Government procurement case of the new Dongfeng sewage treatment vehicle in Xining: Emergency replenishment purchase and low-temperature environmental adaptation solution. In November 2025, a municipal sanitation department in Xining experienced an unexpected blockage in an aging pipeline within its jurisdiction, causing domestic sewage overflow and creating an urgent need for sewage treatment vehicles with high-efficiency suction/discharge and solid-liquid separation capabilities. Given Xining’s location on the Qinghai-Tibet Plateau—where winter temperatures can drop below -20°C—conventional equipment faces risks such as difficult cold-starting and hydraulic system failure under low-temperature conditions. Consequently, the procuring entity explicitly emphasized three core technical requirements in the tender documents: 'anti-freeze starting performance', 'low-temperature hydraulic stability', and 'winter maintenance plan'. This article uses this emergency replenishment procurement as a case study to illustrate how Chengli Special Purpose Vehicle Co., Ltd. rapidly responded and completed delivery through integration of the new Dongfeng chassis and a customized upper-structure solution. Project Background: A municipal sanitation department in Xining urgently needed to procure three sewage treatment vehicles following an unexpected sewage overflow incident within its jurisdiction. Tender requirements included: China VI emission standard compliance, Dongfeng chassis, suction/discharge and solid-liquid separation functionality, operational capability at -25°C, and delivery within 15 days. I. Background of the Urgent Requirement: Low-Temperature Challenges at High Altitude Xining’s average elevation is approximately 2,300 meters. Winters are long and dry, with temperatures frequently falling below -15°C from November through March of the following year. At project initiation, the procuring entity clearly identified the following common issues encountered by conventional sewage treatment vehicles operating under high-altitude, low-temperature conditions: • Difficult engine starting: Diesel engine oil viscosity increases and battery capacity declines at low temperatures, potentially preventing normal engine startup. • Hydraulic system failure: Hydraulic fluid loses flowability at low temperatures, leading to poor pump suction, sluggish actuator response, or even component jamming. • Pipeline freezing and blockage: Sewage pipelines, suction/discharge pump bodies, and valves are prone to freezing at low temperatures, impairing operational efficiency and potentially damaging equipment. Therefore, the tender documents explicitly required vehicles to be equipped with fuel heaters, low-temperature starting aids (e.g., glow plugs, intake air heaters), low-temperature hydraulic oil (rated for operation down to at least -35°C), and a comprehensive winter maintenance plan. Additionally, considering the urgency of the emergency replenishment purchase, the delivery timeline was compressed to under 15 days. II. Expedited Tender Process: Focus on Dongfeng Chassis and Chengli Upper Structure According to publicly released tender information, the total procurement budget was capped at approximately RMB 1.36 million, covering three new Dongfeng-chassis sewage treatment vehicles. The tender notice was issued on November 15, 2025. Evaluation criteria weighted 'technical solution adaptability' at 40%, 'delivery capability' at 30%, 'price reasonableness' at 20%, and 'after-sales service' at 10%. Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as 'Chengli') submitted a bid featuring the Dongfeng EQ1185LJ9CDE chassis (model reference per GB/T 3730.1-2001 standard). This chassis is powered by a China VI-compliant Cummins B6.2NS6B230 engine delivering approximately 169 kW output, offering excellent high-altitude adaptability. For the upper structure, Chengli selected the CLW5180TWCE6-type sewage treatment vehicle (parameters certified