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Classes
	Syllabus
1	Intro. to the Course
2	Intro. to Gas and Oil Processing
3	Gas Processing Methods
4	Intro. to Water -Hydrolic Cycle
5	Intro. to Water -Part 2
6	Power Generation/ Cogeneration
7	Electricity Transmission
8	8 Missing
9	9 Missing
10	10Missing
11	Chemical, Reagents,Tools, Rigging
12	12 Missing
13	Land Use and Reclamation
14	Instrumentation and Drawings
	**** Final Exam*****
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	Resources
	Staff E-mail
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Objectives

1. Describe Instrumentation in Industry
2. Describe Drawings
3. BTMOSC
4. Basic Math Continued

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Safety Topic-Welding, Cutting, and Brazing

Whenever welding, cutting, or brazing operations are going on, everyone involved must take precautions to prevent fires, explosions, or personal injuries from exposure to toxic fumes, heat, and bright flames/arcs. There are three basic types of welding operations:

1. Oxygen­fuel gas welding joins metal parts by generating extremely high heat during combustion.
2. Resistance welding joins metals by generating heat through resistance created to the flow of electric current.
3. Arc welding joins or cuts metal parts by heat generated from an electric arc that extends between the welding electrode and the electrode placed on the equipment being welded.

Welding safety program guidelines

A good way to set up your training program is to incorporate relevant elements from your company-welding plan. Typical elements of a company welding plan usually includes:

1. Person responsible for safety in welding operations.
2. Job hazard assessment for welding operations. Common hazards include: health hazards from fumes and gases, radiation hazards, fire hazards, noise hazards from some equipment, and electrical hazards.
3. Special procedures for equipment used, such as: care of cylinders for oxy/fuel welding, ventilation systems set up for welding operations, fire prevention methods including fire watches, making sure that manufacturer instructions are followed.
4. Engineering controls (shields for welding areas, space from combustibles, etc.)
Personal protective equipment.

Welding hazards

Welding hazards vary, depending on the facility, equipment, number of workers present, and the job at hand. Discuss the dangers specific to your welding operations: Some examples are:

Damage to eyes and skin from continued or repeated exposure to ultraviolet and infrared rays produced by electric arcs and gas flames.

Toxic gases, fumes, and dust that may be released during welding and cutting operations.

Fire hazards from welding or cutting near or on combustible or flammable materials, dust, vapor, liquid or floors (use proper fire protection, issue hot-work permits for work in hazardous areas).

Explosion hazards (dust, fumes, gases, vapors---adequately ventilate the work area).

Safe work practices

Here are a few practices for working safely that apply in many situations. .

 

Keep floors clean by putting electrode or rod stubs in an appropriate container.

Keep floors clear of tripping hazards; store tools safely.

Do not arc or resistance weld while standing on damp surfaces.

Use shields to protect nearby employees doing other jobs.

Fire watch
Our company must designate an employee as a fire watch during welding or cutting operations. Fire watchers will:

Have fire-extinguishing equipment readily available and be trained in its use.

Watch for fires in all exposed areas.

Try to extinguish fires only when obviously within the capacity of the equipment available, or otherwise sound the alarm.

Housekeeping

Keep welding areas free of combustibles. Proper storage of compressed gas cylinders is also an element of fire prevention and could be addressed under the topic of housekeeping.

Employee training

There are no specific OSHA training requirements for welders and welding. However, OSHA can cite a company under the General Duty Clause which says: Employers must furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause, death or serious physical harm to his employees. Having welders that have not been trained would probably meet the requirements for a General Duty Clause citation. The best scenario would be to have certified welders.

If you do cutting and welding on the job, be sure to become familiar with your companys "hot work" permit system.

Where to go for more information.

29 CFR 1910.252 through .255

Instrumentation is used in industry to monitor and/or control industrial processes.

Modern industry could not exist without instrumentation. In a refinery, instruments control dozens of process variables. Without instrumentation it would take dozens of workers, each of whom monitored one or two items to make the refinery work. Even then, they would probably be too slow to do an effective job.

The simplest instrumentation is a status indicating system. For example a high level switch turns on an alarm to alert the operator that a tank is full.

Instrumentation can not only report status, it can control the process itself. Systems that control the process are referred to as loops.

Features of Loops

1. A process variable is converted to a signal which is sent to a controller
2. The controller has a setpoint which it compares to the process
3. The difference between the process and the setpoint is called the error
4. The controller moves a control element (valve) to eliminate the error
5. The process then will match the setpoint because of the error correction.

Picture 14-02 control..

There are two types of control, modulated and on/off.

Modulated.

The controller modulates or varies the control element. For example a valve which can be placed in any position between full open and full closed

On/Off

The controller can only turn the control element on or off. For example a solenoid valve which can only be full open or full closed. Another example, the electric heat thermostat in a house turns the heat on or off.

Slide 14-2 is a diagram of a simple control loop. This loop controls a boiler which heats crude oil to a temperature of 400 degrees. The temperature sensor sends the temperature to the controller which compares it to the setpoint. If the process is below the setpoint the controller will move the fuel valve a little more open to add fuel. If the process is above the setpoint the controller will move the valve a little more closed to subtract fuel. This is called a direct acting loop because the valve goes open to increase the process. In a reverse acting loop the valve would go closed to increase the process. Of course, that would not work in this particular application .

An important point: The valve will almost never be all the way open or closed. In fact, the valve might be at 50% for a long period of time if the process is stable. Then assume a change such as a greater flow of crude through the heater. This would cause the fuel valve to open perhaps to 55% so as to heat the additional crude that is now flowing in the system.

Live zero Analog loops use electrical current to send the sensed process to the controller. Normally this would be a current of 4-20 milliamps. 4 ma would be zero percent and 20 ma would be 100 percent of the process range. Why did industry pick 4 ma as the zero percent value? To distinguish between a zero percent value of the process and a failure in the loop itself. Current is used because current is equal everywhere in a simple series circuit. Voltage is not used in loops to sensors and control elements because voltage drops would cause inaccuracies. Once the signal finds its way to the control panel where wire runs are short and voltage drops are insignificant the current signal 4-20 ma is converted to a voltage for easier handling (1-5 volts =0 to 100%).

Sensors can be categorized into four basic groups

Level-Detect levels in tanks, process vessels, hoppers, etc., ultrasonic, head pressure, tape and float

Pressure-Pressure is measured in pipes, vessels etc. note pressure across an orifice is a common method of measuring flow.

Flow-Measured in liquid and gas pipelines, orifices, vane meters, positive displacement meters.

Temperature-Thermocouples, rtd's, capillary bulbs, infrared

Technologies-There are three technologies used to implement control loops. Many control loops use combinations of these technologies.

Electronic-Use electrical signals and computers, may be digital or analog, some functions might be implemented in software, others in hardware.

Hydraulic-Use hydraulic systems, typically very large valves are controlled hydraulically because of the large forces required.

Pneumatic-Uses compressed air or vacuum , sensors, controllers and actuators are less expensive than other technologies.

Drawings-Drawings are used in the plant to facilitate operations, maintenance and modification. The technical knowledge needed to run the plant should be contained in the drawing set.

Without the drawings, it would be difficult to explain or understand the processes that take place in the Process Industry and it would be even more complicated to try and make repairs.

The purpose of process systems drawings:

Used by Process Technicians to understand or explain a process
Used by Process Technicians to repair equipment and understand relationships
Used by Process Technicians to become familiar with the process in a safe environment
Provides a Process Technician with visual representation of the process and equipment

All drawings have certain functions in common:

Simplify - Drawings simplify complicated processes by using symbols to represent components.

Explain - Drawings explain how all the parts or components of a system work together. A drawing can clearly and quickly show the details of a system that might otherwise take many written pages to explain.

Standardize - Drawings standardize information. Each industrial drawing has its symbol that represents the component. These symbols (with some subtle changes) are used all over the world. If a Process Technician knows the symbols, this knowledge will allow them to interpret drawings at any jobsite.

Common Components of Drawings

All process system drawings have certain common components that are universal to drawings. These components include:

Legend

This is a table that explains or defines all the information of a drawing. The information defined in this table includes:

* Symbols
* Abbreviations
* Numbers
* Tolerances
* Other

Title Block

These are usually located in the bottom right-hand corner of drawings. The information included in the title block includes:

Drawing number
Revision number
Drawing title
Sheet number
Signatures
Tolerances

Application block

Dimensions
Shapes
Descriptions
Relative position
Types of material
Functions

Different Drawing Types and Their Use

Block Flow Drawings
Process Flow Drawings (PFD)
Piping and Instrument Drawings (P&ID)
Electrical Schematics
Isometrics

Block Flow Drawings

Theses are the simplest drawings used in the Process Industry. They provide a very general overview of the process and contain very few specific details. Block Flow drawings represent sections of the process as blocks and they show the order and relationship between sections using flow arrows. Block Flow drawings are useful in getting a high level initial understanding of a process.

Process Flow Drawings (PFD)

Show the major pieces of equipment and instrumentation along with process conditions of pressure, flow, and temperature. May also include a material balance including compositions of the streams.

Are used to trace the process flow through a chemical plant or refinery.

Show all the major pieces of equipment and piping, temperatures, and pressures at critical points, and the flow of the process.

Represents with symbols, a fluid system and the equipment associated with a fluid system.

Are valuable to Process Technicians because they show how the process works and the steps associated with the process.

Provide critical information about:

The major instruments in each area of the plant and where they are located.
The kind of equipment and the type of piping used in each stage of the process.
The utilities used in a process.

PFDs give information about the following types of equipment:

Vessels
Heat exchangers
Pumps
Compressors
Heaters
Instruments
Valves
Piping

Piping and Instrument Drawings (P&ID)

Shows the detailed piping instrumentation and equipment along with design information such as piping size and specifications.

P&IDs include:
All the equipment used
All the instrumentation
Size and type of pipe
Design conditions of the equipment

Contain information about the ways in which piping sections are connected and the instruments associated with the system. P&IDs describe the way in which fluids are directed and controlled. The majority of information about the piping systems comes from instruments that help control and monitor the system. It is critical that Process Technicians know where in the system the instruments are located.

Show the equipment in detail and give information on piping dimensions and types. They show all the instruments used and the operating conditions of all the steps in a stage. Provide valuable information about maintenance and repair work on piping systems.

Utility Flow Drawings (UFD)

Show the piping and major instrumentation used to operate the utilities in a process.

UFDs are basically a P&ID drawing for utilities.

Show the way in which utilities are connected to the process equipment for service.

Typical utilities include:

Steam
Condensate
Fuel oil
Instrument air
Utility air
Cooling water
Drains
Process and reclaim water
Flares

Electrical Drawings

Most equipment used in the Process Industry is powered by electricity. For this reason, it is important that a Process Technician understand the system, how it works, and how it is maintained.

Electrical drawings contain information on how electrical components and devices are connected to provide electrical functions.

Wiring Diagrams Show the interconnecting wiring between field and control room devices including routing and cable numbers

Are intended to show the physical layout of the wires.
Used when specific information is needed about the way in which components are connected..
Used when information is needed about where components are physically located .

Schematics

Show the electrical connections between all components in a circuit or device.

Used to determine a troubleshooting strategy for the circuit.

Used to locate test points in a device or circuit.

Shows expected voltages for troubleshooting .

Used to see how current flows between two or more circuits that form a large system.

Isometrics

Isometric drawings are engineering drawings that are often used with new construction of a unit.

Process Technicians are rarely exposed to isometric drawings unless a new unit is being built.

Isometrics are used to show objects, as they would appear to the viewer.

Isometrics show:

Three sides of the object that can be seen.
The object appears at a 30-degree angle with respect to the viewer.
All vertical lines appear vertical and are parallel to one another.
All horizontal lines appear at a 30-degree angle and are parallel to one another.

Basic Terms

Basic Terms of Maintenance, Operations and System Components

Actuator A device which accepts an electric, hydraulic or pneumatic signal and positions itself accordingly

Analog In industry, a signal which constantly variable along the spectrum of 0 to 100%

Control Element A valve, damper, or other device which is commanded to a specific position by a controller. The control element is the final element in a control loop.

Control loop A control system for a process with feedback

Controller A device which compares a process to a setpoint and develops a control output signal

Digital In industry a signal which is represented by a number

Error In instrumentation, the difference between a process and a setpoint as measure by a controller

Flow Gallons per minute, etc

Hydraulic A system which uses liquid as a sensing or control medium

Infrared A longer wavelength of light, typically heat, which can be remotely sensed to determine the temperature of an object

Isometric A drawing which is in 3 dimensions

Legend This is a table that explains or defines all the information of a drawing.

Live zero In instrumentation the practice of defining a zero signal with a definite value of 4 ma or 1 volt

Modulated In industry a process which is varied gently as opposed to on/off

Orifice In industry, a plate with a calibrated hole drilled in it through which a liquid or gas flows. The pressure difference across the plate can be used to determine the flow

Pneumatic A systems which uses air as a sensing or control medium, includes vacuum

Pressure The energy exerted by a gas or liquid against a container

Process Variable A physical property in an industrial plant which is measure by a sensor

RTC A thermoelectric device often constructed from platinum whose resistance is proportional to temperature.

Schematic A drawing of an electrical appliances internal components and wiring

Sensor A device which detects and quantifies a physical property

Setpoint A desired process condition, usually a desired pressure, flow, level, or temperature

Solenoid valve An on/off valve drive by a simple electromagnetic mechanism

Tape and float A level measuring device which uses a float suspended on a tape, the tape is wound around a wheel which is connected to an electrical sensing element

Thermocouple A thermoelectric device consisting of two dissimilar metals joined so that a potential electrical difference generated between the points of contact is a measure of the temperature difference between the points.

Ultrasonic In industry, a device which uses sound waves to detect or quantify a process variable.

Wiring Diagram A drawing which shows the wiring interconnects between field and control room wiring.