concealed piping造句

• Probe into concealed piping technology of town gas pipeline for residential buildings
  城市住宅燃气管道暗敷技术的探讨
• Carry out regular leakage tests on concealed piping and check for overflowing tanks , waste , worn tap washers and other defects in the water supply system
  定期检查隐蔽水管，以防漏损，检查内部供水系统，修理有毛病的水箱、水头及其他的供水设施。