Showing posts with label Virginia. Show all posts
Showing posts with label Virginia. Show all posts

Tuesday, March 13, 2018

The Ideal Flow Monitoring System for a Drinking Water Supply Network

The ideal drinking water flow monitoring system.
Wouldn't it be great if you had a closely woven system of measuring points that monitor flow rates in the drinking water supply network as seamlessly as possible and leaks and hydrological problem zones would be detected and corrected as quickly as possible?

Unfortunately the reality looks somewhat different. Installation of conventional flow measuring points in a drinking water supply network incurs high costs and an enormous amount of effort to maintain.


FLEXIM is a technology leader in the field of non-invasive flow measurement with clamp-on ultrasonic technology. FLEXUS clamp-on ultrasonic systems measure according to the transit time difference method. Since the transducers are mounted on the outside of the pipe no interventions in the pipeline system are necessary. the drift free and long-term stable acoustic measuring method detects even the smallest flows, even those that lie below the response threshold of conventional flow meters. Therefore, fluxes is the ideal instrument for monitoring minimum flow rates at night, and thus the key to effective consumption and leakage monitoring.

With FLEXUS, a flow measuring point can be conveniently setup within half a working day without supply interruptions with out affecting traffic, and without a heavy lifting device.  For the installation of the ultrasonic measuring system, only temporary access to the pipe has to be created.  The service engineer first checks the pipe dimensions. Sturdy mounting devices made of stainless steel ensure that the flow transducers are permanently stable when installed. Even on the transducers themselves, nothing can break. The cable and sensor are firmly connected. No plug can come loose. Water or dirt cannot penetrate anywhere. The ultrasonic transducers have IP68 protection and can operate continuously underwater. Coupling pads, made of elastic plastic, ensure permanent optimal acoustic coupling to the pipe without any wear. Thanks to their unique internal temperature compensation, FLEXIM transducers do not show any drift during temperature fluctuations. Setup of the measuring point on the pipe is completed by positioning and fixing the ultrasonic transducers. Now only the connection to the measuring transmitter, housed in the switch cabinet, has to be created. The calibration data of carefully paired and calibrated transducers are stored on one chip and are automatically transferred to the measuring transmitter. A zero point calibration on site is not necessary. Where nothing flows, FLEXUS reliably measures zero.

Measurement in Progress

The measuring results are either transmitted by cable or wirelessly via GSM to the process control system. Practical self-diagnosis functions allow for safe evaluation of the measurement quality. Done. Now the measuring point can be refilled underground since the pipe line remained completely intact. There was no need to flush the pipe and no need for the final leak test. In the office, the measured values can be visualized and evaluated on a computer.

Sunday, February 25, 2018

Bently Nevada 3500 Series Machinery Monitoring System Datasheet

Bently Nevada 3500 Series Machinery Monitoring System
Machine condition monitoring combines hardware, software, and service and support – providing a broad, connected view of your operations. Together, they enable your plant to mitigate risk, boost safety, and reduce maintenance costs, while improving equipment reliability, uptime, and efficiency.

Hardware monitoring systems and sensors protect your equipment and collect rich condition monitoring and diagnostic data for analysis. Condition monitoring and diagnostics software connects real-time and historical data from production equipment to help you anticipate failure before it occurs. With scalable deployment and ongoing support service offerings, you can ensure that you’re maximizing the value of your condition monitoring program.

The Bently Nevada 3500 Monitoring System provides continuous, online monitoring suitable for machinery protection and asset condition monitoring applications. It represents our most capable and flexible system in a traditional rack-based design and offers numerous features and advantages not provided in other systems.

Download a PDF version of the Bently Nevada 3500 System datasheet here, or quickly review the embedded document below.

For more information, contact Flow-Tech in Maryland by calling 410-666-3200, in Virginia by calling 804-752-3450, or by visiting

Friday, February 16, 2018

Campus Metering: Advantages of Using V-Cone for Measuring Chilled Water & Steam in Hospitals, Universities, and Institutions

McCrometer's V-Cone
Typical diagram of V-Cone installation.
(Click for larger view).
McCrometer's V-Cone® Flow Meter is an advanced differential pressure instrument, which is ideal for use with liquid, steam or gas media in rugged conditions where accuracy, low maintenance and cost are important. The V-Cone is especially useful in tight-fit and retrofit installations. 

In most instances the use of V-Cones associated with chillers for chilled water in large institutional users is a matter of space, accuracy, and turndown. The V-Cone needs very little upstream and downstream piping requirements, allowing it to be used in spaces where other meters cannot be used, or to replace existing flowmeters that never proved accurate because of space limitations. 

In many large universities and other facilities, such as hospitals and airports, across the U.S., the reason for initial interest and subsequent purchases of V-Cones to measure Chilled Water was to fit within the confines of the existing and new buildings that were being used to house the chillers. Additionally, the second most important reason was the delivered accuracy. In the past, most usage had been ignored, but with the rising costs associated with cooling, each individual building must be accountable for individual use. This is just good fiscal responsibility and management from an energy balance standpoint. Turndown was an issue because of seasonal swings in usage based on climate and population in the buildings at any particular time. Therefore, the meters needed to be able to have a large flow span (turndown), which remained accurate during continuous use.
McCrometer's V-Cone
Internal view of V-Cone.

V-Cones have recently been selected for Steam service for mostly the same reasons as they are selected for Chilled Water. Space limitations in new and/or older buildings are a serious concern. V-Cones have the smallest piping requirements of practically any flowmeter and continue to deliver accurate measurement, so they are fiscally responsible and cost effective. Additionally, in steam, they allow condensate and/or other small particulate matter to pass without affecting the measurement, thus giving much better accuracy instantaneously and over time. 

They are very rugged flowmeters which require little or no maintenance, and have a very long expected life even in “tough” service like steam. They can be designed with great turndown (span) and therefore can accommodate changes in flowrates based on demand, seasonal or from other factors.

For more information on V-Cone flowmeters, contact Flow-Tech in Maryland at 410-666-3200, in Virginia at 804-752-3450, or by visiting

Wednesday, February 7, 2018

How To Select a Gas Flow Meter for Your Application

Gas Flow Meter

Here is some very good, basic advice, courtesy of FCI (Fluid Components International) on selecting a gas flow meter.

Match your application to the appropriate measurement technology. Accurate flow measurement starts with selecting the best flow meter technology for your application. Every application has a set of requirements that narrows the choice of technologies. For example, thermal dispersion might work best in a dirty process gas, like biogas, because this technology provides no-moving-parts reliability, direct mass flow measurement, and wide range ability. However, positive displacement might be the best technology choice for the custody transfer of natural gas.

An Instrument Specification Sheet is a good place to find information that will help select the most appropriate flow meter technology for an application. This sheet identifies the application's process temperature and pressure, gas composition, piping configuration, accuracy requirements, and more.

Now forward your application information to vendors that offer the most appropriate flow meter technology. Be sure to include as much information about the application as possible and highlight your realistic performance expectations. Do not request 0.5 percent accuracy if the application needs only 5 percent accuracy. Ask these vendors to evaluate your application and provide a product recommendation. Use the information you receive to revise your specification (if necessary), finalize your preferred vendor list, and prepare your request-for-quote.

FCI flowmeters
Contact Flow-Tech for any flow meter application you may have. Our support engineers are ready to help.

In Maryland - 410-666-3200
In Virginia - 804-752-3450

Monday, January 29, 2018

Understanding Hydrostatic Pressure in Process Control

Hydrostatic pressure transmitter
Transmitter used to measure
hydrostatic pressure. (Yokogawa)
The pressure exerted by a fluid material in a vessel is directly proportional to its height multiplied by its density.

Hydrostatic pressure, or head pressure, is the force produced by a column of material. As the height of the material changes, there is proportional change in pressure. To calculate hydrostatic pressure, the density of the material is multiplied by the height of the column. The level of fluid in a column can be determined by dividing the pressure value by the density of the material.

To find pressure in a column of water, a gauge placed at the bottom of the vessel. With the water having a density of 0.0361 pounds per cubic inch, the level of the fluid is calculated by dividing the head pressure by the density of the fluid.

An example to determine the level measurement of a column of water that is 2 feet tall in diameter of 0.5 feet is solved by the following steps. The first step is measuring the weight of the vessel. Next measure the weight of the vessel with fluid. The weight of the fluid is determined by subtracting the weight of the vessel from the weight of the vessel with fluid. The volume of the fluid is then derived by dividing the fluid weight by the density of the fluid. The level of the fluid is finally calculated by dividing the volume of the fluid by the surface area.

Hydrostatic pressure can only be calculated from an open container. Within a closed vessel, or pressurized vessel, the vapor space above the column of material adds pressure, and results in inaccurate calculated values. The vessel pressure can be compensated for by using a differential pressure transmitter. This device has a high pressure side input and a low pressure side input. The high-pressure input is connected to the bottom of the tank to measure hydrostatic pressure. The low-pressure input of the differential pressure transducer is connected to the vapor space pressure. The transducer subtracts the vapor pressure from the high-pressure. Resulting is a value that represents the hydrostatic head proportional to the liquid level.

Saturday, January 20, 2018

Tank Overfill Protection

Tank Level Control
Tank Level Control Diagram (Yokogawa)
Protecting against tank overfill allows for process control industry professionals to mitigate potential risk to both their processes and process materials. Different products present different risks regarding tank overfill, but the work of preventing overfill is a universal component of safety, procedural effectiveness, and maximization of resources. If tank overfill does occur, a number of potential negative outcomes could result, especially in the cases of wastewater, chemicals, and petroleum products. Everyone, from management to methodology, needs to be working from the same ideal regarding safety as an inherent priority of process control.

Instead of solely focusing on tank overfill prevention, many corporations have developed written instructions for every individual operator in an organization. Not only do these standards adhere to regulations, but they also meet environmental standards while eliminating accident risk. Six Sigma is an example of data-driven management meant to eliminate potential defects in safety procedures. The idea of pursuing perfection in all components of an organization may originally seem far away from overfill protection. However, previous attempts to confront tank overfill without consideration for the larger organization narrowed operational windows to only consider one part of the system.

Expanding this system to include root causes of overfill prevention instead of solely the mechanisms for prevention has resulted in a more holistic approach to the integration of safety standards. Regulatory requirements for tank metrics, how to operate aboveground versus below ground tanks, and process material specific guidelines are combined with internal company codes. Those two elements are then fused with the Recognized and Generally Accepted Good Engineering Practices which are developed by industry associations. The tri-part approach has resulted in a more collaborative effort to combat tank overfill problems.

One metric employed to prevent tank overfill-related dangers is to measure whether or not the tank in question has the appropriate room to accommodate abnormal process behavior. Considerations such as these mesh with evaluations of pipe size and whether or tanks need to be connected to relief tanks. Assessment of both operational and insurance risk means the entirety of the process must be understood and evaluated so that the interaction between the process materials can be predicted and then mitigated. Whether these components are raw materials, system components, or final products in the latter stages of the process, automated systems combined with operator diligence based on established methodology is the best way to prevent overfill and associated dangers.

To discuss your tank level control and overfill requirements, contact Flow-Tech at or call 410-666-3200 in Maryland, or 804-752-3450 in Virginia.

Saturday, January 13, 2018

How to Adjust Alarms and Pointer for Brooks Instrument Models MT3809G & MT3810G Variable Area Flowmeters

Here are the instructions for the removal and reinstallation of the XP housing indicator cover, and
how to adjust alarms and pointers for Brooks Instrument models MT3809G & MT3810G variable area flowmeters:

Warning: If it becomes necessary to service or remove the instrument from the system, power to the device is disconnected at the power supply.
  1. To begin make sure the float is at rest and there isn’t flow going through the meter.
  2. Using your hands or a strap wrench turn the cover counter clockwise to remove the cover from the housing.
  3. Remove the cover from the housing. The gasket should stay attached to the groove in the housing.
  4. Using a flat blade screwdriver with a 1/8" blade, hold the red alarm pointer and turn the screw counterclockwise to loosen the pointer, slide it to desired position on scale and tighten screw.
  5. Using a flat blade screwdriver with a 1/8" blade, hold the pointer and turn the screw to align with the “R” on the scale. It may take a few adjustments to get the pointer aligned to the “R”.
  6. To replace the cover, place the cover against the housing and turn the cover clockwise. Note, it will take several rotations to tighten the cover and the cover must be in contact with the gasket to keep a watertight seal.

MT3809G & MT3810G variable area flowmeter
Click for larger view.
For additional assistance, contact Flow-Tech in Maryland at 410-666-3200 or Virginia at 804-752-3450 or visit

Thursday, December 28, 2017

Measurement and Calibration Principle of FLEXIM's Non-Invasive Ultrasonic Flowmeter

The principle of FLEXIM's ultrasonic flow measurement of liquids and gases relies on the propagation of ultrasonic wave signals into the medium. This measurement method exploits the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium. Similar to a swimmer swimming against the current, an ultrasonic signal moves slower against the flow direction of the medium than when in flow direction.

For the measurement, two ultrasonic pulses are sent through the medium, one in the flow direction, and a second one against it. The transducers are alternatively working as an emitter and a receiver. The transit-time of the ultrasonic signal propagating in the flow direction is shorter than the transit-time of the signal propagating against the flow direction. A transit-time difference, Δt, can thus be measured and allows the determination of the average flow velocity based on the propagation path of the ultrasonic signals. An additional profile correction is performed by our proprietary algorithms, to obtain an exceptional accuracy on the average flow velocity on the cross-section of the pipe - which is proportional to the volume flow, and when temperature and pressure compensated, to the mass flow.

Since ultrasounds propagate in solids, the transducers can be mounted onto the pipe. The measurement is therefore non-invasive, and thus no cutting or welding of pipes is required for the installation of the transducers.

For more information about FLEXIM, contact Flow-Tech at 410-666-3200 or visit

Wednesday, December 20, 2017

Yokogawa Pressure eBook - A Basic Guide to Understanding Pressure

The impact of pressure on industrial processes would be difficult to understate. Pressure is an element of process control that can affect performance and safety. Understanding pressure concepts and how to effectively measure pressure within a process are key to any operator's success.

Yokogawa, a globally recognized leader in process measurement and control, has made available a handbook on pressure that covers a range of useful topics. The content starts with the very basic concepts and moves quickly to practical subjects related to process measurement and control.

The handbook will prove useful to readers at all levels of expertise. Share your process measurement challenges with application specialists, combining your process knowledge with their product application expertise to develop effective solutions.

Download your own copy of the Pressure Handbook here, or view online below.

Wednesday, December 13, 2017

Draeger Tubes & Chip Measurement System Handbook

Draeger is the leader in industrial gas and vapor analysis and have developed more detection devices and tubes for more applications than any other gas detection company.

Draeger sampling tubes allow identification and measurement of different substances even under difficult conditions.

Draeger Chip Measurement System (CMS) combines Chips for measure specific substances with an electronic analyzer for easy-to-use spot-measurement. The analyzer combines an optical system for analyzing the color reaction with a mass flow controller and pump system.

Download the Draeger -Tubes & Chip Measurement System Handbook here.

Thursday, November 30, 2017

Differential Flowmeters: How They Work

Differential Flowmeters
The differential flow meter is the most common device for measuring fluid flow through pipes. Flow rates and pressure differential of fluids, such as gases vapors and liquids, are explored using the orifice plate flow meter in the video below.

The differential flow meter, whether Venturi tube, flow nozzle, or orifice plate style, is an in line instrument that is installed between two pipe flanges.

The orifice plate flow meter is comprised the circular metal disc with a specific hole diameter that reduces the fluid flow in the pipe. Pressure taps are added on each side at the orifice plate to measure the pressure differential.

According to the Laws of Conservation of Energy, the fluid entering the pipe must equal the mass leaving the pipe during the same period of time. The velocity of the fluid leaving the orifice is greater than the velocity of the fluid entering the orifice. Applying Bernoulli's Principle, the increased fluid velocity results in a decrease in pressure.

As the fluid flow rate increases through the pipe, back pressure on the incoming side increases due to the restriction of flow created by the orifice plate.

The pressure of the fluid at the downstream side at the orifice plate is less than the incoming side due to the accelerated flow.

With a known differential pressure and velocity of the fluid, the volume metric flow rate can be determined. The flow rate “Q”, of a fluid through an orifice plate increases in proportion to the square root the pressure difference on each side multiplied by the K factor. For example if the differential pressure increases by 14 PSI with the K factor of one, the flow rate is increased by 3.74.

Monday, November 27, 2017

Small Line Size Flow Measurement without Moving Parts

ST75 Series

Excellent for Gas Sub-Metering, Boiler Fuel-To-Air Mixing, Chemical Injection & Much More

Plant and process engineers who need accurate flow detection or measurement of air, gases, or liquids in smaller pipe sizes will find several diverse flow instrument solutions available from Fluid Components International (FCI).  Using advanced, ultra-reliable thermal dispersion flow measurement technology with no-moving parts, FCI’s ST75 Series and ST100L Air/Gas Flow Meters and FLT93L Flow Switch provide ideal solutions for use in 0.25 to 2 inch (DN6 to DN50) pipe or tubing. They excel where low flows, wide-turndowns, dirty fluids, HazEx or harsh installations are among the applications factors.

These flow instruments offer many advantages for service in a wide range of applications: plant, building or lab gas sub-metering, small inlet air/gas feed lines for boilers, gas relief valve monitoring, chemical injection, compressed air systems, CO-Gen or CHP gas fuel measurement and control, sampling systems, and more.  Many small process line applications are difficult to measure reliably with high repeatability due to variations in temperature and pressure, and have wide flow rates.  FCI’s thermal flow meters and switches are unaffected by, or have on-board compensation for, temperature and pressure changes and, in addition to superior detection of low flow rates, provide 100:1 turndown as a standard feature.  FCI’s highly reliable, small line air/gas flow meters and aid/gas/liquid flow switches combine state-of-art electronics technology with application fluid-matched flow sensors and laboratory calibration in rugged packages designed for the most demanding plant operating environments. 
FLT93L Flow Switch
FLT93L Flow Switch

Thermal flow sensor technology developed by FCI relies on the relationship between flow rate and the cooling effect.  With no moving parts and minimal invasiveness, these meters and switches provide a highly repeatable, accurate, low cost, easy-to-install solution and there’s virtually no maintenance required over a long life.  FCI’s ST75 Series Air/Gas Flow Meters are ideal for lines sizes from 0.25 (6mm) to 2 inches (51mm).  Gas or air measurement accuracy is available up to 1% of reading, ±0.5% full scale. The ST75 Meters feature a wide 100:1 turndown and will measure from 0.01 to 559 SCFM [0,01 to 950 NCMH] depending on pipe size.

The meter’s electronics are housed in a rugged, IP67 rated enclosure with dual conduit ports in either NPT or M20 threading. The instrument comes standard with dual 4-20 mA outputs and a 500 Hz pulse output. The models ST75A and ST75AV include HART as well as NAMUR compliant 4-20 mA outputs and a SIL compliance rating and 2 year warranty.  Global agency approvals for Div.1/Zone 1 HazEx installations include FM, FMc, ATEX, IECEx, EAC and more. 

The best-in-class ST100L Air/Gas Flow Meter is a next generation instrument that combines feature- and function- rich electronics with advanced flow sensors. It is designed in a spool piece configuration in 1-, 1.5- or 2-inch tubing, schedule 40 and schedule 80 piping.  It measures air/gas flows from 0.0062 to 1850 SCFM [0.01 to 3,140 Nm3/h] with superior accuracy to ± 0.75% reading, ± 0.5% full scale; and repeatability of ± 0.5% reading. 

ST100L Air/Gas Flow Meters
ST100L Air/Gas Flow Meters
Whether the plant’s output needs are traditional 4-20 mA analog, frequency/pulse or advanced digital bus communications such as HART, Foundation Fieldbus, PROFIBUS, or Modbus, the ST100L is available with any of them.  Its digital bus communications also are certified and registered devices with HART and Foundation Fieldbus.  Global approvals include:  FM, FMc, ATEX, CE, CSA, IECEx, EAC, NEPSI and Inmetro.  It SIL compliant and is an all-welded design to ensure no leakage when used with volatile gases like hydrogen. 

For applications lacking enough straight-run, both ST75 Series and ST100L can be supplied with Vortab flow conditioning built-in to the spool-piece flow body. Its wide selection of available process connections include male and female threaded and flanges are standard.   The FLT93L Flow Switch is a dual function, dual trip point/alarm point precision switch.  It is field settable for trip point on flow rates and temperature, and as any high or low value of either flow or temperature.  The FLT93L’s setpoint range is: 0.015 to 50 cc/sec [0.0009 to 3 fps] for water-based liquids; 0.033 to 110 cc/sec [0.002 to 6.6 fps] for hydrocarbon-based liquids; and 0.6 to 20,000 cc/sec [0.036 to 1198 fps] for air and gases.

Trip point accuracy is ± 0.5% reading or ± 0.04 fps [± 0.012 mps] (whichever is higher) in liquids and ± 0.5% reading or ± 2 fps [± 0.06 mps] (whichever is higher in air or gases.   The FLT93 has been designed for use and longest service life in the most rugged, harsh operating environments. It is available in both aluminum and stainless steel IP67 rated housings, carries HazEx agency approvals for FM, FMc, ATEX, IECEx, EAC, Inmetro, NEPSI, meets CRN and European PED and is SIL 2 compliant. It is available in numerous wetted materials and process connection options, and has universal DC/AC power supply. 

For more information on Fluid Components, Inc. products in Maryland and Virginia, contact Flow-Tech at 410-666-3200 or visit

Monday, November 20, 2017

Understanding Mass Flow Controller (MFC) Metrology & Calibration

Mass flow controllers (MFCs) precisely deliver fluids, mainly process gases, into bioreactors and other process systems. The stable, reliable and repeatable delivery of these gases is a function of four key factors:
  • The quality and sophistication of the MFC’s design.
  • The application set-up, which covers the acceptable level of  fluid delivery accuracy a given process requires.
  • Metrology: what specific techniques are used to test, measure and con rm MFC accuracy.
  • Calibration checks: how an MFC is calibrated on an ongoing basis.
It’s common to extensively investigate an MFC’s technical characteristics and capabilities, as well as analyze and ensure that the MFC technology chosen fully satis es each operation’s unique process requirements. Equally important is the role that metrology, which includes testing reference standards and calibration practices, plays in the performance and long-term value of biopharmaceutical process equipment MFCs. In the eBook below, we will provide a deeper understanding of metrology’s role in how MFCs are used and managed in these systems. This includes:
  • The key elements of MFC accuracy and why calibration is important
  • How MFC calibration reference standards are used and why selecting the right standard matters
  • The role that “uncertainty” plays in calibrating MFCs
  • Factors that can lead to improper calibration
Please review the eBook embedded in this post below, or if you prefer, you can download your own PDF copy here - Understanding Mass Flow Controller (MFC) Metrology & Calibration. For more information about MFC's, contact Flow-Tech at or call 410-666-3200.

Saturday, November 11, 2017

Clamp-on, Transit-time Difference Ultrasonic Flowmeters Ideal for HVAC Retrofit and New Construction

Transit-time Difference Ultrasonic Flowmeters
Transit-time Difference Ultrasonic Flowmeters (Flexim)
There are many reasons for large commercial buildings, medical centers, museums, airports, sports complexes, federal institutions and military complexes to invest in building energy optimization efforts. Better and more efficient operation of HVAC equipment can reduce the buildings energy and operational costs significantly.

Controlling flow, temperature and pumps can provide energy cost savings of over 20%. Many campus energy managers believe that the biggest user of energy in any complex is the HVAC system, and the key to saving energy in HVAC systems is an accurate and reliable flow metering capability.

Better efficiency of the heating and cooling infrastructure of a building also leads to more environmentally friendly buildings, something that has become a social prerogative of building owners and operators.  Older buildings were not built with BTU meters as metering requirements were added to buildings through increased regulations.

Submetering the buildings heating and cooling systems have become increasingly more important, as building owners are both mandated to meter these utilities and have a financial interest in the accuracy of these BTU measurements. The problem historically is that nearly all flow meters are designed for gradual failure due to direct contact with the fluids they are monitoring and the particulate accumulation on the sensors.

Clamp-on, transit-time difference ultrasonic flowmeters are the ideal retro-fit flowmeter, and also should receive strong consideration for new building construction. Transit-time difference ultrasonic clamp on flowmeters exploit the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium - kind of like a swimmer swimming against the current. The signal moves slower against the flow than with it.

How Transit-time Difference Ultrasonic Flowmeters Work

The flowmeter sends ultrasonic pulses through the process medium - one in the same direction as the
flow and one in the opposite direction. The flowmeter's transducers alternate as emitters and receivers. The transit time of the signal going with the flow is shorter than the one going against. The flowmeter measures transit-time difference and determines the average flow velocity of the process medium. Since ultrasonic signals propagate in solids, the flowmeter can be conveniently mounted directly on the pipe and measure flow non-invasively.

Contact Flow-Tech with your questions about any flow measurement application. Reach them at 410-666-3200, or visit

Tuesday, October 31, 2017

Understanding HART Protocol

A current loop using sensing and
control transmission with HART protocol
overlaid on the 4–20 mA loop.
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 ì0î. 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.

Image courtesy of  Dougsim (Own work) [CC BY-SA 4.0], via Wikimedia Commons

Tuesday, October 24, 2017

Vibration Analysis in Manufacturing and Process Control

Vibration graph
Image courtesy of Wikipedia
As all of us who ride or drive an automobile with some regularity know, certain mechanical faults or problems produce symptoms that can be detected by our sense of feel. Vibrations felt in the steering wheel can be an indicator of an out-of-balance wheel or looseness in the steering linkage. Transmission gear problems can be felt on the shift linkage. Looseness in exhaust system components can sometimes be felt as vibrations in the floorboard. The common thread with all these problems is that degeneration of some mechanical device beyond permissible operational design limitations has manifested itself by the generation of abnormal levels of vibration. What is vibration and what do we mean by levels of vibration? The dictionary defines vibration as “a periodic motion of the particles of an elastic body or medium in alternately opposite directions from the position of equilibrium when that equilibrium has been disturbed or the state of being vibrated or in vibratory motion as in (1) oscillation or (2) a quivering or trembling motion.”

The key elements to take away from this definition are vibration is motion, and this motion is cyclic around a position of equilibrium. How many times have you touched a machine to see if it was running? You are able to tell by touch if the motor is running because of vibration generated by motion of rotational machine components and the transmittal of these forces to the machine housing. Many parts of the machine are rotating and each one of these parts is generating its own distinctive pattern and level of vibration. The level and frequency of these vibrations are different and the human touch is not sensitive enough to discern these differences. This is where vibration detection instrumentation and signature analysis software can provide us the necessary sensitivity. Sensors are used to quantify the magnitude of vibration or how rough or smooth the machine is running. This is expressed as vibration amplitude. This magnitude of vibration is expressed as:

Displacement – The total distance traveled by the vibrating part from one extreme limit of travel to the other extreme limit of travel. This distance is also called the “peak-to-peak displacement.”

Velocity – A measurement of the speed at which a machine or machine component is moving as it undergoes oscillating motion.

Acceleration – The rate of change of velocity. Recognizing that vibrational forces are cyclic, both the magnitude of displacement and velocity change from a neutral or minimum value to some maximum. Acceleration is a value representing the maximum rate that velocity (speed of the displacement) is increasing.

GE Bently Nevada
GE Bently Nevada is a leading provider of vibration
analysis instruments and software.
Various transducers are available that will sense and provide an electrical output reflective of the vibrational displacement, velocity, or acceleration. The specific unit of measure to best evaluate the machine condition will be dependent on the machine speed and design. Several guidelines have been published to provide assistance in determination of the relative running condition of a machine. It should be said that guidelines are not absolute vibration limits above which the machine will fail and below which the machine will run indefinitely. It is impossible to establish absolute vibration limits. However, in setting up a predictive maintenance program, it is necessary to establish some severity criteria or limits above which action will be taken. Keep in mind that guidelines are not intended to be used for establishing vibration acceptance criteria for rebuilt or newly installed machines. They are to be used to evaluate the general or overall condition of machines that are already installed and operating in service. For those, setting up a predictive maintenance program, lacking experience or historical data, similar charts can serve as an excellent guide to get started.

As indicated earlier, many vibration signals are generated at one time. Once a magnitude of vibration exceeds some predetermined value, vibration signature analysis can be used in defining the machine location that is the source of the vibration and in need of repair or replacement. By using analysis equipment and software, the individual vibration signals are separated and displayed in a manner that defines the magnitude of vibration and frequency. With the understanding of machine design and operation, an individual schooled in vibration signature analysis can interpret this information to define the machine problem to a component level.

Vibration monitoring and analysis can be used to discover and diagnose a wide variety of problems related to rotating equipment. The following list provides some generally accepted abnormal equipment conditions/faults where this predictive maintenance technology can be of use in defining existing problems:
  • Unbalance
  • Eccentric rotors
  • Misalignment
  • Resonance problems
  • Mechanical looseness/weakness
  • Rotor rub
  • Sleeve-bearing problems
  • Rolling element bearing problems
  • Flow-induced vibration problems
  • Gear problems
  • Electrical problems
  • Belt drive problems
Analyzing equipment to determine the presence of these problems is not a simple and easily performed procedure. Properly performed and evaluated vibration signature analysis requires highly trained and skilled individuals, knowledgeable in both the technology and the equipment being tested. Determination of some of the problems listed is less straightforward than other problems and may require many hours of experience by the technician to properly diagnosis the condition.

To learn more about vibration analysis and critical asset monitoring, contact Flow-Tech at 410-666-3200 or visit

Article abstracted from US DOE Operations & Maintenance Best Practices Release 3.0

Thursday, October 19, 2017

Centralized Gas Monitoring for Industry

Drager REGARD 7000
The Drager REGARD 7000 is a modular and highly expandable analysis system for monitoring various gases and vapors. Suitable for gas warning systems with various levels of complexity and numbers of transmitters, the Drager REGARD 7000 also features exceptional reliability and efficiency. An additional benefit is the backward compatibility with the REGARD.

For more information in Maryland or Virginia, contact Flow-Tech at 410666-3200 or visit

Check out the video below to learn more about the Drager REGARD 7000. Thanks for watching.

Monday, October 9, 2017

5 Myths of Dust Explosion Propagation

Fike explosion testing
Dust explosion propagation testing at Fike labs.
Abstracted from
"Dust Explosion Propagation: Myths and Realities"
by Fike Corporation

The unfortunate propensity of dust explosions to destroy entire facilities and claim lives has been reported in numerous past incidents.

Powder handling processes are often comprised of interconnected enclosures and equipment. Flame and pressure resulting from a dust explosion can therefore propagate through piping, across galleries, and reach other pieces of equipment or enclosures, leading to extensive damage.

While the ability of dust explosions to propagate has been widely recognized, some misconceptions lead to the false sense of security that explosion isolation is not required.

This post will enumerate, illustrate and unravel 5 common myths about explosion propagation. Download the full Fike White Paper here, or read it in full at the bottom of this post.

Myth #1: A large amount of dust is needed for an explosion to propagate.

Dust explosions do not need large amounts of fuel to propagate.

A 1 mm layer can create a dust explosion hazard in a typical room. The explosion only needed a 1/100 inch layer of dust on the ground to fully propagate.

Myth #2: A dust explosion starting in a vented vessel cannot propagate through connected pipes.

It is a common belief that protecting an enclosure, by means of venting or suppression, will affect explosion propagation in such a manner that no explosion isolation is needed at all. 

Although venting protects a vessel from the high pressures generated by an explosion, it does not necessarily prevent the explosion from being propagated through piping into other vessels.

Myth #3: A dust explosion cannot propagate against process flow. 

An argument also often heard is that a dust explosion cannot propagate against pneumatic process flow. 

An explosion is capable of traveling both with and against process flow, even over long distances.

Myth #4: A dust explosion weakens as it propagates.

Literature includes numerous discussions about explosion behavior in interconnected vessels. 

Experimental evidence has shown that explosions not only propagate, but become increasingly more damaging.

Myth #5: Small diameter pipes do not support dust explosion propagation.

Dust explosion propagation in small pipes has always been a controversial topic. The primary argument being that flame propagation is challenged due to heat loss to the pipe walls.

While conditions for dust explosions to propagate in relatively small diameter pipes are not yet fully established, their ability to propagate has been clearly demonstrated by several researchers.

Contact Flow-Tech with any questions regarding explosion protection testing, isolation valves, vents and systems at or call 410-666-3200.

Saturday, September 30, 2017

Campus Metering: Why Meter?

Instrumentation Energy Management
Schools, universities, medical centers and federal building
use instrumentation for energy management.

Energy and water managers have long known the value of metered data. With recent advances in energy and water metering and information systems resulting in increased functionality at lower costs, obtaining these data in a cost-effective manner is now a standard practice. Whether energy and water resource managers are trying to comply with legislated and mandated metering requirements, or looking to apply accepted building management best practices, such as utility bill verification or benchmarking, today’s metering technologies can provide the information needed to meet energy and water goals, save money, and improve building operations.

Metering of energy and water utilities has seen an increase in interest, application, and technology
Clamp-on flow meter
Clamp-on flow meter (Flexim)
advancement in both the private and the public sectors. One significant driver of this heightened interest is the ongoing modernization of the nation’s electric infrastructure with the move toward the smart grid and smart meters. Another significant driver, specific to the Federal sector, includes the legislative mandates for metering of Federal buildings.

The Business Case for Metering

The application of meters to individual buildings and energy-intensive equipment provides facility managers and operators with real-time information on how much energy has been or is being used. This type of information can be used to assist in optimizing building and equipment operations, in utility procurements, and in building energy budget planning and tracking.

It is important to keep in mind that meters are not an energy efficiency/energy conservation technology per se; instead, meters and their supporting systems are resources that provide building owners and operators with data that can be used to: 
Flow computer
Flow computer (KEP)
  • Reduce energy and water use
  • Reduce energy and water costs
  • Improve overall building operations 
  • Improve equipment operations
How the metered data are used is critical to a successful metering program.

Depending on the type of data collected, these data can enable the following practices and functions:
  • Verification of utility bills
  • Comparison of utility rates
  • Proper allocation of costs or billing of reimbursable tenants 
  • Demand response or load shedding when purchasing electricity under time-based rates 
  • Measurement and verification of energy project performance 
  • Benchmarking building energy use 
  • Identifying operational efficiency improvement opportunities and retrofit project opportunities 
  • Usage reporting and tracking in support of establishing and monitoring utility budgets and costs, and in developing annual energy reports. 
Most of the metered data uses listed above will result in a reduction in energy and water costs. The degree of cost reduction realized will depend on the unit cost of the energy and water being saved and on the effectiveness with which the site analyzes the data and acts upon its findings and recommendations. Examples of additional metering benefits can include:
Inline flowmeter
Thermal dispersion flow meter (FCI)
  • Supporting efforts to attain ENERGY STAR and/or green building certifications 
  • Promoting tenant satisfaction by providing information that tenants find useful in managing their operations 
  • Prolonging equipment life (and reducing capital investment requirements) and improving its reliability by verifying the efficient operation of equipment 
  • Assessing the impact of utility price fluctuations prior to or as they happen, allowing sites/agencies to address budget shortfalls on a proactive basis. 
Metering options will change in response to new material, electronic, and sensor development, as well as new and additional requirements for real-time data information. Future expansion of a metering system should be considered, as well as introduction of new metering and sensor technologies, based on the best available information, but be careful not to over design a system, thus unnecessarily increasing its cost.

Contact Flow-Tech with questions about improving your facilities energy management systems.  

Tuesday, September 12, 2017

ADMAG TI Series AXW Magnetic Flowmeter Maintenance Manual

ADMAG TI Series AXW Magnetic Flowmeter
ADMAG AXW Magnetic Flowmeter
The ADMAG AXW™ series of magnetic flow meters has been developed based on Yokogawa's decades-long experience in Magnetic Flowmeters. The AXW series continues the tradition of high quality and reliability that has become synonymous with the Yokogawa name.

The AXW series is ideal for industrial process lines, and water supply / sewage applications. With outstanding reliability and ease of operation, developed on decades of field-proven experience, the AXW will increase user benefits while reducing total cost of ownership.

Sizes are available from 500 to 1800 mm (20 to 72 inch.) with a wide liner selection such as PTFE, Natural hard rubber, Natural soft rubber, and Polyurethane rubber lining. Offering industry standard process connections such as ASME, AWWA, EN, JIS, and AS flange standards. A submersible version is also available.

This manual provides the basic guidelines for maintenance procedures of ADMAG TI (Total Insight) Series AXW magnetic  flowmeters.

In Virginia, contact Flow-Tech for any Yokogawa instrument requirement you may have. Call 804-752-3450 or visit