Say the word and you'll be free.
Say the word and be like me.

("The Word," by the Beatles, 1965)

This is the first of a two-part series which recaps process industry jargon related to:

The Process Variable Temperature
Process Industry Schematics (P&IDs)
and Process Industry Automation.

 

HOW HOT IS HOT?

Starting to Focus on the Process Variable Temperature

Ambient Temperature: The temperature that surrounds you and that you would sense on your skin if you were naked.

Inside Ambient Temperature: The temperature that surrounds you when standing in a room. The inside ambient temperature can be manufactured by air conditioning or a room heater.

Outside Ambient Temperature: The temperature of the outside surroundings wherever you happen to be. The outside ambient temperature cannot be manufactured. The outside ambient temperature varies due to season. PTOA Readers and  Students will soon learn that the outside ambient temperature impacts processing conditions.

Temperature: A relative sense of hotness or coldness gauged by scales called thermometers.

Temperature Indicator (TI): An instrument that detects, measures and displays the temperature of stuff flowing through the pipes in a process facility. TIs look a lot like thermometers but their sensing elements must be protected from stuff flowing through pipes.

 

FOUR GREAT REASONS TO MONITOR TEMPERATURES

Why Process Operators Are Needed to Monitor Local Process Temperatures

Boiling: A change of state/phase change described by a liquid turning into a vapor  because of a temperature increase. Boiling differs from Evaporation because in boiling the bubbles of vapor form below the surface of the liquid.

Change of State/Phase Change: A change of state/phase change is a physical change in stuff caused by temperature increasing or decreasing. Stuff will change from a solid to a liquid to a gas when the temperature rises. Stuff will change from a gas to a liquid to a solid when the temperature decreases. In some cases stuff will skip steps and go from a solid to a gas and vice versa.

Changing the physical state of matter: A phrase found in text books that means stuff will change from solid to liquid to gas and back again depending on temperature changes. Refer to the above definition for Change of State/Phase Change.

Condenses/Condensation: A change of state/phase change described by a gas changing into a liquid due to a temperature decrease.

Desired Operating Temperature: The temperature of the stuff flowing though the pipes when it is where it should be to optimally convert feedstocks into products.

Evaporation: A change of state/phase change described by a liquid turning into a vapor  because of a temperature increase. Evaporation differs from Boiling because in evaporation the bubbles of vapor form above the surface of the liquid.

Freezing: A change of state/phase change described by a liquid turning into a solid due to a temperature decrease.

Melting: A change of state/phase change described by a solid turning into a liquid due to a temperature increase.

Yield:  There are several ways to define a yield. Sometimes there is an interest in knowing how much of a desired product was made compared to all the products made. The "% Yield of a Desired Product" would be determined by the below method:

Divide the amount of Desired Product (DP) by the Total amount of all Products (TP). The answer is multiplied by 100 so that the answer will be in a percent instead of expressed as a decimal fraction:

(DP)/(TP) * 100 = The % of Desired Product Made as a Percentage of Total Products Made.

Example of Yield Calculation:

Assume the container of mixed products shown in the graphic at the right weighs 100 pounds.

50 pounds of gasoline, 40 pounds of a mixture of diesel-heating oil-jet fuel-kerosene, and 10 pounds of resid (not shown in picture) are produced from the 100 pounds of mixed products.

The yield of gasoline is:

(50 pounds gasoline /100 pounds Total Products)
* 100 = 50%

Yield can be calculated in pounds (a weight basis) or in volume (a volume basis).  The above example of % Yield used pounds and is therefore a weight basis yield.

Sublimation: A change of state/phase change described by a solid turning directly into a gas due to a temperature increase. In this case the solid skips the step of becoming a liquid first.

 

DO YOU KNOW WHAT I MEAN?

Two Quick Jargon Lessons

Process Fluid/Process Stream: The fluid that is flowing through the pipes of an industrial process.

The term "process fluid" implies the stuff flowing through the pipes is a gas or a liquid or a mixture of both because both liquids and gases are fluids.

The term "process stream" implies the stuff flowing through the pipes could be in more than one phase.

Process Temperature: The temperature of the process fluid/process stream.

 

EVERY PICTURE TELLS A STORY DON'T IT?

Piping and Instrumentation Diagrams.

International Society of Automation (ISA): The group that standardizes ISA symbols used on P&IDs and PFDs.

PFDs, Process Flow Diagrams: A set of simplified process schematics that shows just the critical stationary and rotating equipment and strategic control loops needed for a process to convert feedstocks into desired products and by-products. Since the PFD is much less detailed than the P&ID, PFDs are helpful to the reader who just wants an overview of the process technology steps used to convert feedstocks  into products.

The front page of the PFD has the "Mass and Energy Balance." The Mass and Energy Balance shows step-by-step how the components in the feedstocks are gradually changed into the components that make up the desired products and by-products.

Piping and Instrumentation Diagrams (P&IDs). A detailed set of schematics that illustrates how every piece of stationary and rotating equipment is piped together and illustrates how the instrumentation and automatic controls interface with the process hardware to produce final products from feedstocks.

P&IDs are generated during the initial design phases of the plant and afterward become an important document that teaches generations of Process Operators about the multi million dollar process that they are responsible for.

Reading P&IDs: The process of interpreting the ISA symbols on a P&ID for the purpose of gaining a thorough knowledge of how the hardware and instrumentation are assembled together to convert feedstocks into products.

For example, the P&ID will show a P&ID reader a small detail...like where every high point and low point bleeder is located...and other information that is potentially time-saving knowledge.

Tag Name: The nomenclature defined by the ISA that assigns each piece of hardware and instrumentation a unique identifier.

The first letter of a tag name will define what variable is being controlled: T for Temperature, P for Pressure, F for Flowrate, and L for Level.

The second letter of a tag name (if there is one) will define the function of the instrument: I for Indicating, R for Recording, etc.

The third letter of the tag name will describe what the instrument is: C for Controller, I for Indicator, R for Recorder, etc.

The numbers of a tag name are assigned sequentially "as the feedstock flows through the process lines."

Instruments in the same control loop family will be assigned the same tag name number.

 

WHAT DO P&IDs HAVE IN COMMON WITH CRIME SCENES?

Analyzing a P&ID

Arrowhead (on a P&ID process flow line): The pointer on a P&ID process line that illustrates which way the flow is going.

Darker lines on P&IDs: These lines are used to represent process flow lines. Process flow lines are the pipes that have feedstock, intermediate products, by products, or final products flowing through them.

Lighter lines on a P&ID: These lines are used to represent instrumentation connections to equipment or process lines.

 

The next PTOA segment continues the recap of process industry jargon related to:

The Process Variable Temperature
Process Industry Schematics (P&IDs)
Process Industry Automation

 

©2015 PTOA Segment 00019
PTOA Process Industry Jargon Recap 1-1

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