(4) When you put volumes of measurement together with units of time, you have different

measures of flow rates. Some of the more common flow rates we will discuss throughout the course are:

gallons per minute, barrels per hour, and cubic feet per second.

b. Conversion of Flow Rates. Often, when working in the petroleum field, we are required to take a

flow rate that is given in one unit of measurement and convert it to another in order to solve a specific

problem. For example, we may be given a flow rate of gallons per minute but may have to convert that

unit of measurement to barrels per hour to satisfy a specific scenario. Luckily, most flow rate

conversions we are required to make have already been figured out mathematically and placed into FM

10-67-1, Appendix M. All you have to do is take the correction unit from FM 10-67-1 and multiply it

by your answer to convert the flow rate. However, there may be some cases in which a specific flow

rate is not listed in that reference manual. Therefore, we need to discuss how to perform these

conversions so that you can understand how they were calculated.

(1) Let us take an example and solve it together. Problem: You re operating a hose line

system, and you have a meter in-line. You have received 500 gallons over the past two minutes, but

your supervisor needs to know how many cubic feet per second it equals. To solve, you follow this

order:

(a) The first requirement in this example is to convert the time down to a minute of

measurement. Since we are dealing with two minutes, divide by two to convert to a by-minute unit of

measurement. Thus, 500 gallons over two minutes convert to 250 gallons per minute.

(b) Using FM 10-67-1, Appendix M, note that converting from gallons per minute to

cubic feet per second requires multiplying your answer by 0.002228. By multiplying this factor by the

250 gallons per minute, we can determine that a flow rate of 250 gallons per minute is equal **to 0.557**

(2) Where do the conversions come from? As was previously stated, it is important to

understand where these conversion factors in FM 10-67-1 come from, since not all possible flow rates

are listed in that reference.

(a) All units of measurement are convertible, as long as you know their characteristics.

For example, most people do not know offhand that 1 hour equals 3,600 seconds. But, everyone knows

that 1 hour equals 60 minutes and 1 minute equals 60 seconds. By multiplying these two conversions

together, we can quickly determine that 1 hour equals 3,600 seconds.

(b) Looking at the previous example, the flow rate gallons per minute had to be

converted to cubic feet per second. How was this conversion derived? One of the first things to

remember is that whenever we have measurement units in a numerator or denominator, the only way to

cancel those units is to put them on the other side of the fraction.

(c) Starting with the flow rate gallons per minute, we can write that flow rate as a

fraction, gallons over minutes. This flow rate must be converted to cubic feet per second, or cubic feet

over seconds. Breaking these fractions down, we see that we are required to convert gallons to cubic

feet for the volume measurement, and minutes to seconds for the time measurement.

(d) Gallons can be converted to cubic feet by determining the number of gallons in a

cubic foot. That number is 7.48. So, if you start with your fraction gallons over minutes and multiply

that by

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