Gas · Distribution
City Gate Station
The station where natural gas leaves the high pressure transmission pipeline and enters the local distribution network.
What it does
It cuts the pressure in two or three regulator stages, meters the gas for billing between the two companies and injects mercaptan so leaks can be smelled. Line heaters upstream of the regulators keep the gas from freezing as it cools on expansion. In Canada transmission pressure is reduced below 690 kPa (100 psi) here.
Basics
| Inlet | Transmission, about 200 to 1,500 psi |
| Outlet (Canada) | Below 690 kPa (100 psi) |
| Metering | Ultrasonic or turbine |
| Odorant | Mercaptan |
| Heating | Indirect fired line heater |
Common failures
- Regulator freeze up from hydrates when the heater is down
Troubleshooting
- Symptom
- Outlet pressure unstable in cold weather
- Likely cause
- Ice or hydrates at the regulator
- What to check
- Check line heater outlet temperature and the regulator pilot