Diaphragm Expansion Tanks

Temperature in degrees Fahrenheit and pressure in psig

• initial temperature 50^oF
• initial pressure 10 psig
• maximum operating pressure 30 psig
• safety factor aprox. 2
• acceptance factor aprox. 0.5

The diagram below can be used to estimate the tank volume and acceptance volume of a diaphragm expansion tank at low temperatures.

For initial and maximum pressures different from above - multiply the tank size with the a correction factor estimated from the diagram below:

Temperature in degrees Celsius- pressure in kPa

• initial temperature 10^oC
• initial pressure 70 kPa
• maximum operating pressure 200 kPa
• safety factor aprox. 2
• acceptance factor aprox. 0.5

The diagram below can be used to estimate the tank volume and acceptance volume of a closed expansion tank at low temperatures.

For initial and maximum pressures different from above - multiply the tank size with the a correction factor estimated from the diagram below:

Temperature ^oC
K
^oF

Length m
km
in
ft
yards
miles
naut miles

Area m²
km²
in²
ft²
miles²
acres

Volume m³
liters
in³
ft³
us gal

Weight kg_f
N
lbf

Velocity m/s
km/h
ft/min
ft/s
mph
knots

Pressure Pa
bar
mm H₂O
kg/cm²
psi
inches H₂O

Flow m³/s
m³/h
US gpm
cfm