# Useful formula thread



## ILPlumber (Jun 17, 2008)

psi = 0.433 x feet head
feet head = 2.31 x psi
(note that 0.433 = 1 / 2.31)
1 BTU = heat required to raise 1 pound of water 1 degree F
BTU = 8.33 x gallons x deltaT
KW = BTU / 3412
Water weighs 8.33 pounds per gallon
Water weighs 62.4 pounds per cubic foot
There are 7.48 gallons per cubic foot
There are 448 GPM per CFS
HP = GPM x feet of head / 3960 x pump efficiency
I thought these were good to have around. They were in one of my trade mags. Thought I would share.

Do you have any formulas you carry with you? Put em here...


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## SlickRick (Sep 3, 2009)

My sole electrical formula. Watts divided by the volts give the amps, volts divided by the amps gives the ohms. If I could just remember the ohms on elements, I wouldn't have to use it every time. :whistling2:


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## SewerRatz (Apr 25, 2009)

To find the (T)ravel, (S)et, and (R)un of a 45º offset:

T= S x 1.414 if set is known to find travel
S= T x .707 if travel is known to find set
R= S x 1.00 Set and Run are = to each other on a 45º offset
S= R x 1.00 Set and Run are = to each other on a 45º offset
T= R x 1.414 
R= T x .707

To find the (T)ravel, (S)et, and (R)un of a 22½º offset:

T=S x 2.613
S=T x .383
R=S x 2.414
S=R x .414
T=R x 1.082
R=T x .924

To find the (T)ravel, (S)et, and (R)un of a 60º offset:

T= S x 1.155
S= T x .866
R= S x .577
S= R x 1.732
T= R x 2.00
R= T x .500


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