Pressure
Pushing down on me
Pressing down on you
No man ask for

("Under Pressure," by David Bowie and Queen, 1981-82)

 

THE PTOA PROCESS VARIABLE PRESSURE FOCUS STUDY AREA BEGINS!

Brilliant PTOA Readers and Students ... meaning those who are reading the PTOA Segments in the intended, sequential order ... have completed the PTOA Process Variable Temperature Focus Study Area.

Those brilliant PTOA Readers and Students now core-competently understand

• The fundamentals of the PV Temperature, including:
  1. How increasing Temperature increases the energy content of matter and causes that matter to change from a solid to a liquid and then a gas (and vice versa when giving up that energy to the immediate surroundings).
  2. The difference between Temperature and Heat.
  3. Methods of Heat Transfer - Conduction, Convection, and Radiation.
• Industrial Process uses of the PV Temperature.
• Industrial Process Equipment and Technology used to increase and decreases the PV Temperature.
• Industrial Process Equipment used for heat exchange and the resulting cost effectiveness/environmental benefits realized with heat exchange.
• Instrumentation used for Detection and Measurement of the PV Temperature and related ISA symbols.

 

Now it is time to move on to ...

THE PTOA PROCESS VARIABLE* PRESSURE
FOCUS STUDY AREA!

*Reminder: "PV" is shorthand for "Process Variable"

The PTOA PV Pressure Focus Study Area will follow a similar modus operandi to that used for PV Temperature instruction.

Spoiler Alert!

PTOA Readers and Students must keep their thinking caps on because the concept of "Pressure" is harder to comprehend than "Temperature."

All PTOA Readers and Students experience daily Temperature changes and can thus more easily understand the concepts of increasing and decreasing the PV Temperature.

However, almost everybody goes about their day experiencing the same Ambient Pressure ... 14.7 psia (1 Atm) at sea level ...  somewhat less for those living at higher elevations and somewhat higher for those living below sea level (aka Death Valley, CA).

In the Process Industries, increasing the PV Pressure of a gas or liquid ...  aka "fluids"... takes a lot of energy and hard work! The category of industrial equipment called "Rotating Equipment" is required to increase the PV Pressure above Atmospheric Pressure. Energy and work is also required to create a PV Pressure below Atmospheric Pressure. Incidentally, any Pressure less than 14.7 psia (1 ATM) is a "Vacuum Pressure."

Any PV Pressure on Earth that is different than local ambient Pressure must be generated using a Pump (for liquids) or a Compressor (for gases and vapors).  And ... wouldn't you know it!... there aren't too many marketable products made by the Process Industries at the ambient Pressure of 14.7 psia (1 ATM).

And ... guess what?

The Pump or Compressor that is required to create the PV Pressure cannot spin or rotate all by itself!

A Driver/Prime Mover must be coupled with the Pump or Compressor to provide the horsepower needed to spin or reciprocate or rotate the shaft of the Pump or Compressor.

Wait! Wait! There's even more important stuff required to change the PV Pressure from 4.7 psia (1 Atm):

The Driver/Prime Mover that is coupled to the Pump or Compressor has dozens of moving metal parts which must be constantly lubricated to prevent friction from causing wear and unplanned breakdowns.

Furthermore, the coupled Rotating Equipment must be sealed off from the local environment ... not just to prevent leakage from the Pump and Compressor but to also prevent contaminants from entering the Rotating Equipment and contaminating the lubrication oil!

Gee Whiz! Creating a change in the PV Pressure from 14.7 psia (1 ATM) is a lot more complicated than the technology required to create a change in the PV Temperature!

No time like the present to start the journey of learning the PTOA PV Pressure Focus Study Area content.  And it is too long of a journey to be broken up by jargon recaps and PTOA Segment updates! That statement does not excuse PTOA Readers and Student from learning the correct industrial lingo.

Every PTOA Reader and Student who has gotten this far in their Process Tech self-study already has what it takes to pay attention to the italicized and bold emphasized words in each PTOA Segment!

The hard work PTOA Readers and Students devote to understanding the role that PV Pressure plays in Process Industry will be worth it! Every potential Process Technology employer wants to hire Process Operators who are familiar with the form and function of expensive Rotating Equipment because these are the Process Operators who will keep the Rotating Equipment online, ergo making money! So... ONWARD!  

Here's the PTOA PV Pressure Focus Study Area Parts 1 through 4 instruction Outline:

 

THE PTOA PV PRESSURE FOCUS STUDY AREA 
PART 1: THE INTRODUCTION TO PV PRESSURE FUNDAMENTALS

• 

  Pressure is simply a Force (F) applied over a Surface Area (A).

  Industrial Applications of the PV Pressure.

• P is For Pressure! - the ISA Symbols for PV Pressure. 
• The Definitions of Pressure: P = Force/Area and Gravitational Force F=(Mass) X (Acceleration of Gravity).
• The Difference between a Pound of Mass and a Pound of Force.

• The Overlooked Assumptions that Allow Equating a  a Pound of Force to a Pound of Mass.

• How to Calculate the Hydrostatic Pressure of Any Liquid in a Container.

• Density and "Relative Density" (aka Specific Gravity).

• Dams, Tanks, and Vessels are Examples of (Hydraulic) Head Pressure. 
• Common Conversion Factors Used in Process Industry for SI and English Units.
• The Differences Between Absolute, Atmospheric, Gauge, and Vacuum Pressures and their respective industrial applications.

• 

  A "Vacuum Pressure" is less than Atmospheric Pressure (14.7 psia=1 ATM).

  Vacuum Pressures, Creating Vacuum Pressures, Industrial Uses of Vacuum Pressures.

• Predictable Gas and Liquid Behavior Called "Laws."

• PTOA PV Pressure Fundamentals Review.

 

 

Dang! That's A LOT of STEM Topics to get under the belt!

STEM Topics relate how the fundamentals of Science and Math are incorporated into Technologies and Engineering.

Process Technology is jammed packed with the industrial application of STEM topics!

 

 

THE PTOA PV PRESSURE FOCUS STUDY AREA
PART 2: THE INTERRELATIONSHIP OF THE PV PRESSURE WITH PV TEMPERATURE, PV FLOWRATE, AND PV LEVEL 

Life is all about relationships!

The PV Pressure/PV Temperature Relationship

• • PV Pressure Impact on Boiling Point Temperature, Freeze Point Temperature, Condensation Temperature.
  • Local Atmospheric Pressure and Boiling Point Temperature.
  • Process Industry Examples that Use the PV Pressure/PV Temperature Relationship.

 

 

The PV Pressure and PV Flowrate Relationship

• • 

    In any flowing fluid, when the Fluid Velocity increases, the sensed Pressure in the line Decreases ... and vice versa! Pressure and Fluid Velocity Swap!

    The PV Pressure ↔ Fluid Velocity Swap.

  • "The Power of the Swap" makes it possible to infuse the PV Pressure into a flowing liquid!

• • Delta P (aka ΔP, dp, Pressure Drop, Pressure Gradient) ... No Delta P=No Flow.
  • Process Industry Examples that Use the PV Pressure/PV Flowrate Relationship.

 

 

• 

  The greater the level of liquid, the greater the hydrostatic Pressure sensed at the bottom of the tank!

  The PV Pressure/PV Level Relationship

  • The Hydrostatic Head (and potential Pressure Energy) of Stored Liquids.
  • The PV Pressure/PV Level Relationship and Liquid/Vapor Equilibrium.
  • Process Industry Examples that Use the PV Pressure/PV Level Relationship.

 

 

 

 

 

• The Relationship Between Rotating Equipment and Process Operators.

 

• Review of the Physical Properties of Fluids (Density, Specific Gravity, Etc.).

 

 

THE PTOA PV PRESSURE FOCUS STUDY AREA 
PART 3: DEEP-DIVE INTO A CENTRIFUGAL PUMP ILLUSTRATES
HOW PRESSURE ENERGY CAN BE INFUSED INTO FLOWING LIQUIDS

• Introduction to Pumps and their ISA Symbols.
• The Typical Pump Installation Set-Up.
• Where Does the PV Pressure Go? Friction Causes Fluid Pressure Loss.
• Interpreting the Centrifugal Pump TDH vs Capacity Characteristic Curve.
• Hydraulic Head and Centrifugal Pump Performance Curves
• Determining the Optimal Performance Range of a Centrifugal Pump from Performance Curves.
• Affinity Laws for Impellers.
• Cavitation Defined and Cavitation Prevention. 
• How Centrifugal Force Increases the Pressure Energy in Non-Compressive Fluids (aka, Liquids).
• The Pumping Side and the Power Side of a Centrifugal Pump (aka Why Drivers are Needed).
• The Volute's Important Role Building Up the PV Pressure Via Centrifugal Action.
•  Impeller and Volute Modifications that enhance infusing Pressure Energy into Pumped Liquids.

 

 

 

THE PTOA PV PRESSURE FOCUS STUDY AREA
PART 4: THE COMMON HARDWARE OF ROTATING EQUIPMENT
AND HOW OPERATORS TAKE CARE OF IT

• PTOA Focus Study on Tribology: The Relationship of Friction, Wear, and the Importance of Lubrication Oil Systems.
• Stuffing Box Internals.
• PTOA Focus Study on Bearings and Bearing Seals.
• Couplings.
• Definition of Torque and How Gears Transmit/Adjust HP.

 

 

 

 

STAY TUNED!

THERE'S MORE TO COME!

THE PTOA PV PRESSURE FOCUS STUDY AREA INSTRUCTION OUTLINE PARTS 5-8 ARE FEATURED IN THE NEXT PTOA SEGMENT ...

 

 

©2016 PTOA Segment 0138
PTOA Process Variable Pressure Focus Study Area Instruction Outline Parts 1-4

You need to login or register to bookmark/favorite this content.