Xuchang Dongfeng New Sewage Treatment Vehicle Procurement Case: Equipment Selection and Heavy-Duty Solution under High-Load Operations. As urban sewage treatment demands continue to grow, sanitation units face mounting operational pressure. For instance, a municipal sanitation department in Xuchang is responsible for sewer cleaning, sludge suction, and emergency response across multiple industrial and residential zones. Its equipment operates over 200 hours per month, often running continuously for 24 hours. Under such high-frequency, high-intensity usage scenarios, equipment fatigue management has become a critical challenge: conventional sewage treatment vehicles frequently suffer from hydraulic system overheating, tank seal failure, and chassis overload—leading to frequent breakdowns and soaring maintenance costs. Recently, the department procured a batch of new sewage treatment vehicles built on Dongfeng chassis through government procurement procedures, ultimately selecting Chengli Special Purpose Vehicle’s solution. Based on publicly available tender information, this article provides a detailed analysis of this case and explains how Chengli addresses high-load challenges through heavy-duty operational design. I. Project Background and Procurement Requirements At the end of 2025, the municipal sanitation department issued a public tender notice for sewage treatment vehicles, with a budget capped at approximately RMB 310,000. The vehicles were required to perform sewage suction, solid-liquid separation, and emergency drainage. In line with local procurement practices, the buyer explicitly specified three core requirements: 1. High-Load Adaptability: Vehicles must support continuous daily operation of at least 10 hours and handle heavily contaminated sewage containing large amounts of silt and debris. 2. Chassis Reliability: The chassis must support a payload capacity of ≥8 tons and comply with China VI emission standards to ensure long-term regulatory compliance. 3. After-Sales Support: Suppliers must provide localized maintenance services and guarantee spare parts delivery within 24 hours. After multiple rounds of technical evaluation and commercial negotiations, Chengli Special Purpose Vehicle secured the contract with its integrated solution—Dongfeng chassis paired with a heavy-duty upper assembly—and delivered three sewage treatment vehicles. Customer feedback indicates stable performance in actual operations, particularly under high-load conditions, where equipment fatigue levels were significantly lower than those observed with competing models previously deployed. II. Equipment Fatigue Management under High-Load Operations In the sanitation equipment sector, high-load operations—such as continuous daily operation exceeding 10 hours—accelerate wear on critical components. Key fatigue-prone areas in sewage treatment vehicles include: • Hydraulic System: Frequent suction and discharge cycles cause hydraulic oil temperature to rise, accelerating seal degradation and reducing system efficiency. • Tank Structure: Prolonged exposure to vacuum pressure and corrosive sewage increases the risk of fatigue cracks at weld seams. • Chassis Suspension: Extended full-load travel (approximately 8–10 tons) subjects leaf springs and tires to extreme stress. To address these challenges, Chengli implemented the following key design enhancements in the delivered vehicles: • Enhanced Radiator: An independent hydraulic cooling module ensures oil temperature remains below 65°C, extending seal service life by 2–3 times. • Reinforced Tank: Constructed using Q345B high-strength steel, with tank wall thickness increased to 5 mm (standard: 4 mm); 100% non-destructive testing applied to all weld seams. • Optimized Chassis: Based on the Dongfeng DOLICA chassis (model CLW5080GXWD6), rear axle load capacity upgraded to 8 tons, complemented by reinforced leaf springs to ensure stability and durability under full-load conditions.