Government procurement case of the 3308 yellow-plate sewage treatment vehicle in Shijiazhuang: A comprehensive walkthrough—from joint procurement to Chengli’s successful bid and delivery. In northern cities—especially Shijiazhuang, where winter temperatures frequently drop below freezing—the anti-freeze starting performance and low-temperature hydraulic stability of sewage treatment vehicles are the top considerations for procuring entities. Based on a real government procurement case, this article details how a municipal sanitation department adopted a joint procurement model to standardize technical specifications, conduct centralized bidding, and ultimately achieve bulk delivery of Chengli’s 3308 yellow-plate sewage treatment vehicles, with special emphasis on winter operation solutions. This procurement project involved municipal sanitation departments across three districts/counties under Shijiazhuang’s jurisdiction, aiming to enhance regional sewage treatment capacity and address the growing urban sewage discharge demand. According to publicly released tender information, the project budget was capped at approximately RMB 3.589 million, with plans to procure 10 yellow-plate sewage treatment vehicles—each with an estimated budget of around RMB 337,000. Ultimately, Chengli Special Purpose Vehicle Co., Ltd. won the bid with a total contract value of approximately RMB 2.98 million, delivering 10 units of the CLW5180 yellow-plate sewage treatment vehicle (unit price approx. RMB 298,000, per publicly available tender data). Background of Joint Procurement: Cross-District Coordination for Cost Reduction and Efficiency Improvement This procurement was not conducted independently by a single entity, but rather led by a municipal-level sanitation authority in Shijiazhuang and jointly executed by municipal sanitation departments from three districts/counties, adopting a ‘joint procurement’ model. Key advantages of this approach include: • Economies of Scale Reduce Costs: Consolidating demand across multiple districts/counties enabled a one-time purchase of 10 units, lowering the unit procurement cost. Local procurement practice indicates that joint procurement typically reduces costs by 8%–12% compared to individual procurement. • Unified Technical Standards: Prevents post-purchase maintenance complications arising from inconsistent technical parameters across regions, facilitating unified fleet deployment and staff training. • Shorter Tender Cycle: Centralized bidding eliminates redundant procedures, shortening the overall timeline—from requirement announcement to bid award and delivery—by approximately 20 days. In practice, representatives from each district/county jointly established a Procurement Working Group responsible for defining technical requirements, reviewing tender submissions, and ultimately selecting Chengli Special Purpose Vehicle Co., Ltd. as the supplier. Development of Unified Technical Standards: Prioritizing Anti-Freeze Performance and Hydraulic Stability Given Shijiazhuang’s cold winters (with minimum temperatures reaching –15°C), the Procurement Working Group emphasized three critical technical requirements: • Anti-Freeze Starting Performance: Vehicles must start reliably at –20°C without external heating assistance. Chengli’s CLW5180 sewage treatment vehicle is built on a China VI-compliant chassis (per MIIT announcements, using a Dongfeng chassis) and equipped with a low-temperature starting system—including glow plugs and a low-temperature battery—to ensure ≥95% cold-start success rate during winter. • Low-Temperature Hydraulic Stability: The hydraulic system powers core functions such as suction, pumping, and mixing. Technical standards mandate use of low-temperature hydraulic oil (e.g., L-HV32) and installation of a heater in the hydraulic reservoir to guarantee normal system operation at –15°C. Chengli’s model employs low-temperature-resistant hydraulic seals; testing confirms zero leakage even at –