BarishPump.com

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# 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.

 Suction Lift:NPSH = ha – hv – hs – hl Flooded suction:NPSH = ha – hv + hs – hl ha = the absolute pressure in feed of liquid on the surface of the supply liquid hv = the vapor pressure of the liquid being pumped expressed in feet of head hs = the height in feed of the supply liquid surface with respect to the pump inlet hl = 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. NPSHA must exceed NPSHR.

## Affinity Laws

Centrifugal Pumps

 For constant speed: D1 D2 = Q1 Q2 = √H1 √H2 BHP1 = (D1)3 BHP2 = (D2)3

For constant impeller diameter:

S1
S2
= Q1
Q2
= √H1
√H2

BHP1 = (S1)3
BHP2 = (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 = (3.937x10-2) 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 = (760-y) mm Hg absolute z PSIG = (z + 14.7) PSIA w PSIA = (w-14.7) PSIG

## PUMPING POWER FORMULA

 Centrifugal pumps: Brake hp = gpm x Hft 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)
 ft2 / sec = Centistokes x 1.07639 x 10-5 Centistokes = ft2 / 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