Below are some of the most common boiler and steam conversions between units of measure. This is meant to be a helpful guide for quick converting of units. The conversions are generally accepted rules but due to the wide variety of product variance the calculations should be verified with original manufacturers specifications or system engineer. Roth Pump is not responsible for any errors in use of the calculations below. Proper sizing of pumps, condensate units, and boiler feed water can greatly reduce installed costs and overall systems energy factor. While most condensate return pump manufacturers triple the condensate rate of their condensate return pumps due to flow loss at higher temperatures Roth Pump preferably sizes our condensate unit pump rate a double the actual condensate rate due to the regenerative pumps ability to handle hotter water more reliably than that of a typical centrifugal pump. This allows the condensate to return at hotter temperatures to the boiler and provides an instant return on the initial investment.

PSI = Pounds per square inch - The pressure resulting from a force of one pound-force applied to an area of one square inch.
TDH = Total dynamic head - The total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe.
EDR = Equivalent Direct Radiation - EDR was originally a measure of the actual surface area of radiators. As radiator (and later convector) design became more complicated and compact, the relationship of actual surface area to EDR became arbitrary. Laboratory methods based on the condensation of steam allowed for very accurate measurements.
GPM = Gallons Per Minute - GPM is a measure of how many gallons of water flow out of your system each minute.
BHP = Boiler Horsepower - The boiler’s capacity to deliver steam to a system.
LB / HR = Pound per hour - Mass flow rate. It is particularly useful when dealing with gases or liquids, as volume flow varies more with temperature and pressure.
BTU / HR = measuring energy per unit time - Equal to 1 BTU being output in an hour.
MBH = Thousand BTU's per hour.
BTU = British thermal unit -The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
Bar = Metric unit of pressure.
M3/H = Cubic millimeters per hour - flow rate measuring unit.
FT3 = Cubic foot - The volume of a cube with sides of one foot (0.3048 m) in length.