conveyor Disinfection Method: UV lamps (120 W) Cleaning Pump: Flow rate 60 L/min, pressure 0.6 MPa Customer Feedback: During its first Spring Festival support mission post-delivery, the vehicle operated continuously at full load for seven days, treating approximately 300 tons of sewage without any breakdowns or unplanned shutdowns. III. Key Support Measures: How Were Unexpected Failures Addressed During the Spring Festival Holiday? The Spring Festival holiday represents a high-risk period for municipal infrastructure support. To address this, Chengli formulated a dedicated emergency response plan for this project: • Direct Spare Parts Dispatch: Critical consumables (e.g., seals, filters, UV lamps) were pre-stocked locally in Zibo, with a commitment to deliver replacements directly to the site within 24 hours. • Remote Guidance + Local Response: Chengli’s after-sales engineers provided real-time video-based remote diagnostics, while simultaneously coordinating on-site technical support from Dongfeng’s authorized service stations across Shandong Province. In practice, one vehicle experienced pump seal leakage on Chinese New Year’s Eve; the after-sales team completed replacement within four hours. • Operator Training: Prior to delivery, three days of hands-on training were conducted for Urban Management Bureau operators, covering routine maintenance, emergency troubleshooting, and winter freeze-prevention measures. According to Chengli’s after-sales service records, these vehicles achieved an operational availability rate exceeding 98% between January and March 2025, with only one minor fault occurring—and resolved promptly. Customer evaluation: “Cheng