I. Background: Pain Points in Municipal Drainage System Cleaning and Initial Procurement A municipal sanitation department in Qujing City (hereinafter referred to as 'the unit') is responsible for routine maintenance of dozens of kilometers of drainage pipelines within its jurisdiction. With the onset of the rainy season, sediment accumulation in pipelines has become increasingly severe. Traditional manual cleaning methods suffer from low efficiency and high safety risks, creating an urgent need for specialized vehicles. In early 2023, the unit procured two Dongfeng dual-cab sewage suction trucks via public tender as its first batch—specifying blue license plates and 3-cubic-meter tanks, with a budget cap of approximately RMB 134,000 per unit. According to publicly available tender information, three suppliers participated in the bidding process, and ultimately two units were delivered at a unit price of approximately RMB 118,000. The first-batch vehicles featured the classic Dongfeng dual-cab chassis, accommodating up to five operators. Their compact dimensions (approx. 5.5 m × 1.9 m × 2.2 m) comply with Blue License Plate (Class C) driving requirements. The tank capacity is approximately 3 cubic meters, equipped with a high-pressure cleaning system and vacuum suction unit, offering a theoretical operational radius within 3 km. Initial performance was acceptable; however, after two months of actual operation, the unit identified several shortcomings. II. Identified Issues: Actual Performance and Shortcomings of the First-Batch Vehicles During operation of the first-batch vehicles, frontline operators reported the following issues: • Insufficient suction efficiency: For hard deposits (e.g., hardened silt, gravel-silt mixtures), the original suction pump lacked sufficient power, extending single-operation time by ~30% and requiring repeated flushing to complete cleaning. • Inadequate tank corrosion protection: Only standard anti-rust paint was applied internally; localized corrosion appeared after three months of frequent exposure to corrosive wastewater, compromising tank longevity and cleaning effectiveness. • Unstable high-pressure pump pressure: After continuous operation exceeding two hours, the high-pressure pump’s output pressure dropped significantly, failing to meet deep-pipe flushing requirements. • Slow after-sales service response: Repair turnaround time exceeded 72 hours following vehicle failures, disrupting scheduled cleaning operations. These issues directly contributed to an 85% completion rate for the unit’s 2024 cleaning tasks, while monthly average maintenance costs per vehicle increased by approximately RMB 2,000. Consequently, when planning its second procurement batch, the unit decided to raise technical specifications and seek a more reliable, upgraded solution. III. Evolved Requirements: Upgraded Specifications for the Second Procurement Batch Based on lessons learned from the first batch, the unit launched its second sewage suction truck procurement initiative at the end of 2024, with markedly enhanced requirements: • Suction Pump Upgrade: Must feature a high-flow, high-head vacuum suction pump capable of suction depths ≥ 8 meters, improving suction efficiency for hard deposits by ≥ 50%. • Tank Corrosion Protection Upgrade: Internal tank surfaces must be coated with corrosion-resistant materials (e.g., epoxy resin or fiberglass lining), ensuring ≥ 5 years of corrosion resistance. • High-Pressure Pump Requirement: Must incorporate a premium imported-brand high-pressure pump with a rated pressure ≥ 20 MPa, maintaining stable pressure for ≥ 4 hours of continuous operation. • After-Sales Service Guarantee: Supplier must provide nationwide chassis warranty coverage and lifetime upfit service, with spare parts shipped directly within 24 hours. • Budget Control: Unit price capped at approximately RMB 157,000 (based on current market reference)