配管 tubing空调制冷配管 ACR tubing管道 piping,tubing制冷管路 refrigeration pipe line系统酸状况 acid condition system退火 annealing加压元件 pressure imposing element检修门 access door气封 vapor lock主管 main歧管 mainfold集管 header盐水管 brine line盐水集管 brine header旁通管 by-pass套管 tube-within-a-tube伸缩弯 expansion loop存油弯 oil loop液环 liquid loop