I. Case Background: Sewer Cleaning Requirements and Procurement Selection by a Municipal Sanitation Department in Wuhu In 2025, the Urban Management Bureau of a district in Wuhu City planned to procure a batch of blue-license-plate sewer cleaning trucks to address routine maintenance of urban drainage networks, rivers, and culverts. Based on local procurement practices and publicly available tender information, the budget was controlled at approximately RMB X0,000 per unit, with key requirements including C1 driver’s license operability, unrestricted blue-plate access in urban areas, and a 3-cubic-meter tank capacity. After multiple rounds of evaluation, X units of the Dongfeng double-cab sewer cleaning truck (blue plate, 3 m³) were ultimately delivered—manufactured by Chengli Special Purpose Vehicle Co., Ltd. This model is built upon a Dongfeng chassis, with official announcement model number CLW... series (specific model numbers detailed below). It is currently operating reliably in daily service at the client’s facility. Customer feedback indicates that sewer cleaning operations take place in harsh environments, where sludge has high water content and significant sand content, requiring frequent equipment startup and high-pressure flushing. The Dongfeng double-cab sewer cleaning truck (3 m³) delivered for this project features a heavy-duty chassis design, effectively resolving common issues in conventional models—such as tank corrosion and hydraulic system overheating. As the original equipment manufacturer, Chengli Special Purpose Vehicle provided direct factory support, eliminating intermediaries and saving the procuring entity approximately RMB 8,000–15,000 per unit. II. Equipment Fatigue Management under High-Frequency Operational Scenarios During Wuhu’s rainy season and routine drainage maintenance, sewer cleaning trucks often operate continuously for 8–10 hours per day—posing severe challenges for fatigue management: Are tank welds robust enough? Can the hydraulic pump sustain prolonged high-pressure operation? Is the sealing system corrosion-resistant? Practical field experience with the delivered Dongfeng double-cab sewer cleaning truck (3 m³) demonstrates that Chengli’s factory implemented multiple optimizations specifically for high-load conditions: • Tank Material: High-strength wear-resistant steel plates (4 mm thickness—conventional products typically use 3 mm), with all welds inspected via X-ray radiography to ensure crack resistance under long-term high-pressure flushing. • Hydraulic System: Equipped with imported multi-way valves and a dual-pump, dual-circuit design, enabling precise hydraulic oil temperature control; oil temperature remains below 80°C even after six consecutive hours of summer operation—preventing sluggish actuation due to overheating. • Sealing Components: Rear tank cover uses fluorosilicone rubber sealing strips, offering superior resistance to acids, alkalis, and oil contamination—extending service life by approximately two times compared to standard rubber. • Chassis Compatibility: Dongfeng double-cab chassis (model EQ... series) features a reinforced frame, with rear axle load capacity up to 6 tons—fully meeting transport demands for a fully loaded 3-m³ sludge volume (~5 tons). These design details received expert recognition during government procurement reviews and directly reduced subsequent operation and maintenance costs. Referencing official announcement parameters for models such as CLW5070GSSD6 in Chengli’s technical knowledge base, both chassis and upper-body assemblies have passed mandatory national inspections and comply with China VI emission standards. III. Key Highlights of Chengli’s Heavy-Duty Operational Design The Dongfeng double-cab sewer cleaning truck (blue plate, 3 m³) procured for the Wuhu project incorporates the following heavy-duty design features: 1. Chassis Adaptability The Dongfeng double-cab cab accommodates five occupants (including the driver), satisfyi