# Terms, Technology, and Formulas

## Kirkwood Formula Converter

### Download Here

## Download Here

## Mixing Fundamentals – Terminology and Formulas

## Motor Terms

**AMPERE:** A unit of intensity of electric current being produced in a conductor by the applied voltage.

**FREQUENCY:** The number of complete cycles per second of alternating current; e.g., 60 Hertz.

**HORSEPOWER:** The rate at which work is done. It is the result of work done (stated in foot-pounds) divided by the time involved.

**INERTIA:** The property of physical matter to remain at rest unless acted upon by some external force. Inertia usually concerns the driven load.

**MOTOR EFFICIENCY:** A measure of how effectively the motor turns electrical energy into mechanical energy. Motor efficiency is never 100% and is normally in the neighborhood of 85%.

**POWER FACTOR:** The ratio of the true power to the volt-amperes in an alternating current or circuit or apparatus.

**SERVICE FACTOR:** A safety factor in some motors which allows the motor, when necessary, to deliver greater than rated horsepower.

**SYNCHRONOUS SPEED & SLIP:** The speed of an a-e motor at which the motor would operate if the rotor turned at the exact speed of the rotating magnetic field. However in a-e induction motors, the rotor actually turns slightly slower. This difference is defined as slip and is expressed in percent of synchronous speed. Most induction motors have a slip of 1-3%.

**TORQUE:** That force which tends to produce torsion or rotation. In motors, it is considered to be the amount of force produced to turn the load. It is measured in lb.-ft.

**VOLTAGE:** A unit of electro-motive force. It is a force which, when applied to a conductor, will produce a current in the conductor.

## Basic Formulae and Symbols

PUMP SYMBOLS

GPM = gallons per minute

Lb = pounds

Hr. = hour

Sp. Gr. = specific gravity

H = head in feet

psi = pounds per square inch

In. Hg. = inches in mercury

hv = velocity head in feet

V = velocity in feet per second

g = 32.16 ft./sec.2 (acceleration of gravity)

A = area in square inches

I.D. = inside diameter in inches

BHP = break horsepower

Eff. = pump efficiency expressed as a decimal

N = speed, RPM

Ns = specific speed

Nss = suction specific speed

D = impeller in inches

NPSH = net positive suction head

NPSH^ = net positive suction available

Pa = atmospheric pressure in psia

Pvp = vapor pressure in psia

w = specific weight of liquid in pounds/cu. ft.

hs = total suction head ft.

Q = capacity in GPM