- Cv
- Valve flow coefficient
- FL
- Liquid pressure recovery factor of a valve without attached fittings
- FP
- Piping geometry factor
- GF
- Liquid specific gravity at upstream conditions [ratio of density of liquid at flowing conditions to density of water at 60°F]
- Nx
- Numerical constants for units of measurement used
- p1
- Upstream absolute static pressure, measured two nominal pipe diameters upstream of valve-fitting assembly
- p2
- Downstream absolute static pressure, measured six nominal pipe diameters upstream of valve-fitting assembly
- pv
- Absolute vapor pressure of liquid at inlet temperature
- q
- Volumetric flow rate
- qmax
- Maximum flow rate at a given upstream condition
