Measurement Library

Western Gas Measurement Short Course Publications (2019)

Western Gas Measurement Short Courses

ADVANCED GAS QUALITY
Author(s): MAY LEW
Abstract/Introduction:
When you think of natural gas measurement you most likely think of meters or volume measurement. However, gas bills are in therms not flow rates like scf or Mcf. To determine therms we need to know the flow rates and billing rates (BTU). BTU is determined by measurements of other parameters like hydrocarbon composition, carbon dioxide, and nitrogen. But is that all that needs to be measured by a gas distribution company? In order to transport gas through pipelines and supply customers, other measurement devices may be needed to ensure an acceptable gas quality. Acceptable gas quality is specified in Tariffs or in contractual agreement between the utility and its gas suppliers. In this presentation we will go over the typical natural gas parameters that should be specified.
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Document ID: 07112C7C

Introduction to Basic Gas Laws
Author(s): Timothy Clark
Abstract/Introduction:
Throughout history there has been an accumulative effort that has led to the current day understanding of gas principles. Scientists like Joseph Louis Gay-Lussac, Amedo Avogadro, Robert Boyle and Jaques Charles laid the groundwork for the theories that became the Basic Gas Laws.
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Document ID: 7296E078

Combined Accuracy
Author(s): Rex C. Allen
Abstract/Introduction:
We use the term Combined Accuracy to define the error in both the meter and the instrument in a single figure. This figure also helps us stay within rules/regulations or Company policies requiring us to measure within a defined overall error tolerance. We all want to provide our customers with a bill that accurately depicts their usage, no more, no less. Using Combined Accuracy allows us to get there by accounting for known error in both pieces of our measurement equipment. The typical gas meter setup found in residential or low volume commercial customers consists of a standalone meter. Since there is only one measuring device, there is no combined accuracy calculation. The meter accuracy, by itself, dictates its measurement accuracy via the meters check proof. Combined Accuracy comes into play usually with your larger, high demand commercial applications where an Electronic Volume Corrector is employed with the gas meter. We now have two measurement devices working in tandem. With two measurement devices, we have two accuracy points to contend with.
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Document ID: 301F1FBE

Flexible Element Regulators
Author(s): REESE M. DAWES
Abstract/Introduction:
Flexible Element Regulators, also referred to as Unloading Design Regulators, utilize a rubber element that functions as both the actuator and valve of a self contained pressure regulator. This is in contrast to the more traditional style of regulators where a separate actuator, throttling valve and seat are used to regulate the pressure and provide shutoff. Traditionally in pressure control applications utilizing self-contained regulators, the restricting element of the regulator is a valve plug with an elastomer seat on the surface, which presses against a knife-edge orifice. The valve plugs function is to open and close in the flow stream when the flow demand fluctuates, and provide tight shutoff against the seat when no flow is required. This valve plug is coupled to a separate actuator component, which is actuated using pressure, and moves the valve plug to regulate and shutoff the flow stream (see Figure 1).
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Document ID: 7ABDCD38

FUNDAMENTALS OF FLOW COMPUTERS
Author(s): JOHN SWARTZ, TUSHAR SHAH
Abstract/Introduction:
The intention for this paper is to provide an overview of flow computers and how they integrate into the world of electronic gas measurement while utilizing the American Petroleum Institute (API) 21.1 standard. This overview is for those who are new to the industry or for those who are looking for a refresher on the basic application of flow computers. As natural gas moves from the well head to the burner tip, there are several electronic devices in the field used for measurement and control. The electronic flow computer is referred to in API 21.1 as a tertiary device in the electronic gas measurement system (EGM). In the natural gas industry a flow computer is used for differential meter measurement or used for linear meter measurement. Many contracts between companies for custody transfer of natural gas often stipulate that measurement falls into compliance of API 21.1.
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Document ID: CCBD1E60

FUNDAMENTALS OF GAS TURBINE METERS
Author(s): PAUL HONCHAR
Abstract/Introduction:
The majority of all gas measurement used in the world today is performed by two basic types of meters, positive displacement and inferential. Positive displacement meters, consisting mainly of diaphragm and rotary style devices, generally account for lower volume measurement. Orifice, ultrasonic and turbine meters are the three main inferential class meters used for large volume measurement today. Turbines are typically considered to be a repeatable device used for accurate measurement over large and varying pressures and flow rates. They are found in a wide array of elevated pressure applications ranging from atmospheric conditions to 1440 psig. Turbine meters have also become established as master or reference meters used in secondary calibration systems such as transfer provers. A significant number of both mechanical and electrical outputs and configurations have become available over the past 60 years of production. This paper will focus on the basic theory, operating principles, performance characteristics and installation requirements used in turbine meter applications. A discussion of fundamental turbine meter terminology is also included.
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Document ID: 4D911C06

DISTRIBUTION GAS METER PROVING: THE EQUIPMENT AND METHODOLOGY USED TODAY IN THE NATURAL GAS INDUSTRY
Author(s): GREGORY A. GERM
Abstract/Introduction:
To determine the accuracy of a natural gas meter, a known volume of air is passed through the meter, and the meter registration is compared against this known volume. The known volume of air originates from the meter prover. In earlier times, the gas meter prover was a stand-alone device (usually a bell-type prover), manually operated without any electronics or automation. Today, the majority of gas meter provers are fully automated computer controlled and operated, and responsible for other job functions besides the proving of gas meters. The bell-type meter prover - though still commonly used in the industry - is not the only kind of meter prover used today. The advancements and developments in electronics and computer technology has lead to an evolution of meter proving equipment - far from the manual proving methods that were commonplace only a few decades ago. Many utilities have replaced the bell-type prover with sonic nozzle and transfer provers. Provers can now store and retrieve information from a utilitys meter management system, reduce the human error factor in the proving operation, and provide self-diagnostics to assist the prover operator in maintenance and in troubleshooting problems.
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Document ID: E352F737

HYDROCARBON DEW POINT MEASUREMENT IN NATURAL GAS
Author(s): ANDY BENTON
Abstract/Introduction:
Hydrocarbon dew point (HCDP) in natural gas is an important quality parameter, stipulated in tariff specifications and enforced throughout the supply chain, from producers through transmission and distribution companies to final end-users. Accurately monitoring hydrocarbon dew point temperature in natural gas is vital if the integrity of pipeline infrastructure and quality of the gas are to be maintained, in compliance with contractual agreements.
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Document ID: ED77FD29

INSTALLATION OF GAS ULTRASONIC FLOW METERS
Author(s): DAVID CRANDALL
Abstract/Introduction:
Ultrasonic meters measure with exceptional precision when they are installed according to the manufacturers and the AGA recommendations. Keeping this in mind, the success or failure of an ultrasonic meter installation for custody transfer applications heavily depends on how it is installed. The challenges to successful installations arise when shortcuts are taken to lower costs or to meet specific site related issues. It is normally when these shortcuts are employed that one finds the meters installed performance varies from the meters calibrated performance. In custody transfer using liquid ultrasonic metering installations a field standard called a prover is used to compare its known volume to the volume measured by the meter. A correction factor, referred to as the meter factor, is applied to the volumetric calculations as an adjustment to the meters measurements. Gas ultrasonic metering installations typically do not have this standard known volume in the form of a prover and as a result, the gas industry depends upon transferring the meters laboratory calibrations directly to the field. This makes it imperative that the installation replicate as closely as possible the calibration conditions. This paper outlines the methods of installation that are known to deliver optimum performance. There are also references to AGA Report #9 2017 dealing with installation guidelines.
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Document ID: 0C4638D2

INTRODUCTION TO GAS REGULATORS
Author(s): ROBBIE SWIGERT
Abstract/Introduction:
A gas regulator is a device designed to reduce inlet pressure, which may vary, to a constant lower outlet pressure. It controls the flow of gas to meet downstream demand. The regulator will shut off bubble tight between the inlet pressure side and the outlet pressure side when there is no downstream demand. Safeguards against downstream over pressurization, such as an internal relief valve or internal monitor orifice, are built into many regulators. The ideal regulator would reduce widely varying inlet pressure to a perfectly constant outlet pressure. It would do this from zero flow to the maximum flow capacity of the regulator.
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Document ID: 97DB8B41

Introduction to Over Pressure Protection
Author(s): PETER CATHCART
Abstract/Introduction:
This paper serves as a high-level summary of equipment-based methods available to prevent over-pressuring of downstream gas piping. This topic will primarily be represented in relation to United States Department of Transportation requirements in 49 CFR Part 192 with recognition that the Canadas governing regulations CSA Z662 may vary on specific requirements. Recommendations for design and use are included, but are not considered to be an authority on design requirements or industry best practice.
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Document ID: 8B0A4412

INTRODUCTION TO GAS METERING
Author(s): ROBERT BENNETT
Abstract/Introduction:
Science interprets nature in terms of matter and energy. Energy is defined as the capacity to do work. There are many types of energy such as heat energy, electrical energy, chemical energy, kinetic energy (energy of motion), and potential energy (intrinsic energy of an object due to the position of the object). Matter is the material of which the universe is composed and is defined as anything that occupies space and has mass. There are three normal states of matter - solid, liquid, and gas. Under certain conditions, most substances can be made to exist in any of the three states, i.e. water as steam, liquid, or ice. Solid matter is rigid, generally crystalline, and will exhibit a definite shape. Liquids will flow, assume the shape of the container they are stored, and considered to maintain a constant volume and density. Gaseous matter is much more difficult to qualify since it consists of widely separated molecules in rapid motion. The comparatively large distances between the molecules make it possible for one gas to accommodate molecules of another gas or be compressed to force the individual molecules closer together. Since the molecules are in constant motion, they will expand to fill any container and strike the walls of the vessel. These myriad impacts result in a pressure.
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Document ID: 2E691F36

INTRODUCTION TO GAS QUALITY
Author(s): MAY LEW
Abstract/Introduction:
When you think of natural gas measurement you most likely think of meters or volume measurement. However, gas bills are in therms not flow rates like scf or Mcf. To determine therms we need to know the flow rates and billing rates (BTU). BTU is determined by measurements of other parameters like hydrocarbon composition, carbon dioxide, and nitrogen. But is that all that needs to be measured by a gas distribution company? In order to transport gas through pipelines and supply customers, other measurement devices may be needed to ensure an acceptable gas quality. Acceptable gas quality is specified in Tariffs or in contractual agreement between the utility and its gas suppliers. In this presentation we will go over typical natural gas parameters that should be specified.
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Document ID: 1F9EF0AE

INTRODUCTION TO GAS ULTRASONIC METERS
Author(s): JOHN LANSING
Abstract/Introduction:
This paper is an overview gas ultrasonic meters, which are also known as USMs. Discussion topics include principles of operation, different path configurations, basic diagnostic features, AGA Report No. 9, flow calibration issues, flow conditioning, basic piping design, routine maintenance considerations, control valve noise mitigation and a variety of other aspects to consider when using gas ultrasonic meters (USMs). It primarily discusses fiscal-quality, multi-path USMs and does not cover issues that may be different with non-fiscal meters. These are typically single path designs which can be spool-piece meters or clamp-on designs. Although todays USMs use the same transit-time principle of operation, diagnostics for each manufacturer does vary. This will be discussed in some detail later in this document. Additionally, all brands and path configurations that are used for custody transfer applications must meet basic requirements as discussed in The American Gas Associations AGA Report No. 9 Ref 1 & 2.
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Document ID: FF71A37A

INTRODUCTION TO REGULATOR AND RELIEF VALVE SIZING
Author(s): MARK DYKOFF
Abstract/Introduction:
Regulators used in natural gas applications are devices made up of a valve and actuator, in combination, that use the motive force generated by an imbalance between the process pressure and a loading element to throttle a valve, maintaining the process pressure at a set value under varying demand. Throughout this paper the term regulator will be used for any device that is sensing and controlling a downstream pressure (P2) and a relief valve is any device sensing an upstream pressure (P1), particularly with the intent of providing overpressure protection. Both devices operate under the same principles however the application of each device is unique. Well start with an introduction to the principles of operation and sizing of regulators and the discussion of relief valves will follow.
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Document ID: 563440BC

DECOMMISSIONING OF NATURAL GAS ODORIZATION EQUIPMENT
Author(s): WESLEY LUCAS
Abstract/Introduction:
The natural gas industry is a fast-growing segment of our energy industry and there is a need to keep operations safe and environmentally friendly. Obsolete odorization equipment needs to be removed and disposed of in an environmentally sounds and odor-free manner in order to avoid business disruption or potential liquid/vapor odorant leaks from obsolete equipment. This article will go through some of the drivers for decommissioning of odorizer equipment, the process of decommissioning of odorizer equipment, health and safety concerns revolving around decommissioning of odorizer equipment and environmental hazards to be considered when decommissioning odorization equipment.
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Document ID: 9BEF50B6

METER SAMPLING THEORY
Author(s): DAVID THAI
Abstract/Introduction:
Many utilities have developed programs for meter operation, maintenance, and replacement. There are no comprehensive studies to date that define the exact age or amount of throughput when meter accuracy is degraded to a point that replacing it becomes economically beneficial. Accounting for meter accuracy in a distribution system is mandated for most utilities and one of the most difficult to manage without a meter test program. Elements of the meter test program require investigating the relationship between meter accuracy degradation and other factors (i.e. age, wear, workmanship and throughput for in- service meters).
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Document ID: B00D6260

Monitor Strategies And Implementation
Author(s): Claude Transue & Jim Green
Abstract/Introduction:
There are three basic methods of providing overpressure protection in a gas pipeline system Pressure Relief Valve, Pressure Limiting (Monitor) Regulators, and Automatic Shutoff Valves. Of these three methods, one vents overpressure to atmosphere and the other two will capture and control overpressure in the pipeline. In this paper, we will cover the two methods that capture and control overpressure conditions in the pipeline Pressure Limiting Monitors and Automatic Shutoff Valves (Slam Shut Devices). In years gone by, the most common overpressure protection method in pipelines was a Primary Regulator with a downstream Pressure Relief Valve that vented to atmosphere. A simple proven method of Overpressure Protection to be sure, but this form of overpressure protection is not as dominant as it once was in the Natural Gas Industry. The primary form of overpressure protection today is the Pressure Limiting Monitor Regulator. This Monitor Regulator acts as a second pressure controlling device, in series with the Primary Regulator, to provide overpressure protection and containment in the event of a Primary failure. A second form of overpressure protection and containment is an Automatic Shutoff Valve also known as a Slam Shut Device. Both strategies sense the same downstream pressure as the Primary Regulator and provide overpressure protection. When a Monitor regulator performs this job, it Monitors the primary regulator and, and thus gets its name from this responsibility. When an Automated Shutoff valve performs this job, it Slams Shut the pipeline on an overpressure condition, and thus gets its name from this responsibility. The difference between the two is the Monitor regulator will take over and control the pipeline at a slightly higher pressure than the Primary Regulator and thus keeps the pipeline flowing. The Slam Shut device will shut down the pipeline in the event of an overpressure condition.
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Document ID: D807C857

NOISE MITIGATION IN REGULATOR STATIONS
Author(s): LAMAR MAY
Abstract/Introduction:
A common attribute of many regulator stations is a high level of noise. In many cases this is the single largest complaint the surrounding community has with the presence of the regulator station. However, many times this noise is unnecessary and can be significantly reduced, particularly if the issue is caught at the design stage. In order to manage station noise, we first need to understand what it is and where it comes from.
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Document ID: 9CF81B2D

Odorant Transfer and Delivery Systems
Author(s): JURAJ STRMEN
Abstract/Introduction:
Natural gas odorant, often referred to as mercaptan odorant, is a liquid that is added to natural gas to impart a distinct sulfur smell to the gas that is otherwise odorless. There are about a dozen different blends of natural gas odorants used in the US. Most of them are based on two main components: the odorant and the antifreeze agent. The odorant portion can be either mercaptan- or thiophane-based. The antifreeze agent is typically isopropyl mercaptan or a sulfide such as dimethyl sulfide. In the US, odorant liquids are manufactured in refineries and transported by truck or DOT tanks to client sites. At the client site, transport tanks are offloaded to bulk odorant storage tanks. Typical refill frequency for bulk odorant storage tanks is once per year.
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Document ID: 0B47FBA5

Operation and Maintenance Online Gas Chromatographs
Author(s): Jamie Marsden
Abstract/Introduction:
The gas chromatograph (GC) is an integral component of the natural gas custody metering station and has a significant impact on the accuracy of the fiscal flow calculation. For this reason, it is imperative that you install, operate and maintain the GC with the goal of maximum reliability and accuracy.
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Document ID: 1AE075C6

PRINCIPLES OF ODORIZATION AND ODORANT PRODUCT STEWARDSHIP
Author(s): OLIVIER GRIPERAY
Abstract/Introduction:
Natural gas has become one of the most preferred sources of energy for people around the world. It is more and more abundant, one of the cleanest fossil energies available, and with proper protocols, can be made relatively safe for use. The importance of focusing on safety was brought to the forefront by the 1937 New London, Texas tragedy in which hundreds of lives were lost in an explosion at a school caused by an undetected gas leak. At the time, natural gas was not odorized, and natural gas leaks were undetectable by the general public. Lawmakers around the world quickly realized that their constituents, and their own families, were exposed to a growing danger. As the use of clean natural gas expanded, something had to be done to alert people before the concentration of natural gas in air became explosive. Chemists found a simple way to solve this issue. When gas was made from coal, it had a distinctive sulfuric odor, but pure natural gas is odorless. By adding back that distinctive odor to the gas, people could easily detect the odor and the possibility of a gas leak. The odorization of natural gas created a system that warns people before the concentration of gas in the air becomes dangerous.
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Document ID: BD81F168

REGULATOR FREEZE PROCTECTION
Author(s): AUSTIN SORENSEN
Abstract/Introduction:
Freezing can be a problem in both transmission and distribution systems in the natural gas industry. This problem can affect a Companys ability to deliver gas on demand. Damaging its reputation and its license to operate in the publics eye. It typically occurs when there is a reduction of pressure at natural gas regulating stations. The problem can be complex so there are multiple solutions to address the problem. The four primary contributors to the problem are pressure drop, presence of water, hydrocarbon liquids, and ambient temperature. Hydrocarbon dew points also need to be considered when dealing with hydrate issues. The Joule-Thompson (JT) effect is what causes the hydrate to form with pressure drop. As the pressure of a gas drops, so does the temperature. For every 100 psi of pressure drop, the temperature of natural gas will drop approximately 7 degrees F as a good rule of thumb.
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Document ID: 0F193A14

Regulator In-Testing - Quality Management and Reporting
Author(s): Peter Klock
Abstract/Introduction:
The topic for this short course is Regulator In- Testing and QA Reporting. Before we get into the details, it is interesting to note that not all LDC utilities agree that the meter shop needs to in-test natural gas pressure regulators. While this is up to the individual utility management, there is a definite movement to actively verify that the product provided by the manufacturer meets the specific requirements expected by the procurement specification. The way to do this is to Expect (QA) and Verify (QC) which is the essence of quality management. Bottom line is that operations that employ the best practices of QA/QC provide a measurable difference in the quality of the product. This is proven to be the case for spring-loaded pressure regulators. The meter shop plays an important role. The fact is that the regulator manufacturers make quality products but when they know that the utility buyer in-tests to verify that the product meets specific procurement specifications they are more careful.
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Document ID: EF526DFC

DIFFERENTIAL TESTING of ROTARY METERS
Author(s): MADELINE CORB
Abstract/Introduction:
A Differential Rate Test is an accurate and convenient method of comparing a rotary meters performance to previous or original performance records. It is widely recognized that many State Utility Commissions and other regulatory agencies accept differential testing as a means of periodically substantiating that the original accuracy of a rotary gas meter has remained unchanged. A change in internal resistance can affect the accuracy of a rotary meter. Any significant increase on the meters internal resistance to flow will increase the pressure drop between the inlet and outlet of the meter. The differential pressure appears as a prime indicator of meter condition and the test results may be used as a decision- making matrix for maintenance requirements. Resistance (increase in pressure loss) across the meter is affected by changes in flow rate, pressure, specific gravity, and internal friction. This is a good indicator to use in determining your need to pull a meter from service, or better yet a preventive maintenance program. Most meters can be flushed with an approved safety solvent, returned to service, and the differential will be close to the original data. If it exceeds specified criteria, normally a 50% increase from the baseline, the meter may require repair. The differential rate test is not an accuracy test. It does provide an excellent basis for assessing meter condition and making an educated decision as to whether the meter accuracy may be out of the users accuracy specifications.
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Document ID: 1ED21540

TROUBLESHOOTING REGULATORS: CAUSES AND CURES OF REGULATOR INSTABILITY
Author(s): PAUL R. ANDERSON
Abstract/Introduction:
This paper will address the gas pressure reducing regulator installation and the issue of erratic control of the downstream pressure. A gas pressure reducing regulators job is to manipulate flow in order to control pressure. When the downstream pressure is not properly controlled, the term unstable control is applied. Figure 1 is a list of other terms used for various forms of downstream pressure instability. This paper will not address the mathematical methods of describing the automatic control system of the pressure reducing station, but will deal with more of the components and their effect on the system stability.
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Document ID: B191C21D

ULTRASONIC METER DIAGNOSTICS
Author(s): Joel Nava
Abstract/Introduction:
Ultrasonic meters are now, and have been for some time, the measurement technology of choice for pipeline custody transfer applications. This technology is also appearing more and more in the upstream and the distribution market segments as well as a measurement solution. It is not hard to imagine that every molecule of gas consumed in the US has passed through an ultrasonic gas meter at some point in time along its journey. It is important for individuals in the measurement industry to understand this technology and the advantages ultrasonic meters have to offer. Ultrasonic meters offer a host of diagnostics that are unmatched by other technologies. This paper will review the basic technology used in multipath chordal ultrasonic meters commonly found in custody transfer applications. It will also discuss some of the diagnostic information they can provide and how this information may be interpreted to provide an indication of the meter and of the meter runs health.
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Document ID: B97269C3

Natural Gas Measurement Standards Update
Author(s): Terrence A. Grimley, Ardis Bartle
Abstract/Introduction:
[Abstract Not Available]
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Document ID: B73D72C8

Three Mode Controller (PID) Tuning
Author(s): Ed AUSTIN
Abstract/Introduction:
A PID Controller is a proportional-integral- derivative controller. It has been relatively unchanged since its inception in 1939. In some applications, maybe only Proportional control is needed. In other applications, PI (Proportional and Integral), are best used. Still in other applications, all three modes, PID, is your best performing loop control. You may not even know it but youve been exposed to various PID Controllers throughout your life ranging from a thermostat in your home for controlling temperature to the cruise control on a vehicle. There are numerous examples in refineries, chemical processing plants, paper mills, power plants and on and on. To fully understand and truly learn PID control would take weeks of class, lab time, and field training. This paper is not intended to make you experts in tuning but rather, provide you with the fundamentals and basic understanding that you can use as a building block in preparation for when the opportunity presents itself in the field.
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Document ID: 00E0F9A7

ATMOSPHERIC CORROSION MITIGATION FOR EXPOSED STEEL STATION PIPING
Author(s): KELLY CRYSTAL
Abstract/Introduction:
Why is it important to prevent corrosion? It causes deterioration of the steel pipe and if not controlled can lead to unsafe conditions of the pipeline. Our number one priority as pipeline operators is to put public safety first, so taking steps to protect our pipeline is of the utmost importance. Atmospheric corrosion mitigation for exposed steel station piping seems to be a battle that many of us in the gas industry deal with every day. This paper will give some insight on what causes corrosion, understanding corrosion, and the atmosphere involved in the corrosion cell. We will also discuss what steps can be taken to help mitigate corrosion on exposed station piping. This is intended to be a basic understanding for the gas measurement personnel, to be better prepared for inspection and maintenance of the facility. It is important to remember that all federal and state rules and regulations and all company policies and procedures must be followed. Some of the information in this paper is my suggestion or recommendation based off my personal experiences. Remember, when it comes to atmospheric corrosion mitigation of exposed steel piping, there could be more than one remedy.
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Document ID: F0C2E774

PREVENTATIVE VS. REACTIVE VALVE MAINTENANCE
Author(s): JASON DELLOW
Abstract/Introduction:
Preventative and reactive valve maintenance plays a key role in the safe and legal operations of natural gas distribution and transmission systems. Despite the requirements of federal regulatory agencies, routine valve maintenance is often an important part of the business that becomes neglected. Reactive valve maintenance can often be defined as the maintenance performed when the reliability or usefulness of system valves have depreciated or failed. On the other hand, preventative valve maintenance suggests that we as pipeline operators take a proactive approach in mitigating valve issues before they occur. Despite the challenges in designing and executing a successful valve maintenance program, building a safe and reliable valve network is of the utmost importance. This paper will discuss the importance of a preventative valve maintenance agenda and will study ways to easily alleviate the risks of putting the operators in a vulnerable position due to a valve failure.
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Document ID: 0D350AC7

PRACTICAL SELECTION AND USAGE OF CORIOLIS METERS FOR GAS MEASUREMENT
Author(s): TONYA WYATT
Abstract/Introduction:
Coriolis meters have been commercially produced and gaining in popularity since the late 1970s. While Coriolis meters were more commonly used for liquid applications initially, they measure liquids, slurries and gases very precisely. Use of Coriolis meters for gas applications has become increasingly popular since 2003 when American Gas Association (AGA) Report No. 11/American Petroleum Institute Manual of Petroleum Measurement (API MPMS) Standards Chapter 14.9, Measurement of Natural Gas by Coriolis Meter was published. The second edition of AGA Report No. 11/API MPMS Chapter 14.9 was published in 2013 and expanded the guidelines for the use of Coriolis meters for natural gas measurement.
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Document ID: 02339F64

Impact of Temperature, Pressure, and Other Factors on Metering Accuracy
Author(s): Paul W. Tang
Abstract/Introduction:
This paper presents an overview of the impact of temperature, pressure, and other factors on natural gas metering accuracy. Metering accuracy is a vast topic. Although some of the general measurement principles described here are applicable to most gas metering installations, the focus of this paper is on high volume devices such as turbine, ultrasonic, and Coriolis meters.
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Document ID: E9224243

Field Verification of Ultrasonic Gas Meter Stations
Author(s): Jeremy Fernandez, Geoff Hager, Thomas Kegel
Abstract/Introduction:
Many tools are available to assure consistent measurement gas measurement. Ultrasonic meters offer several diagnostic parameters, some designs include extra acoustic paths. Meter stations are being designed with integral check meters. A remote monitoring service1 brings a higher level of experience to the evaluation of diagnostic and check meter data. This paper discusses a new service based on bringing an independent check meter to a meter location.
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Document ID: EA5752B2

WAR STORIES : Solving Complex Process Analyzer Problems in the Field Working on Gas Chromatographs & Tape Systems
Author(s): Erik Budlong
Abstract/Introduction:
Process analyzers are instruments used to continuously monitor gas or liquid streams. Instead of periodically manually taking a grab sample for testing in the lab, the analyzer provides real-time data that can be transmitted to a data acquisition system (DCS). This non-stop measurement sequence helps optimize process control and instantly detects unexpected upsets. In addition to improving product quality and safety, operators can also ensure environmental compliance. The oil and gas industry employs a wide range of process analyzers throughout the value chain from upstream drilling to downstream distribution. Analyzers utilize specific technologies required to perform the measurement (eg. H 2 S) of interest. Operators face the challenge of becoming knowledgeable with how each of these technologies work. This knowledge is critical for keeping their analyzers online and working properly. If this wasnt difficult enough, plants and pipelines often have the same type (eg. gas chromatograph) of analyzer purchased from several manufacturers. Each manufacturers analyzer follows the same theory of operation, but can vary in components and user interface. On top of that, operators are frequently reassigned to a new station, which means they have very little time to get caught up to speed on a new analyzer. They just hope nothing bad happens under their watch.
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Document ID: A37CCA8E

METER SET DESIGN
Author(s): Eric Kaert
Abstract/Introduction:
Having to build one meter set isnt that large of an under taking. There are lots of different ways it could be built and it could be pieced together in the field. When having to build thousands however, like gas utilities do, every factors impact is multiplied many times over. It is the volume, that they are installed everywhere in communities and that they are the final component in the distribution system that makes meter set design so important. All meter sets must be safe and reliable while also being cost effective so different applications require different approaches. The requirements for a small residential service are different than a large industrial customer and we will review potential configurations to accommodate this. This paper will cover a variety of aspects pertaining to above ground distribution meter set assemblies. It will look at the components involved, different forms of overpressure protection, layouts, different approaches for construction and implementation, as well as some of the differences between residential, commercial and industrial services. Is it acceptable to shutoff gas in an overpressure event using a slamshut, is a single run sufficient or should a main and alternate run be used? A variety of components and approaches will be reviewed to show there may not be one correct answer but rather choices for gas utilities to choose from based on how they want their system to function.
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Document ID: 40CB1C3E

Distribution System Pressure Monitoring
Author(s): JOHN SWARTZ, TUSHAR SHAH
Abstract/Introduction:
The natural gas industry operates an extensive system of 2.4 million miles of distribution and transmission pipelines across the country to supply natural gas to more than 117 million customers. The design, construction, operation, inspection and maintenance of all operating pipelines are subjected to state and federal regulations. The Pipeline and Hazardous Material Safety Administration (PHMSA) is the primary Federal Administration responsible for ensuring that the pipelines are safe, reliable, and environmentally sound. The Code of Federal Regulations (CFR) 49, Parts 190-199 includes the rules to govern pipeline safety. Individual states may have additional pipeline safety regulations. In particular, Part 192 prescribes a wide variety of minimum safety requirements for gas pipelines. This regulation contains sections applicable to gas gathering, transmission and distribution.
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Document ID: AE38BC65

HAZARDOUS AREA CLASSIFICATION
Author(s): ALEX HICKS & HILLARY MATORA
Abstract/Introduction:
Hazardous (classified) areas are defined and categorized by the National Fire Protection Association (NFPA) 70, the National Electric Code (NEC). In particular, Articles 500, 501, 504, and 505 cover hazardous areas that are created by common gas utility processes. Although the NEC provides a general definition of hazardous areas and the installation requirements of electrical equipment located within them, it does not classify specific natural gas and petroleum industry processes that can create a hazardous area, nor the extent of the hazardous areas created by such processes. Instead NFPA technical committees and the American Petroleum Institute (API), among other industry-recognized organizations, determine the specifics of hazardous areas created by gas and petroleum industry processes. Two particular publications have become the de facto standards for defining hazardous areas in the natural gas and petroleum industry: the API 500 and the American Gas Associations (AGA) XL1001.
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Document ID: 5A4EC1C6

TELEMETRY AND WIRELESS COMMUNICATIONS AT STATIONS CONSIDERATIONS FOR TELEMETRY
Author(s): Mike Pugh
Abstract/Introduction:
Supervisory Control and Data Acquisition (SCADA) is a system architecture that employs computers, communications equipment, and peripheral devices to interface the outside world with the digital world. Often, the word telemetry is used in place of SCADA. Telemetry is a broad term defined as any device for recording or measuring a distant event and transmitting the data to a receiver or observer. As such, a person could be used as telemetry. For the purposes of this presentation, the term SCADA will be used.
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Document ID: 57AC8319

TROUBLESHOOTING CONTROL VALVES: A SYSTEMATIC PROBLEM SOLVING APPROACH
Author(s): JIM GREEN
Abstract/Introduction:
Troubleshooting Control Valves is a very broad subject to cover given the vast array of Valves, Actuators, and Control Instrumentation available in the market today. We have Ball Valves, Globe Valves, Plug Valves, Butterfly Valves, and Segmented Ball Valves just to name a few. All of these Control Valves can be outfitted with various types of Valve Trim, Actuators, and Control Instrumentation to characterize and fine-tune the performance of the valve to achieve a desired control effect. The possible problems that can arise can be as simple as an external leak to a total loss of Process Control. Technicians are tasked to fix mechanical, electronic, and pneumatic issues as well as be qualified to perform complex tuning of the Control Valve System to achieve solid Process Control under many varying conditions. With all these variations, the job of the Control Valve Technician is a challenging one that requires a person to be adept in Mechanics, Pneumatics, Instrumentation, and Electronics. Even if a Technician is qualified in all of these areas, their success in troubleshooting control valves requires them to be knowledgeable in two critical areas:
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Document ID: B55E1842


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