PD Meter – Fluid Data

• Minimum and Maximum Flow Rate—Specification of the minimum flow rate is a requirement for meeting the specified linearity. Maximum flow rate is based on continuous and intermittent ratings. Commonly used engineering units are gallons per minute (GPM) and barrels per hour (BPH).

• Viscosity—Specify normal and maximum viscosity. These parameters are used to determine clearances, type of external housing (single or double) and type of rotary shaft seal. The engineering units and conversion factor are as follows.

Cs = (Cp)/(SG)
SSU x 0.21589 = Cs (approximate)

Cs = Kinematic viscosity in centistokes
Cp = Absolute viscosity in centipoise
SSU = Saybolt Universal Unit
SG = Fluid Specific Gravity (water = 1 at 60°F)