Government procurement case of Dongfeng’s new sewage treatment vehicle in Yantai: Three-year failure rate analysis and in-depth interpretation of the winning bid solution. In the municipal sanitation sector, sewage treatment vehicles serve as critical equipment for responding to sudden sewage leaks, pipeline cleaning, and emergency handling; their reliability directly impacts the efficiency and cost of urban environmental maintenance. In 2023, the Urban Management Bureau of a district in Yantai procured three units of Dongfeng-chassis-based new sewage treatment vehicles via public tender, delivered by Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as 'Chengli SPV'). This article conducts an in-depth analysis based on the actual three-year operational data of these vehicles, combined with public tender information and maintenance records, covering dimensions such as failure rate, after-sales response, and spare parts supply, providing reference for similar procurement projects. I. Project Background and Procurement Overview To address emergency sewage treatment needs arising from urban pipeline renovation in aging districts, the Urban Management Bureau of a district in Yantai planned to procure three sewage treatment vehicles equipped with 'sewage suction + solid-liquid separation + wastewater purification' capabilities. Following local procurement practices, the project budget was capped at approximately RMB 2.057 million, with an estimated unit price of around RMB 600,000. After multiple rounds of competitive bidding, Chengli SPV won the contract, leveraging the high compatibility of the Dongfeng chassis, complete official vehicle announcements (e.g., CLW5070GSSD6 series models), and its lifetime after-sales service commitment. These vehicles are built on Dongfeng DOLICA chassis, compliant with China VI emission standards. The upper structure features a 2.5-ton vacuum pump, stainless-steel sewage tank, and automatic backflush system, with a designed treatment capacity of 30 cubic meters per hour. Since delivery in June 2023, they have accumulated over 12,000 operational hours across six subdistricts within the jurisdiction and participated in 47 emergency response missions. II. Fault-Type Distribution Based on Authentic Maintenance Records According to Chengli SPV’s three-year after-sales maintenance log (as of June 2026), a total of 32 maintenance records were generated across the three vehicles. Below is the fault-type distribution analysis: Fault Type | Occurrence Count | Percentage | Primary Root Cause Analysis Vacuum Pump Seal Failure | 8 | 25% | Accelerated wear of sealing rings due to frequent suction of sandy sewage Hydraulic Line Leakage | 6 | 18.75% | Sealing degradation at joints caused by prolonged high-pressure operation Electrical System Faults (Sensors/Controllers) | 5 | 15.63% | Poor electrical contact resulting from sewage splashing onto wiring Internal Tank Corrosion | 4 | 12.5% | Local peeling of anti-corrosion coating due to prolonged exposure to acidic sewage Engine/Chassis-Related Faults | 4 | 12.5% | Routine maintenance part replacements covered under Dongfeng’s nationwide warranty program Others (Valve Jamming, Filter Clogging) | 5 | 15.63% | Improper operation/maintenance or presence of large particulates in influent water Data indicates that vacuum pump seal failure and hydraulic line leakage are the most common issues, collectively accounting for over 43%—a direct reflection of the vehicles’ high-load, harsh operating conditions. Notably, engine and chassis-related faults represent only 12.5% of all incidents, and all were resolved swiftly through Dongfeng’s nationwide warranty network, underscoring the chassis’s reliability. III. Chengli’s After-Sales Response Speed: Timeliness Analysis from Repair Reporting to Operational Resumption Among the 32 maintenance records, Chengli SPV’s after-sales team—including authorized local service stations—demonstrated the following respo