I. Project Background: Procurement Case Study of Sludge Removal Equipment by a Municipal Sanitation Department in Wuxi In Q3 2025, a municipal sanitation department in Wuxi issued a public tender for one Dongfeng single-cab sludge suction truck to address sludge removal needs in aging urban drainage networks. Requirements included blue license plate compliance, 5 m³ tank capacity, and adherence to China VI emission standards. The department routinely maintains stormwater inlets and sewage pipelines across approximately 30 km², with an annual sludge removal volume exceeding 5,000 m³. The equipment must operate flexibly in narrow streets and residential areas while ensuring high reliability under intensive usage. Per the public tender notice, the project budget was capped at approximately RMB 281,000, requiring suppliers to deliver a fully integrated vehicle (chassis + superstructure) and commit to rapid after-sales response. Following multiple evaluation rounds, Chengli Special Purpose Vehicle Co., Ltd. delivered the CLW5070GSSD6 model sludge suction truck. The unit is now operational, with customer feedback indicating a ~30% improvement in operational efficiency and a significant reduction in failure rate. II. Equipment Selection and Solution Analysis 2.1 Core Requirements: Blue-Plate, 5 m³ Capacity + High-Load Operation Blue-plate sludge suction trucks are widely deployed in cities like Wuxi due to their eligibility for C-class driver’s licenses and exemption from traffic restriction policies—ideal for community-based operations. A 5 m³ tank capacity supports a single-load sludge volume of ~3–4 tons, meeting routine pipeline cleaning demands. However, frequent operation imposes stringent requirements on chassis durability, hydraulic system robustness, and tank longevity. Chengli’s solution leverages a Dongfeng single-cab chassis, certified under model CLW5070GSSD6, equipped with a China VI-compliant diesel engine delivering a rated power output of ~95 kW. The curb weight is controlled within 4.5 tons to ensure regulatory compliance for blue-plate registration. Per MIIT certification parameters, the tank is fabricated from Q235B carbon steel with a wall thickness of 4 mm, offering strong corrosion resistance and a design service life exceeding eight years. The hydraulic system employs a dual-gear pump configuration, achieving a maximum working pressure of 16 MPa, enabling simultaneous operation of suction, discharge, and self-dumping functions—and reducing cycle time per operation to ~15 minutes. 2.2 Heavy-Duty Operational Design: Addressing Intensive Usage To meet the sanitation department’s daily high-load operational demands, Chengli enhanced the sludge suction truck with the following features: Chassis Reinforcement: The Dongfeng single-cab chassis features a standard front axle rating of 2.5 tons and rear axle rating of 5 tons, paired with 7.00R16LT tires, elevating total payload capacity to ~6 tons—sufficient for full 5 m³ load transportation. Hydraulic System Redundancy: A dual-circuit hydraulic system is adopted—primary circuit controls the suction pump (maximum vacuum level: 85%), while the secondary circuit manages tank lifting and discharge valve actuation—eliminating single-point failure risks. Tank Corrosion Protection: Interior surfaces are coated with epoxy resin; exterior surfaces undergo sandblasting followed by anti-rust paint application—extending service life in corrosive sewage environments by ~40%. Intelligent Monitoring: Optional liquid-level indicator and vacuum pressure gauge provide real-time monitoring of tank status, preventing overloading or insufficient vacuum that could impair efficiency. These enhancements ensure >90% equipment availability even under demanding conditions—8 hours of daily operation over 30 consecutive days. Post-delivery feedback from the Wuxi project confirms no hydraulic leakage or tank corrosion issues occurred during high-frequency monsoon-season usage. III. Winning Bid P