JB/T 51131-1999

This standard is used by internal combustion engine manufacturers and quality inspection agencies to grade the quality of fuel tanks for small and medium power engines. It establishes three quality levels (qualified, first-class, and premium) to help users select appropriate products and ensures critical performance such as leak tightness, durability, and cleanliness.

该标准由内燃机制造商和质检机构使用，用于对中小功率内燃机油箱进行质量等级评定。它通过设定合格品、一等品和优等品三个等级，帮助用户选择合适质量水平的产品，并确保油箱的密封性、耐久性和清洁度等关键性能。

This standard JB/T 51131－1999 specifies the product quality grading for fuel tanks of small and medium power internal combustion engines, including quality indicators, test methods, and inspection rules. It classifies fuel tanks into three grades: qualified, first-class, and premium. Key technical requirements cover leak tightness, vibration endurance, cleanliness, mounting dimensions, and paint film quality. Test methods include leak tests, vibration endurance tests, and cleanliness checks. Inspection rules use sampling plans with nonconformity classification (A, B, C). The standard provides a unified quality grading basis for the internal combustion engine industry.

本标准JB/T 51131－1999规定了中小功率内燃机油箱的产品质量分等，包括质量指标、试验方法和检验规则。标准将油箱分为合格品、一等品和优等品三个等级，涉及密封性、振动耐久性、清洁度、安装尺寸、漆膜质量等多项技术要求。试验方法包括密封性试验、振动耐久试验和清洁度检测等。检验规则采用抽样方案，按不合格分类（A、B、C类）进行判定。该标准适用于油箱产品的检验和评定，为内燃机行业提供了统一的质量分级依据。