Case Background: Procurement of Sewage Treatment Vehicles by a Municipal Sanitation Department in Zunyi In early 2025, a municipal sanitation department in Zunyi procured a batch of new Dongfeng sewage treatment vehicles through public tender to meet growing demands for urban sewage treatment and pipeline desilting. The client specified requirements including high-efficiency suction, solid-liquid separation, and sewage recirculation treatment capabilities, along with adaptability to Southwest China’s hot-humid climate—imposing stringent demands on anti-corrosion coating performance and sealing component durability. Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as “Chengli”) was awarded the contract based on its mature product solutions and transparent pricing, delivering six units. These vehicles are now operating stably across Zunyi’s urban area and surrounding regions. Customer feedback indicates markedly improved operational efficiency, particularly under high-load conditions during the rainy season. Standard vs. Premium Configuration Comparison: Analysis of Chengli Dongfeng Sewage Treatment Vehicle Solutions For this procurement, Chengli offered two mainstream configuration options: Standard Version (reference model CLW5070GSSD6 chassis) and Premium Version (reference model CLW5180GSSD6 chassis). Both utilize Dongfeng chassis compliant with China VI emission standards; however, they differ in engine power, tank capacity, and functional configurations. Standard Version Configuration (Suitable for Routine, Light-Duty Applications) Chassis Model: Dongfeng DOLICA (reference CLW5070GSSD6 official announcement) Engine: Yuchai 140 HP, China VI emission compliant Tank Capacity: Approx. 5–6 m³ (combined sewage and clean water tanks) Core Functions: Suction pump (vacuum level ≥95%), solid-liquid separator, high-pressure cleaning system (equipped with imported plunger pump) Anti-Corrosion Treatment: Standard internal tank anti-corrosion coating Sealing Components: Conventional rubber O-rings (temperature resistance: −20°C to 80°C) Reference Unit Price: RMB 280,000–320,000 (per publicly available tender information) Premium Version Configuration (Designed for High-Load Operations and Hot-Humid Environments) Chassis Model: Dongfeng Tianjin (reference CLW5180GSSD6 official announcement) Engine: Cummins 210 HP, China VI emission compliant Tank Capacity: Approx. 8–10 m³ (combined sewage and clean water tanks) Core Functions: High-power suction pump (vacuum level ≥98%), high-efficiency solid-liquid separation system (treatment capacity ≥20 m³/h), automatic backflush system Anti-Corrosion Treatment: Internal tank coated with hot-dip galvanized + epoxy resin composite layer (enhanced salt-spray corrosion resistance) Sealing Components: Fluoroelastomer (FKM) O-rings (temperature resistance: −40°C to 200°C; resistant to oil and acids/alkalis) Reference Unit Price: RMB 380,000–450,000 (per publicly available tender information) Based on local procurement practices, the client selected the Premium Version, citing Zunyi’s frequent rainy season and high humidity levels. Standard sealing components tend to age rapidly under such conditions, whereas fluoroelastomer O-rings significantly extend service life and reduce maintenance costs. Value Analysis of Optional Equipment: Importance of Anti-Corrosion Coating and Sealing Components In Southwest China’s hot-humid environment, corrosion and sealing failure pose critical challenges for sewage treatment vehicles. Chengli’s optional equipment includes: Enhanced Anti-Corrosion Coating (Hot-Dip Galvanized + Epoxy Resin): Compared to standard coatings, salt-spray test duration increases by approximately 50%, effectively mitigating degradation caused by high humidity during the rainy season and extending tank service life by 3–5 years. Per publicly available tender data, this option adds RMB 15,000–20,000 per unit.