The live-joint sealing method is a system that detects joints from inside live (gas flowing) pipes and injects a sealant at detected joints to prevent leaks from low-pressure cast-iron pipe joints.

• (1) Applicable to: low-pressure cast-iron pipes 75 mm to 300 mm in dia.
  　　(with spigot/gas pipe joints)
• (2) Length: 30 to 50 m/side/pit
• (3) Bends: passage up to four 45o bends on one side

A hole of half the pipe diameter in diameter is bored in a low-pressure main. A packer is placed into the pipe under no blow conditions (no gas escaping) to detect joints. City gas of an increased pressure is used to inflate the packer, thereby injecting a sealant into the yarn in the joint clearance. Providing sealing this way, the live-joint sealing method prevents leaks from joints.

• (1) Repair work under no-blow live pipe conditions
• (2) Places a packer in the pipe through a small hole
• (3) Stops the packer at a joint with the combined use of a joint sensor with the system
• (4) Use of city gas to inflate the packer ensures safety even if the packer breaks
• (5) Measures the gas pressure at both ends of the packer to counter the problem of a decrease in gas pressure