Replacing a Gate Station Heater
When natural gas is delivered from high pressure transmission pipelines to gas distribution pipelines the ownership of the gas changes, odorant is added, and the pressure of the gas is reduced. Town/Border stations are built to regulate, measure, and reheat the gas to replace the energy lost during pressure reduction. This last task is performed by the gas heater.
Gas heaters use circulating hot water to keep the gas above the dewpoint when it enters the lower pressure distribution system.
The project described in this case study is the replacement of a gas heater. In this case the scope of work included demolition and removal of the old heater, piping, and electrical wiring.
Clearing this old infrastructure requires extensive hydro-excavation. This type of excavation reveals buried pipes and conduits without mechanical damage. Once revealed the equipment and its connecting infrastructure can be removed.
After removal all piping and equipment are removed the material was transported to laydown yards and recycling centers.
The new foundation was located and laid out. Measurements were taken for the new piping which was then fabricated off site in our fabrication shop. More hydro-excavation was performed to make room for new piping and electrical conduits.
The base for the foundation was laid down and compacted. The foundation was formed and, reinforcing rod placed and tied. Concrete was poured and cured. While this was happening the piping was fabricated, blasted, hydrostatically tested, sand blasted, primed, and painted.
The lifts required cranes and rigging with the capacity to handle the old heater which weighed 18,000 lbs. and the new heater which weighed 30,000 lbs. These lifts required planning and were executed without incident.
After the new heater was set, prefabricated piping was connected, torqued and coated. Electricians routed control and power wiring through conduit and into boxes and panels for termination. The final phase was testing the heater and commissioning.
