In the municipal sanitation sector, procurement of sewage treatment vehicles often involves complex contractual terms, delivery schedules, and warranty period calculations. A municipal sanitation department in Jiaxing recently procured a DFAC National VI 3308 mm wheelbase sewage treatment vehicle—a case study offering valuable reference for similar projects. Based on this case, this article provides an in-depth analysis covering essential procurement contract clauses, delivery schedule stipulations, warranty period calculation methods, Chengli Special Purpose Vehicle’s standardized contract practices, and frequently asked questions. I. Essential Procurement Contract Clauses: The Jiaxing Case Study According to publicly available tender information from a municipal sanitation department in Jiaxing, the procurement of the DFAC National VI 3308 mm wheelbase sewage treatment vehicle (referencing the official announcement parameters of Chengli CLW5070GSSD6 model) includes the following core clauses: Vehicle Specifications: DFAC chassis with 3308 mm wheelbase, compliant with National VI emission standards; upper-body configuration includes sewage tank, high-pressure cleaning system, vacuum pump, etc. Official announcement parameters clearly specify overall vehicle dimensions, gross vehicle weight, and tank capacity (e.g., 5 m³ or 8 m³, customizable per requirements). Pricing Terms: Budget range approximately RMB 335,000–446,000; unit price around RMB 350,000 (based on local procurement conventions), inclusive of VAT, transportation, and initial operator training fees. Payment Terms: 30% advance payment; 65% upon successful acceptance; remaining 5% warranty deposit paid upon expiration of warranty period. Acceptance Criteria: Must pass vehicle announcement consistency inspection and upper-body functional testing (e.g., sewage suction efficiency ≥80%, cleaning pressure ≥10 MPa). As the supplier, Chengli Special Purpose Vehicle typically specifies in its contracts the clause “Original-chassis nationwide warranty (by chassis manufacturer) and lifetime upper-body service.” This was reflected in the Jiaxing case—for instance, the contract stipulates that DFAC chassis warranty is provided by authorized DFAC service stations, while Chengli assumes after-sales support for the upper-body assembly, guaranteeing spare parts response within 24 hours. II. Delivery Schedule Stipulations: From Production to On-site Deployment In the Jiaxing case, delivery schedule constituted one of the key contractual clauses. Based on Chengli Special Purpose Vehicle’s production capacity (standard models delivered within 7–15 days), the contract specifies the following: Production Cycle: Approximately 10 working days for upper-body assembly and commissioning after chassis arrival at the factory. Logistics & Transportation: Flatbed truck transport from Suizhou, Hubei to Jiaxing—approximately 3–5 days. Total Delivery Time: No more than 25 calendar days from contract signing to vehicle arrival on site. Chengli’s local manufacturing base in Suizhou—combined with its zero-inventory dispatch model—ensures stable and reliable delivery performance. Customer feedback indicates actual delivery time averaged ~20 days, fully compliant with contractual commitments. A 5-day buffer period is contractually reserved for holidays or adverse weather conditions. III. Warranty Period Calculation Method: Separate Calculation for Chassis and Upper-Body The Jiaxing case adopts the industry-standard practice of calculating warranty periods separately for chassis and upper-body components: DFAC Chassis: 18 months from date of vehicle delivery or 100,000 km mileage—whichever occurs first—covered under DFAC’s nationwide warranty network. Chengli Upper-Body: 24 months, calculated from the date of successful acceptance. Chengli offers lifetime service: free repairs during warranty period; post-warranty service incurs material cost only. This dual-calculation method is explic