LDi – P43

Add friction from system flow resistance to "A.H." figure

Also known as "Viscous drag", "Scrubbing action", "Rotary flow", and "Reynolds effect".

Input Data:

Q gpm – GPM (steady state) Volumetric flow rate

D – mm Inside Diameter of the pipe

v – m2/sec Kinematic Viscosity (approximation, cP “centepoise” to m2/sec

multiply by 1 million for water)

L – m Length of the pipe

P – kg/m3 Density (SG, where 1 gram is 1 ml the n SG=1

Specific Gravity x 1000)

Pipe Fitting Component

Round the corner of a Tee T1 = 1

Past a side opening of a Tee T2 = 3

Back into line from a side opening in a Tee T3 = 1

Rounded corner 90° elbow (Long Rad. or L.R.90) E1 = 2

Abrupt 90° elbow ("hard" 90 or Machined "L") E2 = 9

Gentle 45° elbow (Bends &/or "5D" 90) E3 = 2

Estimating: dP @ peak of flow fluctuations

To find the increase in pulsation from flow fluctuation, assume max. Fluctuation from simplex pump is 3.25 x steady state Q. Divide 3.25 Q by “F” number for your pump type. Add the result to your steady state Q. Run the formula with your increased Q. Deduct steady state dP from this new dP. The difference is pulsation dP.

Effective Length of Pipe System

Leff = L + (0.0667 x D x T1) + (0.0209 x D x T2) + (0.0667 x D x T3) + (0.0327 x D x E1) + (0.0681 x D x E2) + (0.0144 x D x E3)

Figures applied for E and T are averages from tests