Showing posts with label Arkansas. Show all posts
Showing posts with label Arkansas. Show all posts

Tuesday, January 30, 2018

Steam Boiler Water Level Control

Steam boiler level control diagram.
Steam boiler level control diagram.
Click on image for larger view.
Steam boilers are very common in industry, principally because steam power is so useful. Common uses for steam in industry include doing mechanical work (e.g. a steam engine moving some sort of machine), heating, producing vacuums (through the use of “steam ejectors”), and augmenting chemical processes (e.g. reforming of natural gas into hydrogen and carbon dioxide).

The process of converting water into steam is quite simple: heat up the water until it boils. Anyone who has ever boiled a pot of water for cooking knows how this process works. Making steam continuously, however, is a little more complicated. An important variable to measure and control in a continuous boiler is the level of water in the “steam drum” (the upper vessel in a water-tube boiler). In order to safely and efficiently produce a continuous flow of steam, we must ensure the steam drum never runs too low on water, or too high. If there is not enough water in the drum, the water tubes may run dry and burn through from the heat of the fire. If there is too much water in the drum, liquid water may be carried along with the flow of steam, causing problems downstream.

The first instrument in this control system is the level transmitter, or “LT”. The purpose of this device is to sense the water level in the steam drum and report (“transmit”) that measurement to the controller in the form of a signal. In this case, the type of signal is pneumatic: a variable air pressure sent through metal or plastic tubes. The greater the water level in the drum, the more air pressure output by the level transmitter. Since the transmitter is pneumatic, it must be supplied with a source of clean, compressed air on which to operate. This is the meaning of the “A.S.” tube (Air Supply) entering the top of the transmitter.

This pneumatic signal is sent to the next instrument in the control system, the level indicating controller, or “LIC”. The purpose of this instrument is to compare the level transmitter’s signal against a setpoint value entered by a human operator representing the desired water level in the steam drum. The controller then generates an output signal telling the control valve to either introduce more or less water into the boiler to maintain the steam drum water level at setpoint. As with the transmitter, the controller in this system is pneumatic, operating entirely on compressed air. This means the output of the controller is also a variable air pressure signal, just like the signal output by the level transmitter. Naturally, the controller requires a constant supply of clean, compressed air on which to run, which explains the “A.S.” (Air Supply) tube connecting to it.

The last instrument in this control system is the control valve, operated directly by the air pressure signal output by the controller. Its purpose is to influence the flow rate of water into the boiler, “throttling” the water flow more or less as determined by controller. This particular type of control valve uses a large diaphragm and a large spring to move the valve further open with more signal pressure and further closed with less signal pressure.

When the controller is placed in the “automatic” mode, it will move the control valve to whatever position necessary to maintain a constant steam drum water level. The phrase “whatever position necessary” suggests the relationship between the controller output signal, the process variable signal (PV), and the setpoint (SP) is complex. If the controller senses a water level above setpoint, it will close off the valve as far as necessary to decrease the water level down to setpoint. Conversely, if the controller senses a water level below setpoint, it will open up the valve as far as necessary to raise the water level up to setpoint.

What this means in a practical sense is that the controller’s output signal (equating to valve position) in automatic mode is just as much a function of process load (i.e. how much steam is being used from the boiler) as it is a function of setpoint (i.e. where we wish the water level to be). Consider a situation where the steam demand from the boiler is very low. If there isn’t much steam being drawn off the boiler, this means there will be little water boiled into steam and therefore little need for additional feedwater to be pumped into the boiler. Therefore, in this situation, one would expect the control valve to hover near the fully-closed position, allowing just enough water into the boiler to keep the steam drum water level at setpoint. If, however, there is a high demand for steam from this boiler, the rate of evaporation will be much greater. This means the control system must add feedwater to the boiler at a much greater flow rate in order to maintain the steam drum water level at setpoint. In this situation we would expect to see the control valve much closer to being fully-open as the control system “works harder” to maintain a constant water level in the steam drum. Thus, we see how the controller automatically positions the control valve to react to different boiler operating conditions even when the setpoint is fixed.

A human operator supervising this boiler has the option of placing the controller into “manual” mode. In this mode the control valve position is under direct control of the human operator, with the controller essentially ignoring the signal sent from the water level transmitter. Being an indicating controller, the controller faceplate will still show how much water is in the steam drum, but it is now the human operator’s sole responsibility to move the control valve to the appropriate position to hold water level at setpoint – in manual mode the controller takes no corrective action of its own. Manual mode is useful to human operators during start-up and shut-down conditions. It is also useful to instrument technicians for troubleshooting misbehaving control systems. Placing a controller into manual mode is akin to disengaging the cruise control in an automobile, transferring control of engine power from the car’s computer back to the human driver. One can easily imagine an automobile mechanic needing to throttle a car’s engine “manually” (i.e. with the cruise control turned off) in order to properly diagnose an engine or drivetrain problem. This is true for industrial processes as well, where instrument technicians may need to place a controller into manual mode in order to properly diagnose transmitter or control valve problems.

Reprinted from Lessons In Industrial Instrumentation by Tony R. Kuphaldt – under the terms and conditions of the Creative Commons Attribution 4.0 International Public License.

Wednesday, January 24, 2018

Two Point Calibration of the Foxboro IDP-10-T Pressure Transmitter

The Foxboro / Schneider Electric I/A Series Electronic Pressure Transmitters are a complete family of D/P Cell, gauge, absolute, multirange, multivariable, and premium performance transmitters, as well as transmitters with remote or direct connect seals, all using field-proven silicon strain gauge sensors and common topworks.

A common HART electronics module is used for all HART Pressure Transmitters. Also, because all configuration and calibration data is stored in the sensor, you can replace a HART module with another HART module without transmitter reconfiguration or recalibration.

The video below provides step-by-step instructions for two point calibration of the IDP-10-T pressure transmitter.

Tuesday, January 16, 2018

Flowserve Limitorque WG Series Gear Operator Installation, Maintenance, and Operation Guide

WG Series Gear Operator
WG Series Gear Operator (Limitorque)
The most basic function of a valve is to be opened and closed, allowing or preventing a process media to flow. Gearboxes, such as the WG series, provide the mechanical advantage to make hand operation possible for most valves.

The Flowserve Limitorque WG series of worm gearboxes is designed for quarter-turn butterfly, ball, and plug valve applications as well as quarter-turn and multi-turn dampers and offers unsurpassed quality and longevity in a wide variety of weatherproof, submersible and buried-service applications.

The following installation and maintenance manual (IOM) explains how to install and maintain the Flowserve Limitorque WG operator. Information on installation, disassembly, reassembly, lubrication and spare parts is provided in the embedded document below.

Alternatively, you can conveniently download the Limitorque WG Series Installation, Operation, and Maintenance in PDF here.

Friday, December 29, 2017

Process Temperature Sensors: Basics of Thermocouples and RTDs

Industrial Thermocouple
Industrial Thermocouple
(Ashcroft)
Proper temperature sensor selection is key to getting useful and accurate data for maintaining control of a process. There are two main types of temperature sensors employed for industrial applications, thermocouple and resistance temperature detector (RTD). Each has its own set of features that might make it an advantageous choice for a particular application.

Thermocouples consist of a junction formed with dissimilar metal conductors. The contact point of the conductors generates a small voltage that is related to the temperature of the junction. There are a number of metals used for the conductors, with different combinations used to produce an array of temperature ranges and accuracy. A defining characteristic of thermocouples is the need to use extension wire of the same type as the junction wires, in order to assure proper function and accuracy.

Here are some generalized thermocouple characteristics.
  • Various conductor combinations can provide a wide range of operable temperatures (-200°C to +2300°C).
  • Sensor accuracy can deteriorate over time.
  • Sensors are comparatively less expensive than RTD.
  • Stability of sensor output is not as good as RTD.
  • Sensor response is fast due to low mass.
  • Assemblies are generally rugged and not prone to damage from vibration and moderate mechanical shock.
  • Sensor tip is the measuring point.
  • Reference junction is required for correct measurement.
  • No external power is required.
  • Matching extension wire is needed.
  • Sensor design allows for small diameter assemblies. 
RTD sensors are comprised of very fine wire from a range of specialty types, coiled within a protective probe. Temperature measurement is accomplished by measuring the resistance in the coil. The resistance will correspond to a known temperature. 

Industrial RTD
Industrial RTD
(Ashcroft)
Some generalized RTD attributes:
  • Sensor provides good measurement accuracy, superior to thermocouple.
  • Operating temperature range (-200° to +850°C) is less than that of thermocouple.
  • Sensor exhibits long term stability.
  • Response to process change can be slow.
  • Excitation current source is required for operation.
  • Copper extension wire can be used to connect sensor to instruments.
  • Sensors can exhibit a degree of self-heating error.
  • Resistance coil makes assemblies less rugged than thermocouples.
  • Cost is comparatively higher.
Each industrial process control application will present its own set of challenges regarding vibration, temperature range, required response time, accuracy, and more. Share your process temperature measurement requirements and challenges with a process control instrumentation specialist, combining your process knowledge with their product application expertise to develop the most effective solution.

Sunday, December 24, 2017

Metso Neles T5 Series Top Entry Rotary Ball Valves

Metso's Neles T5
Metso's Neles® T5 series top entry rotary ball valves are designed to meet the requirements of chemical, petro-chemical and refining industries with improved process safety and efficiency of plant.

T5 series valves with famous trunnion mounted Stemball® design are suitable with wide rangeability for demanding heavy duty rotary control applications such as crude oil, hot residual oil, LPG and other hydrocarbon gases and vapors under medium and high pressures. 

Unique Stemball® design combined with anti-cavitation and low noise Q-trim technology are making the T5 series valve most suitable with wide rangeability for demanding control applications like anti surge and blow down services. The new high noise reduction Q2-trim is available for gas applications.

Sunday, December 17, 2017

Process Control Basics: The Underlying Principle Behind Coriolis Flowmeters

The Coriolis effect, a derivative of Newtonian motion mechanics, describes the force resulting from the acceleration of a mass moving to (or from) the center of rotation. As this video demonstrates, the flowing water in a loop of flexible hose that is “swung” back and forth in front of the body with both hands. Because the water is flowing toward and away from the hands, opposite forces are generated and cause the hose to twist. Coriolis flowmeters apply this principle to measure fluid flow.


For more information on any process flow application, contact Mead O'Brien by calling
(800) 892-2769
or by visiting https://www.meadobrien.com.

Tuesday, November 28, 2017

Pharmaceutical and Biotech Valve Communication Networks

Valve Communication Networks
Valve Communication Network
Pharmaceutical and biotech companies are facing increasing competition, driving their need for increased efficiency, reduced costs, and agility.

Automated valve systems that help reduce installation costs through easy set up, faster commissioning, and enhanced valve identification are being embraced in these industries. Features such as bright electronic indication, combined with optional remote wireless access systems, provide enhanced risk management and improved safety, which subsequently lowers overall cost.

Demands for higher product purity and productivity is pressuring Pharma and Biotech companies to make investments in new technologies that deliver improved quality and competitive agility. Process control systems, and specifically valve communication systems, are evolving to support these changes. The most significant changes to valve communications systems are:

Size

Valve communication modules that offer smaller, lighter and more durable form factors, and modules that conform to the needs of moveable process skids and flexible manufacturing provide operators are very popular in these industries. Also, the use of integral solenoid valves lessen the amount of tubing and cabling required for valve packages, affording smaller overall envelope sizes on skids.

Precision

Solid state continuous sensors increase reliability and provide precise position measurement compared to legacy mechanical or proximity-reed technology. These solid state sensors also allow for more sophisticated valve diagnostics, leading to reduced maintenance costs over the valve system's life cycle.

Predictive Maintenance

The information available for critical valve operating parameters allow operators to see potential problems early, thereby reducing the risk and potential expense from lost production and downtime. Remote valve function monitoring, which includes sensor temperature and cycle count, extends the life of critical valves and helps maintenance staff circumvent a problem before it causes a dangerous situation.

Improved Safety

Axiom
StoneL Axiom
Wireless communications and control modules allow operators to access difficult to reach valve systems safely, securely and conveniently. Critical situations are known and dealt with immediately from safe locations, and away from potentially dangerous areas or circumstances.

Remote Access and Data Collection

Typical modern valve communication networks provide tremendous advantages over traditional valve monitoring systems, namely:
  • Access devices up to 50 meters, depending on obstructions
  • Monitor on or off line and set open and closed switch positions
  • Monitor and set the network address
  • Operate solenoid valve(s) (if network- or power supply-enabled)
  • Identify model and serial number (preset from factory)
  • Identify valve automation components (entered by valve supplier)
  • Log maintenance information
  • Monitor diagnostics (valve cycle count, electronics temperature, and more)
  • Lockout of settings automatically when in operation
Solutions

Prism PI
StoneL Prism PI
Combining components such as StoneL’s Prism or Axiom platforms with a DeviceNet or AS-Interface protocol system to interconnect your automated valves will lower your construction costs and install faster than conventional systems. Additionally, using valve monitoring apps such as StoneL Wireless Link with standard iPads or iPhones provide further cost savings and security is assured. Maintenance schedules based on calendar days are no longer required - with access to cycle count data, you can perform valve maintenance when it is truly needed and replace parts prior to wearing out.
StoneL Wireless Link
Example of StoneL Wireless Link on iPhone.
To discuss any valve networking application, contact Mead O'Brien by visiting https://www.meadobrien.com or by calling (800) 892-2769.

Sunday, November 26, 2017

Understanding Vortex Shedding Flow Technology

Foxboro Vortex Shedding Flowmeter
Foxboro Vortex Shedding Flowmeter.
Notice the shedder bar in the flow path.
Photograph of vortice
Photograph of vortices
(credit Jürgen Wagner via Wikipedia)
Vortex shedding flowmeters are a type of flowmeter available to the process industry for the consistent evaluation of flow rates. These flowmeters measure the volumetric flow rate of media such as steam flowing in pipes, gases, and low viscosity liquids, boasting both versatility and dependability. Since they have no moving parts, they are impervious to the kind of wear turbine or mechanical meters experience.

Principles of Operation
A "shedder" bar (also known as a bluff body) in the path of
Animation of vortex creation
Animation of vortices
(credit Cesareo de La Rosa Siqueira
via Wikipedia)
the flowing fluid produces flow disturbances called vortices. The resulting vortex trail is predictable and proportional to the fluid flow rate. This phenomena is know as the "Von Kármán vortex street" (see illustrations to the right). Sensitive electronic sensors downstream of the shedder bar measures the frequency of the vortices and produce a small electrical pulse with every vortex created. The electrical pulses also also proportional to fluid velocity and is the basis for calculating a volumetric flow rate, using the cross sectional area of the flow measuring device.

Typical Areas of Use
Vortex shedding flowmeters are used on steam, cryogenic liquids, hydrocarbons, air, feed water, and industrial gases.

Applications to Avoid
Splitting higher viscosity fluids into concordant vertices is extremely difficult due to the internal friction present, so using vortex shedding flowmeters on high viscosity media should be avoided. Also, avoid applications with low flow rates and low Reynolds Numbers, as the vortices created are unstable.

Consideration for Use
Consideration must be given to applications with low Reynolds numbers, as the generation of vortices declines at critical points of reduced velocity. Low pressure can also be a problem in this regard. Users must take Reynolds number, velocity, and density into consideration before choosing a vortex shedding flow meter. As always, it's best to discuss your application with an knowledgable support professional before specifying, purchasing, or installing this type of flowmeter.

Watch the video below for more information on vortex flow technology.


For more information on  vortex shedding flowmeters, visit https://www.meadobrien.com or call (800) 892-2769.

Monday, November 13, 2017

Inverted Submerged Bucket Steam Traps: How They Work

Diagram of the Armstrong Inverted Bucket Trap
Cutaway diagram of the Armstrong Inverted Bucket Trap.
The inverted submerged bucket steam trap is a mechanical trap that operates on the difference in density between steam and water. Steam entering the inverted submerged bucket causes the bucket to float and close the discharge valve.

Condensate entering the trap changes the bucket to a weight that sinks and opens the trap valve to discharge the condensate. Unlike other mechanical traps, the inverted bucket also vents air and carbon dioxide continuously at steam temperature.

This simple principle of condensate removal was introduced by Armstrong International in 1911. Years of improvement in materials and manufacturing have made today’s Armstrong inverted bucket traps virtually unmatched in operating efficiency, dependability and long life.

For more information on Armstrong steam traps, visit http://www.meadobrien.com or call (800) 892-2769.

Tuesday, October 31, 2017

Fixed Point Gas Monitoring

Fixed Point Gas Monitor
Fixed Point Gas Monitors (GfG)
In industry, the assessment and control of risk factors is a crucial element of process control. Commanding risk allows not only for peace of mind regarding environments involving hazardous materials, but also ensures ' and prioritizes - the safety of those who work with said materials. Fixed point gas monitoring tracks and repeatedly evaluates the levels of potentially toxic or flammable gases in an industrial environment, typically using electrochemical, infrared, or catalytic bead sensors. A central monitoring station allows for an entire facility to operate under consistent watch, as the array of gas monitors throughout a facility form a system. Typical environments which utilize fixed point gas monitoring include CNG filling stations, fleet maintenance buildings, wastewater lift stations and treatment plants, pipelines, and refineries, among others.

Due to the variation in facilities and associated industrial purposes, the applicability and customization of fixed point monitors must be adaptable. The gases typically monitored by fixed point systems are industrial staples. Natural gas (methane) and hydrogen are inherently dangerous to work with due to both their combustible nature and flammability. Carbon monoxide, hydrogen sulfide, and chlorine are especially dangerous to those who work in and around facilities where they are used or produced, while otherwise harmless gases such as nitrogen can cause oxygen displacement leading to asphyxiation. Around-the-clock is the only way to monitor and mitigate the potential impact of such volatile substances; thanks to automation, the ability to be constantly vigilant of threats related to gases is possible.

Sensing and evaluating these types of gases is a complex process, yet one which also showcases the powers of the associated technology. International certification standards like ATEX (derived from a French regulation acronym) and SIL (the safety integrity level) allow designers of gas detectors to match their products with the necessary parameters to ensure safe working environments. For example, one manufacturer's electrochemical gas sensor operates based on a principle involving two electrodes; the first electrode senses the toxic gas, and then the second electrode receives protons generated by the sensing electrode through an ion conductor. Output current which flows to an external circuit is proportional to the concentration of gas, therefore the current generated is measurable as an indicator of gas levels. Despite the fact that these sensors are primarily used in industry, there is also the potential for domestic applicability, automotive process control, and air quality control, among other uses. The different technological and practical applications of fixed point gas monitors allow for industry professionals to safely and capably navigate working environmental hazards for personnel and process protection.

For more information on fixed point gas detection, contact Mead O'Brien by visiting http://www.meadobrien.com or calling (800) 892-2769.

Tuesday, October 24, 2017

The Neles B1 Series Actuator

B1-Series
Neles B1 Series
Metso's Neles double acting and spring return B1-Series piston type actuators are designed for use in both modulating control and on-off service. The series B1C and B1J are designed to ISO 5211/1 when Metso linkages are utilized. These actuators offer an extremely long cycle life and are well suited to operate almost any type of rotary valve.

When "stay put" is the requirement, the double acting B1C series is the choice. This series is available in several sizes with torque outputs from 40 Nm to 100 000 Nm (29.5 lbf ft to 73 756 lbf ft) for maximum supply pressure of 10 bar (145 psi).

If a failure mode is required, the spring return B1J series should be selected. This line offers a self-contained spring cartridge to provide failure in either the open or closed position. The spring return actuators are available with a mid-range spring for a 4 bar (58 psi) supply range, a lighter spring for lower supply pressure of 3 bar (44 psi) range and a stronger spring for a 5.5 bar (80 psi) range. These actuators offer torque outputs from 25 Nm to 12000 Nm (18,5 lbf ft to 8851 lbf ft) for maximum supply pressure of 8.5 bar (124 psi).

Adjustable travel stops

As with any Neles pneumatic/hydraulic actuator, adjustable travel stops are standard for both the open and closed positions. End of stroke turning angle range is 85° to 95°. Optional travel stops 0° to 90° are also available.

Wear resistant bearings

High quality bearings provide support on the upper and lower portions of the lever arm to reduce friction and expand the life of both the lever arm and the housing.
Corrosion resistance

The epoxy painted actuators have housings of rugged cast iron, with light-weight aluminum cylinders anodized for added corrosion resistance. Travel stops are stainless steel.

Self-contained spring cartridge

The springs in the B1J actuator are contained in a cartridge for added reliability and easy maintenance.

Spring to open or close capability

The standard spring return actuator on the ball valve can provide spring-to-close or spring-to-open operation sim- ply by changing the mounting position by 90°. On a high performance butterfly valve, the standard unit offers spring-to-close operation. An optional B1JA model is available for spring-to-open requirements.

High-and-low temperature construction

The standard unit can be used in temperatures up to 70 °C (158 °F). High temperature construction is available for temperatures up to 120 °C (248 °F). The standard unit can be used down to -20 °C (-4 °F). A low temperature design is available for -40° to +70 °C (-40° to 158 °F ), arctic service please refer type coding.

High cycle option

For applications where very fast and high frequency operation is required.

ATEX compatibility

Actuator construction ATEX approved.

Oversized cylinder options

The oversized cylinders (B1C 60, 75, 602, 752) are used whenever the supply pressure is limited, thus the actuators can achieve the required torques with a lower supply pressure level.

Override options

Available override devices include a manual centerpiece handle, a manual handwheel override, and a manual hydraulic override for high torque applications.

Emergency shut-down

Emergency Shut-Down (ESD) valves utilizing B1J actuators are offered to assure operation in the event of a fire or plant malfunction.

For more information about Metso Neles actuators, visit http://www.meadobrien.com or call  (800) 892-2769.

Monday, October 23, 2017

Foxboro IMT25 Flow Transmitter Quick Start Video and IOM - Everything You Need

Model IMT25
The Foxboro® brand Model IMT25 Intelligent Magnetic Flow Transmitter uses a pulsed dc technique to excite the Models 8000A, 8300, 9100A, 9200A, 9300A, and 2800 Magnetic Flowtube coils, and convert the low level signal voltage to a digital, 4 to 20 mA, or pulse output.

FEATURES
  • Digital precision, stability, and resolution ensure top measurement performance.
  • Remote communication with HART communication protocol. (For FOUNDATION Fieldbus protocol, refer to PSS 1-6F5 B.)
  • Remote configuration using PC-based configurator or HART Communicator.
  • Local configuration using optional integral keypad, with backlighted, 2-line, LCD display.
  • Scaled pulse or frequency output.
  • Unidirectional or bidirectional flow.
  • Analog output programmable for unidirectional, bidirectional, or multiple input range.
  • Relay outputs with programmable functionality for alarms.
  • Contact inputs with programmable functionality for remote operation.
  • Automatic and manual zero lock.
  • Online diagnostic help.
  • Software configuration and totals protected in nonvolatile memory in the event of power loss.
  • Compact single or dual compartment.
  • Enclosure meets NEMA 4X and IEC IP66.
  • Field test mode using Foxboro Model IMTSIM Magnetic Flowtube Simulator.

Monday, September 11, 2017

How to Use the Ashcroft 1305 Deadweight Tester

Ashcroft 1305 deadweight tester
The Ashcroft 1305 deadweight tester provide a precise means for generating pressure with high accuracy that can be used as a primary calibration standard. The unit's built-in shuttle valve provides the means to control the rate of pressure increase, while precision adjustment is accomplished with an integral micro vernier displacement valve. 

This video below provides an overview of how to use the the Ashcroft 1305.

For more information on Ashcroft products, contact Mead O'Brien at (800) 892-2769 or visit http://www.meadobrien.com.


Friday, September 8, 2017

Voltage Ranging Solenoid Valve Coils are Rewriting Industry Standards

Voltage Ranging Valves
Voltage Ranging Solenoid Valves (ASCO)
New power management technology is rewriting industry standards for reliability and power consumption of solenoid valve coils. The new technology solenoid valves accepts both AC and DC voltages while improving performance. Available in 2-way, 3-way and 4-way, these solenoid valves are designed to handle most fluid control applications.

The enhanced valves are designed to be drop in replacements for existing valves. There is no change to functional attributes such as flow, pressure, ambient & fluid temperatures or physical attributes such as envelope size and face-to-face dimensions. If you're looking to just switch out a coil, enhanced coil kits are direct replacements for the old coil kits.

Here are the benefits to end customers:


Lower Power Consumption
  • 1.0 watt (DC version) & 1.5 watts (AC/DC versions)
  • Lowers energy cost up to 80% compared to standard solenoid valves 
RoHS 2 Compliant
  • Satisfies CE Directives 2002/95/EC and 2001/65/EU (RoHS 2) for the restriction of hazardous substances 
Supervisory Current Compatible
  • Suitable for systems employing supervisory currents not exceeding the following drop-out currents:
    • 20mA (12-24V DC), 15mA (24-120V AC/DC) and 7mA (100-240V AC/DC) 
  • Also suitable with devices having leakage currents not exceeding the drop-out currents noted above. 
Broad Voltage Ranges Reduce Inventory
  • Available in 24-120V AC/DC, 100-240V AC/DC & 12-24V DC 
  • Covers hundreds of global voltage requirements
  • Simplifies product selection and reduces complexity
  • Lowers inventory cost by eliminating need to stock both AC & DC products
  • Includes 125VDC battery (AC/DC versions) & 24VDC battery (DC version) 
DC Performance Increased Up to 500% To Match AC Ratings 
  • Transition from AC to DC without sacrificing performance
  • Eliminates the need for separate AC & DC output cards
  • Simplifies control schemes 
Integrated Surge Suppression
  • Prolongs the life of the coil by suppressing external voltage spikes
  • Lowers system cost by eliminating the need for additional surge protection 
Fit For Use In Rugged and Demanding Environments
  • Wide ambient temperature range for hot and cold environments
  • Enclosure Types 1 through 4X for indoor and outdoor applications o Optional Class 1, Division 2 coils available for hazardous locations 
No AC Hum
  • Ideal for applications requiring quiet operation
Contact Mead O'Brien at (800) 892-2769 or visit http://www.meadobrien.com for more information.

Thursday, August 31, 2017

Direct Steam Injection Humidifier Replacement in Large Hospital

Direct Steam Injection Humidifier Replacement in Large Hospital
Direct Steam Injection Humidifier Replacement
at St. Louis Children's Hospital
The St. Louis Children’s Hospital is one of the premier children’s hospitals in the United States. It serves not just the children of St. Louis, but children and their families from across the world. The hospital provides a full range of pediatric services to the St. Louis metropolitan area and primary service region covering six states. As the pediatric teaching hospital for Washington University School of Medicine, the hospital offers nationally recognized programs for physician training and research. The hospital employees 3,000 people as well as 800 medical staff members. There are also 1,300 auxiliary members and volunteers on-site.

St. Louis Children’s Hospital was undergoing a significant renovation and determined that the original direct steam injection humidifiers that were installed over 30 years ago needed to be replaced. Within 30 years, they had only experienced minor issues due to the age and use of the humidifiers. Most issues were labeled as manifold o-ring leaks or actuator leakage (either seal kits or diaphragms).

St. Louis Children’s Hospital consulted with their local Armstrong representative, Mead O’Brien, and looked at using direct steam injection humidifiers with electric actuators versus the atmospheric steam generating humidifier. Due to the maintenance, space concerns, and, most importantly, the controllability, Mead O’Brien suggested direct steam injection humidifiers.

When replacing humidifiers during a renovation it is important to analyze the absorption distance. There are many different variables that can affect the absorption distance and, in this case, guidelines and regulations have changed over 30 years since original installation. The amount of outside air brought into the space directly affects the RH levels, and in the healthcare industry, the minimum requirement of fresh air has changed multiple times in the past 30 years. Because of this, some installations required the use of multiple manifolds to shorten the absorption distance.

During this first phase of the renovation, thirty-nine (39) new steam humidifiers were installed. Thirty-four more we supplied the following year..

In addition, the following Armstrong products were also installed:
  • Six Pressure Reducing Valves 
  • Three Electric Condensate Pumps 
  • One Armstrong Flo-Rite
  • Five VERIS Flow Meters
Because of the customer’s relationship with their local Armstrong representative, St. Louis Children’s Hospital received a quality solution that was designed to meet all of their needs and will be supported by Armstrong for many years to come.

Click this link to download the PDF version of this steam injection humidifier application note.

Tuesday, August 29, 2017

Hygienic Sight Flow Indicators for Pharmaceutical, Bio-pharmaceutical, and Food Processing

Hygienic Sight Flow Indicator
Hygienic Sight Flow Indicator
Jacoby-Tarbox, a division of Clark Reliance, manufactures a complete line of tubular and bulls-eye sight flow indicators manufactured specifically for pharmaceutical, bio-pharmaceutical, food, and other processing systems demanding cleanliness and maximum hygienic conditions.





Their tubular glass design allows full 360° view of the cylinder and they achieve controlled intrusion meeting ASME-BPE’s strictest requirements by employing:
  • ASME BPE dimensions and Design Principles
  • Precision-Bore borosilicate glass 
  • Tightly tolerance EHEDG inspired O-ring capture
Watch the video below for a more detailed understanding. You can download a brochure about these hygienic sight flow indicators here.


For more information, contact Mead O'Brien at http://www.meadobrien.com or call (800) 892-2769.


Monday, August 21, 2017

HART Communication Protocol - Process Instrumentation

HART process instruments
Process instrument with HART protocol (Foxboro)
The Highway Addressable Remote Transducer Protocol, also known as HART, is a communications protocol which ranks high in popularity among industry standards for process measurement and control connectivity. HART combines analog and digital technology to function as an automation protocol. A primary reason for the primacy of HART in the process control industry is the fact that it functions in tandem with the long standing and ubiquitous process industry standard 4-20 mA current loops. The 4-20 mA loops are simple in both construction and functionality, and the HART protocol couples with their technology to maintain communication between controllers and industry devices. PID controllers, SCADA systems, and programmable logic controllers all utilize HART in conjunction with 4-20 mA loops.

HART instruments have the capacity to perform in two main modes of operation: point to point, also known as analog/digital mode, and multi-drop mode. The point to point mode joins digital signals with the aforementioned 4-20 mA current loop in order to serve as signal protocols between the controller and a specific measuring instrument. The polling address of the instrument in question is designated with the number "0". A signal specified by the user is designated as the 4-20 mA signal, and then other signals are overlaid on the 4-20 mA signal. A common example is an indication of pressure being sent as a 4-20 mA signal to represent a range of pressures; temperature, another common process control variable, can also be sent digitally using the same wires. In point to point, HART’s digital instrumentation functions as a sort of digital current loop interface, allowing for use over moderate distances.

HART in multi-drop mode differs from point to point. In multi-drop mode, the analog loop current is given a fixed designation of 4 mA and multiple instruments can participate in a single signal loop. Each one of the instruments participating in the signal loop need to have their own unique address.

Since the HART protocol is a standardized process control industry technology, each specific manufacturer using HART is assigned a unique identification number. This allows for devices participating in the HART protocol to be easily identified upon first interaction with the protocol. Thanks to the open protocol nature, HART has experienced successive revisions in order to enhance the performance and capabilities of the system relating to process control. The standardization of “smart” implementation, along with the ability to function with the legacy 4-20 mA technology and consistent development, has made HART a useful and popular component of the process measurement and control industry framework.

Have a question about HART? Contact Mead O'Brien by visiting this link, or call
(800) 892-2769.

Sunday, August 13, 2017

The Basics of Process Control Instrument Calibration

Process Control Instrument CalibrationCalibration is an essential part of keeping process measurement instrumentation delivering reliable and actionable information. All instruments utilized in process control are dependent on variables which translate from input to output. Calibration ensures the instrument is properly detecting and processing the input so that the output accurately represents a process condition. Typically, calibration involves the technician simulating an environmental condition and applying it to the measurement instrument. An input with a known quantity is introduced to the instrument, at which point the technician observes how the instrument responds, comparing instrument output to the known input signal.

Even if instruments are designed to withstand harsh physical conditions and last for long periods of
time, routine calibration as defined by manufacturer, industry, and operator standards is necessary to periodically validate measurement performance. Information provided by measurement instruments is used for process control and decision making, so a difference between an instruments output signal and the actual process condition can impact process output or facility overall performance and safety.

Instrument Calibration LabIn all cases, the operation of a measurement instrument should be referenced, or traceable, to a universally recognized and verified measurement standard. Maintaining the reference path between a field instrument and a recognized physical standard requires careful attention to detail and uncompromising adherence to procedure.

Instrument ranging is where a certain range of simulated input conditions are applied to an instrument and verifying that the relationship between input and output stays within a specified tolerance across the entire range of input values. Calibration and ranging differ in that calibration focuses more on whether or not the instrument is sensing the input variable accurately, whereas ranging focuses more on the instruments input and output. The difference is important to note because re-ranging and re-calibration are distinct procedures.

In order to calibrate an instrument correctly, a reference point is necessary. In some cases, the reference point can be produced by a portable instrument, allowing in-place calibration of a transmitter or sensor. In other cases, precisely manufactured or engineered standards exist that can be used for bench calibration. Documentation of each operation, verifying that proper procedure was followed and calibration values recorded, should be maintained on file for inspection.

As measurement instruments age, they are more susceptible to declination in stability. Any time maintenance is performed, calibration should be a required step since the calibration parameters are sourced from pre-set calibration data which allows for all the instruments in a system to function as a process control unit.

Typical calibration timetables vary depending on specifics related to equipment and use. Generally, calibration is performed at predetermined time intervals, with notable changes in instrument performance also being a reliable indicator for when an instrument may need a tune-up. A typical type of recalibration regarding the use of analog and smart instruments is the zero and span adjustment, where the zero and span values define the instruments specific range. Accuracy at specific input value points may also be included, if deemed significant.

The management of calibration and maintenance operations for process measurement instrumentation is a significant factor in facility and process operation. It can be performed with properly trained and equipped in-house personnel, or with the engagement of highly qualified subcontractors. Calibration operations can be a significant cost center, with benefits accruing from increases in efficiency gained through the use of better calibration instrumentation that reduces task time.

Monday, July 31, 2017

A Very Unique "No Straight Run Required" Flowmeter

VERIS Accelabar
VERIS Accelabar Detail
The VERIS Accelabar® is a unique flow meter that combines two differential pressure technologies to produce performance never before attainable in a single flow meter.

The VERIS Accelabar® is capable of measuring gases, liquids, and steam at previously unattainable flow rate turndowns—with no straight run requirements.

No Straight Run Required

The VERIS Accelabar® can be used in extremely limited straight run piping configurations. All necessary straight run is integral to the meter. The stabilization and linearization of the velocity profile within the throat of the nozzle eliminates the need for any upstream or downstream pipe runs.

Read the document below for more information or download the VERIS Accelabar® PDF from Mead O'Brien's website here.

Monday, July 24, 2017

Mead O'Brien: Experts in Valves, Valve Automation, Steam & Hot Water Systems, Process Instruments

Mead O’Brien specializes in valves & valve automation, steam & hot water products and systems, instrumentation products, skid designs, field services, surveys, assessments, and consulting.

Product Focus:
  • Valves, valve automation and control
  • Steam and hot water products and systems
  • Instrumentation and controls
For more information, visit http://www.meadobrien.com or call  (800) 892-2769.

Please pardon our little shameless self-promotion. Thanks for watching this short video highlighting Mead O'Brien products.