The number of lines in an establishment is the number of faucets in an establishment, not the number of couplers.
# of lines = # of faucets (taps)
Example: An establishment has two bars that are served from a single walk-in. Each bar has eight taps/faucets. That establishment has 16 lines, not 8.
If an establishment has two walk-ins, it should be considered two different establishments.
See also - Brands - Best Practices