Hallen Construction installs metering and regulating stations for our customers. These stations typically lie hidden under the sidewalks and roadways of the city and have several functions.
Metering and regulating station functions include regulation of the pressure in the distribution mains as the demands increase and reducing the pressure delivered to the system by large transmission pipelines.
There are a few of these stations that also monitor the amount of gas that is flowing. These stations are contained in underground vaults which house the piping and mechanical hardware required to monitor gas pressure and flow. They also feature valves that control the flow of gas, and on occasion, the valves can be remotely operated.
Hallen’s role in the installation of these stations begins with saw cutting the roadway and sidewalks. The excavations for the underground vaults are then performed, and wood shoring is installed. This is followed by the delivery of precast concrete vaults which are offloaded into the excavations with a crane. Once the vaults are installed, then the vault piping and the inter vault piping are also installed. In addition to the inter vault piping, control piping is installed between vaults and to the communication system. All piping for these stations is welded steel, which must pass x-ray and air or hydro testing.
The next part of the installation requires connecting the station to the transmission main and the distribution main. This is when the trench is excavated and the piping is installed. Once all the piping is installed, the mains and station are tested. Once the test is completed, the station is tied into the transmission main and the distribution main. The final step is backfilling of all excavations and roadway/sidewalk restoration.