Process for Accessing Underground Pressurized Gas Main

摘要

A process is provided for accessing an underground pressurized gas main for retirement of replacement of the connection of a gas service pipe thereto. A gas main fixture that has a service tee adaptor and a pressurized chamber connected thereto is mounted onto the gas main with the tee adaptor above a tee plug on the gas service pipe. The chamber is closed against gas discharge and the tee plug is unscrewed from the gas service pipe while the pressure chamber is closed. The tee plug is removed through the service tee adapter and pressure chamber while minimizing gas discharged to atmosphere. The plug hole is preferably reamed through the pressure chamber while the chamber is closed to atmosphere, tapped for a straight fine thread, and a main plug with the fine thread is screwed into the tapped hole while limiting its depth of engagement.