Pain Points of Aging Equipment: Sanitation Challenges in Wenzhou’s Coastal Humid and Hot Environment. As a coastal city in Zhejiang Province, Wenzhou experiences year-round high temperatures and humidity, along with frequent rainy seasons—posing extremely high demands on the corrosion resistance and sealing performance of municipal sanitation vehicles. During its annual equipment inspection at the end of 2025, a municipal sanitation department discovered the following issues with some aging sewage treatment vehicles (procured in 2018): Severe Chassis Corrosion: Due to the coastal salt fog environment, the chassis and tank of the original vehicles developed extensive rust spots within three years; some fasteners corroded and detached, leading to increased maintenance frequency. Seal Failure: Under high-frequency rainy-season operation (8–10 hours per day), the original rubber seals aged and swelled due to heat and humidity, causing sewage leakage and triggering complaints from nearby residents. Reduced Operational Efficiency: The aging pump system exhibited insufficient pressure after continuous operation, reducing single-cycle processing capacity from the designed 5 m³ to approximately 3 m³. These pain points directly disrupted normal sanitation operations—especially during the 2025 summer typhoon season, when the department had to temporarily deploy vehicles from other regions, increasing operational costs. Consequently, in early 2026, the department launched a new procurement initiative for sewage treatment equipment. New Requirements Survey: From Tender Specifications to On-site Verification. Prior to procurement, the department established a dedicated task force that visited multiple sanitation vehicle manufacturers and reviewed procurement cases from neighboring cities (e.g., Ningbo and Taizhou). According to publicly released tender information, core requirements for this procurement included: Chassis Requirements: Blue license plate (gross vehicle weight under 4.5 tons), Dongfeng D6 chassis, compliant with China VI emission standards. Tank Material: Stainless steel with corrosion resistance or carbon steel treated with specialized anti-rust coating, suitable for coastal climates. Sealing Performance: All sealing components must pass durability testing under hot-humid conditions (per GB/T 12480-2020 standard). Operational Efficiency: Minimum single-cycle processing capacity of 4 m³; continuous operation time ≥6 hours. Budget Control: Budget capped at approximately RMB 344,000 (aligned with local procurement conventions). During the survey, the task force paid particular attention to Chengli Special Purpose Vehicle Co., Ltd.’s CLW5070GSSD6 model (technical parameters sourced from the Ministry of Industry and Information Technology). This model features a Dongfeng D6 chassis, a 5 m³ tank volume, a high-flow pump, and has been validated in multiple locations nationwide (e.g., industrial park case in Guangdong Province). Additionally, Chengli’s service policy—'Original-chassis nationwide warranty + lifetime upfit service'—further strengthened the buyer’s confidence. Chengli’s Solution Alignment: Targeted Pain-Point Resolution. During the quotation phase, Chengli Sales Manager Zhang Yue (Tel: ) proposed a customized solution tailored to Wenzhou’s environmental conditions, with key improvements including: Upgraded Anti-Corrosion Coating: Tank coated with dual-layer 'epoxy zinc-rich primer + polyurethane topcoat', minimum thickness ≥200 μm, certified for salt-spray resistance (≥1000 hours). Enhanced Seal Durability: Fluoroelastomer (FKM) seals—resistant to high temperature and salt fog (operating temperature range: −20°C to +200°C)—installed with added dust caps to minimize direct rainwater exposure. High-Load Operation Adaptation: Pump system upgraded to dual