螺纹接套 meaning in Chinese

connecting nipple
threaded bush
threaded nipple

Nipple connections for pressure gauges and their accessories
压力表及其附件用螺纹接套连接
All wetted valve components - test cocks , ball valve shutoffs , pipe nipples , body and cover , and check modules are made from " lead free " stainless steel or plastic construction
全焊接阀门部件-测试旋塞，球阀关闭阀，管螺纹接套，阀体和阀盖，以及止回阀模块都采用“无铅”不锈钢或塑料结构。