JB/T 53390-1999

Manufacturers and quality inspection departments of mechanical seals use this standard to grade and inspect reaction bonded silicon nitride seal rings. It defines specific technical requirements for qualified, first-grade, and premium products, helping companies control quality, improve reliability, and ensure sealing performance and service life in mechanical seal systems.

机械密封件制造企业和质量检验部门使用本标准，对反应烧结氮化硅密封环进行质量等级评定和出厂检验。该标准通过明确合格品、一等品和优等品的具体技术指标，帮助企业控制产品质量、提升产品可靠性，并确保密封环在机械密封系统中的密封性能和使用寿命。

This standard specifies quality grades, test methods, and sampling methods for reaction bonded silicon nitride seal rings used in mechanical seals. Seal rings are classified into three grades: qualified, first-grade, and premium. The pass rate for critical items must be 100%, while major items require ≥85%, ≥90%, and ≥95% respectively. Detailed inspection criteria include flatness, surface roughness, bright spots, porosity, bulk density, apparent porosity, hardness, flexural strength, and thermal stability. Test methods follow JB/T 8724—1998. Sampling requires at least 100 pieces from user or manufacturer stock, with 24 pieces tested.

本标准规定了机械密封用反应烧结氮化硅密封环的质量等级、试验方法和抽样方法。密封环按质量分为合格品、一等品和优等品三个等级，关键项次合格率要求100%，主要项次合格率分别为≥85%、≥90%和≥95%。标准详细列出了密封面平面度、表面粗糙度、亮点、气孔、体积密度、显气率、硬度、抗折强度、热稳定性等多项检测指标及分等要求。试验方法引用JB/T 8724—1998，抽样要求从用户或制造厂仓库抽取，样本数不少于100只，受检数量24只。