What’s the difference between Firm service and Interruptible
service?
Firm service is the highest quality sales or transmission
service offered to customers under a filed rate schedule that
anticipates no planned interruption. It is usually associated
with distribution companies that serve residential customers and
other "high priority end-users," but can also apply to upstream
pipelines and other Interruptible service is subject to
interruption at the option of the pipeline. Tariffs for
interruptible service are cheaper than firm service.