
Your shopping cart is empty!
Calculators
Calculators will help you to properly size up your pump, piping and fittings. With these tools, you can determine suction loss, friction loss, specific gravity, along with the useful conversion tables.
Head & Pressure Formula
Head in feet  =  (Head in psi) x 2.31 (Sp. Gr.) 
Head in psi  =  (Head in feet) x (Sp. Gr.) 2.31 
Net Positive Suction Head
Suction Lift: NPSH = h_{a} – h_{v} – h_{s} – h_{l} 
Flooded suction: NPSH = h_{a} – h_{v} + h_{s} – h_{l} 
h_{a} = the absolute pressure in feed of liquid on the surface of the supply liquid h_{v} = the vapor pressure of the liquid being pumped expressed in feet of head h_{s} = the height in feed of the supply liquid surface with respect to the pump inlet h_{l} = suction line friction losses express in feet of head These calculations yield the available net positive suction head for a given system. This must be compared to the required net positive suction head NPSHR calculated by the manufacturer. NPSH_{A} must exceed NPSH_{R}. 
Affinity Laws
Centrifugal Pumps
For constant speed: 

D_{1} D_{2} 
=  Q_{1} Q_{2} 
=  √H_{1} √H_{2} 
BHP_{1} = (D1)^{3} BHP_{2} = (D2)^{3} 
For constant impeller diameter:
S_{1} S_{2} 
=  Q_{1} Q_{2} 
=  √H_{1} √H_{2} 
BHP_{1} = (S1)^{3} BHP_{2} = (S2)^{3} 
D = Impeller diameter in inches H = Head in feet
S = Speeds in RPM Q = Capacities in GPM
BHP = Brake Horsepower
Vacuum Pressure Equivalents:
1 Atmosphere = 29.92 in. Hg = 760mm Hg = 14.7 psi 1 mm Hg = 1 Torr = (3.937x102) in. Hg = 1000µ Hg = 1.333 millibars 1 bar = 103 millibars = 106 microbars = 750.06 mm Hg 1 microbar = 0.75 micron 1 inch Hg = 2.54 x 101 mm Hg x in. Hg vacuum = (29.92–x) in. Hg absolute y mm Hg vacuum = (760y) mm Hg absolute z PSIG = (z + 14.7) PSIA w PSIA = (w14.7) PSIG 
PUMPING POWER FORMULA
Centrifugal pumps:  
Brake hp  =  gpm x H_{ft} x Sp. Gr. 3960 x Efficiency 
Rotary and reciprocating pumps:  
Brake hp  =  gpm x psi 1714 x Efficiency 
KW  =  pump bhp x 0.7457 motor efficiency 
GENERAL INFORMATION
1 HP = .746 KW or 746 Watts GPM = Bbls. / Hr. x 0.70 GPM = Bbls. / Day x 0.2917 One Barrel Oil = 42 Gallons 
VISCOSITY
Relationships
Centistokes  =  Centipoises Density 
(usually the same as specific gravity) 
ft^{2} / sec = Centistokes x 1.07639 x 10^{5} Centistokes = ft^{2} / sec x 92903.4 Approximate Conversions (50 < SSU ± 100) Centistokes = SSU x 0.226 – 205.3 / SSU (100 < SSU ≤ 350) Centistokes = SSU x 0.220 – 147.7 / SSU (SSU > 350 @ 100° F) Centistokes = SSU x 0.21576 (SSU > 350 @ 210° F) Centistokes = SSU x .021426 
FLOW
Lbs. Of Water / Hr x 0.002 = Gal Min.
Gal / Min. x 500 = Lbs of Water / Hr
Lbs of Fluid / Hr Specific Gravity 
=  Gal Min. 
Liter Min. x 0.264 = Gal / Min. (US) GPM x 3.785 = Liters / Min. Cu. Meters / Hr x 4.4 = Gal / Min. (US) Gal / Min. x 227 = Cu. Meters / Hr Kg of Water / Min. x 0.264 = Gal / Min. (US) Gal Min. x 3.8 = Kg of Water / Min. 
PRESSURE
Ft of Water x 0.433 = PSI PSI x 2.31 = Ft of Water Inches Hg. X 0.491 = PSI Inches Hg. X 1.133 = Ft of Water ATM x 14.7 = PSI ATM x 33.9 = Ft of Water Kg / Sq cm x 14.22 = PSI Meters of Water x 1.42 = PSI ATM x 760 = mm Hg. mm Hg. X 0.39 = Inches Hg. Bar x 14.5 = PSI Newton / Meter2 x 1 = Pascal PSI x 6.9 = kPa (Kilopascal) kPa x 0.145 =PSI 
VOLUME
Lbs Water x 0.119 = Gal Gal (Brit) x 1.2 = Gal (US) Gal x 128 = Fluid Ounces Cubic Ft x 7.48 = Gal Cubic in. x 0.00433 = Gal Gal x 3.785 = Liters Liter x 0.264 = Gal Cubic Meters x 264.2 = Gallons Cubic Meter x 1000 = Liters Liters x 1000 = Cubic Centimeters Cubic Centimeters x 0.338 = Fluid Ounces Fluid Ounces x 29.57 = Cubic Centimeters 
MASS
Gal of Water x 8.336 = Lbs Cubic Ft of Water x 62.4 = Lbs Ounces x 0.625 = Lbs Kilograms x 2.2 = Lbs Lbs x 0.454 = Kilograms Metric Ton x 2205 = Lbs 
MASS
Mils x 0.001 = Inches Meters x 3.281 = Feet Centimeters x 0.394 = Inches Millimeters x 0.0394 = Inches Microns x 0.0000394 = Inches 