GB/T 1149.4-2008 in English

《GB/T 1149.4-2008内燃机 活塞环 第4部分：质量要求》由TC177（全国内燃机标准化技术委员会）归口，主管部门为中国机械工业联合会。
ＧＢ／Ｔ１１４９《内燃机　活塞环》为系列标准，分为十六个部分,本部分为ＧＢ／Ｔ１１４９的第４部分。 本部分自实施之日起代替ＧＢ／Ｔ１１４９．４―１９９４《内燃机活塞环　技术要求》。 ＧＢ／Ｔ１１４９的本部分规定了那些能够限定但通常不表达在图纸技术要求上的质量方面的要求。
本部分适用于下列活塞环：
―――整体的铸铁环或钢质压缩环；
―――组合活塞环（油环），由铸铁零件和弹簧零件组成的；
―――整体钢质油环和钢带组合油环，即钢带式的油环和刮片与衬环组成的油环。
本部分规定了检验方法（包含于ＧＢ／Ｔ１１４９．５）中规定的一些质量特性的极限值，还规定了那些尚无公认的定量检测方法的质量特性，这些特性不需放大，只用正常视力（或戴校正眼镜）检查，这些特征（表面缺陷）是环高、径向厚度及闭口间隙公差标准的补充。
本部分没有规定合格质量水平值（ＡＱＬ），需要时由供需双方按ＧＢ／Ｔ２８２８．１的规定共同商定。
本部分规定了往复活塞式内燃机及其在类似条件下工作的压缩机活塞环的质量要求，适用于直径小于或等于２００ｍｍ 的活塞环。本部分是对ＧＢ／Ｔ１１４９．４―１９９４《内燃机活塞环　技术要求》的修订，本部分与ＧＢ／Ｔ１１４９．４―１９９４的主要区别是：
―――ＧＢ／Ｔ１１４９．４―１９９４为等效采用ＩＳＯ６６２１-３：１９８３和ＩＳＯ６６２１-５：１９８８，而本部分为等同采用ＩＳＯ６６２１-５：２００５。

Scope

This part of GB/T 1149 specifies quality requirements that can be defined but usually not expressed in technical requirements for drawings. This standard applies to the following piston rings: - integral cast iron rings or steel compression rings; - combined piston rings (oil rings), consisting of cast iron parts and spring parts; - integral steel oil rings and steel belt combined oil rings, That is, the steel belt type oil ring and the oil ring composed of scraper and backing ring. This part specifies the limit values of some quality characteristics stipulated in the test method (included in GB/T 1149.5), and also specifies the quality characteristics for which there is no recognized quantitative detection method. Or wearing corrective glasses), these features (surface defects) are supplementary to the ring height, radial thickness and closed gap tolerance standards. This part does not specify the Acceptable Quality Level (AQL), and when necessary, it shall be agreed upon by both parties according to GB/T 2828.1. This part specifies the quality requirements for piston rings of reciprocating piston internal combustion engines and compressors operating under similar conditions, and is applicable to piston rings with a diameter less than or equal to 200 mm.