Formulas, Laws, Conversions and Related Data

System Head = total discharge head – total suction head

H = h_d – h_s

h_d = h_sd + h_pd + h_fd	h_s = h_ss + h_ps = h_fs
where:
h_d = total discharge head	h_s = total suction head
h_sd = discharge static head	h_ss = suction static head
h_pd = discharge surface pressure	h_ps = suction surface pressure
h_fd = discharge friction head	h_fs = suction friction head

Available NPSH is “the difference between the total suction head and the vapor pressure of the liquid, in feet of liquid, at the suction flange.”

h_sv = h_sa – h_ypa
where:

h_sv = available net position suction head, in feet of liquid

h_sa = total suction head, in feet of liquid, absolute

h_ypa = vapor pressure of liquid at suction nozzle, in feet of liquid, absolute

Head (ft.) = psi x 2.31 / sp. gr.

PSI = head (ft.) x sp. gr. / 2.31

Lbs./sq. in. = In. of Mercury x .491
Lbs./sq. in. = Atmospheres x 14.7

mm hg. = Atmospheres x 760

Centistokes x 4.64 = SSU₍_approx.)

Centipoise Sp. Gr. = Centistokes

Gallons per minute (GPM) x 3.785 = Leters per minute

°C = 5/9 (°F – 32)

°F = 9/5°C + 32

sp. gr. = weight of liquid
sp. gr. = weight of water

weight of water = 62.4 Lb./cu.
weight of water = 8.3 Lb./gal.

BHP = GPM x TDH x sp. gr.
BHP = 3960 x Eff.

BHP = GPM x PSI
BHP = 1715 x Eff.

KW = 0.746 x H.P.

Torque = (Ft. Lb.) = HP x 5260
Torque = (Ft. Lb.) = RPM

HP = E(volts) x I(Amps) x Eff. X P.F. x 1.732
HP = E(volts) x I(Amps)746

I(amps) = HP x 746
I(amps) = E(volts) x Eff. X P.F. x 1.732

Material[Code]
Temperature Limits

Modified Polytetrafluorethylene [TM]
Low: -100 °F (-73 °C) High: 300 °F (149 °C)

Viton [VA]
Low: -20 °F (-29 °C) High: 400 °F (204 °C)

Perfluoroelastomer (Kalrez) [KAL]
Low: -36 °F(-38 °C) High: 550 °F (287 °C)