Operating Principles and Application of Vortex Flowmeters

Animation of vortices*

To an untrained ear, the term "vortex flowmeter" may conjure futuristic, potentially Star Wars inspired images of a hugely advanced machine meant for opening channels in warp-space. In reality, vortex flowmeters are application specific, industrial grade instruments designed to measure an important element of a fluid process control operation: flow rate.

Vortex flowmeters operate based on a scientific principle called the von Karman effect, which generally states that a fluid flow will alternately shed vortices when passing by a solid body. "Vortices" is the plural form of vortex, which is best described as a whirling mass, notably one in which suction forces operate, such as a whirlpool. Detecting the presence of the vortices and determining the frequency of their occurrence is used to provide an indication of fluid velocity. The velocity value can be combined with temperature, pressure, or density information to develop a mass flow calculation. Vortex flowmeters exhibit high reliability, with no moving parts, serving as a useful tool in the measurement of liquid, gas, and steam flow.

Photograph of vortices **

While different fluids present unique challenges when applying flowmeters, steam is considered one of the more difficult to measure due to its pressure, temperature, and potential mixture of liquid and vapor in the same line. Multiple types of steam, including wet steam, saturated steam, and superheated steam, are utilized in process plants and commercial installations, and are often related to power or heat transfer. Several of the currently available flow measurement technologies are not well suited for steam flow applications, leaving vortex flowmeters as something of a keystone in steam flow measurement.

Rangeability, defined as a ratio of maximum to minimum flow, is an important consideration for any measurement instrument, indicating its ability to measure over a range of conditions. Vortex flowmeter instruments generally exhibit wide rangeability, one of the positive aspects of the technology and vortex based instruments.

The advantages of the vortex flowmeter, in addition to the aforementioned rangeability and steam-specific implementation, include available accuracy of 1%, a linear output, and a lack of moving parts. It is necessary for the pipe containing the measured fluid to be completely filled in order to obtain useful measurements.

Vortex flowmeter
(Azbil)

Applications where the technology may face hurdles include flows of slurries or high viscosity liquids. These can prove unsuitable for measurement by the vortex flowmeter because they may not exhibit a suitable degree of the von Karman effect to facilitate accurate measurement. Measurements can be adversely impacted by pulsating flow, where differences in pressure from the relationship between two or more compressors or pumps in a system results in irregular fluid flow.

When properly applied, the vortex flowmeter is a reliable and low maintenance tool for measuring fluid flow. Frequently, vortex flow velocity measurement will be incorporated with the measurement of temperature and pressure in an instrument referred to as a multivariable flowmeter, used to develop a complete measurement set for calculating mass flow.

Whatever your flow measurement challenges, share them with a flow instrument specialist, combining your process knowledge with their product and technology expertise to develop effective solutions.

* Animation of vortex creation credit Cesareo de La Rosa Siqueira via Wikipedia.
** Photograph of vortices credit Jürgen Wagner via Wikipedia.

Providing New England Industry with Process Instrumentation, Valves, and Unsurpassed Service for Over 40 Years

PSI operates under one single mission: To provide specialty valves, instruments, control systems and mechanical products to industrial users throughout the Northeast, and to do so by providing unsurpassed customer service.

Covering the states of Maine, Vermont, Massachusetts, New Hampshire, Rhode Island, and Connecticut through offices located in Portland, Maine and Danvers, Connecticut, PSI is well situated to provide quick delivery, on-site services, and engineering support all through New England.

Piping Specialties, Inc. provides industrial valves, including ball, butterfly, gate, globe, safety relief, and control vales; and mechanical specialties including, steam traps, condensate recovery systems, steam water heaters, site level gauges, jet pumps, expansion joints, and modular pipe seals.

PSI Controls provides automated industrial and commercial valve packages that include quarter-turn and linear valves, pneumatic and electric actuators, limit switches and valve communications; and process instrumentation & controls including level, pressure, temperature and flow  instrumentation.

PSI Services provides installation of valve automation systems, valve repair, instrument repair, instrument calibration, turnkey systems and field support services.

Floating Roof Tank Spill Prevention

Floating Roof Tank Spill Prevention (Drexelbrook)

One of the most difficult and critical applications is measuring the high alarm or potential overfill condition on a floating roof tank containing liquid petroleum products such as crude oil or refined products such as fuel. It normally is comprised of a cylindrical steel tank equipped with an internal or external floating roof, that floats on the surface of the stored liquid. Floating roof tank systems are especially beneficial in eliminating the evaporative losses of the liquids. As opposed to a fixed roof tank there is no vapor space in the tank. This helps to reduce risk in highly explosive vapor environments. This is an extremely high cost of failure application, and one in which only the safest and most trusted products are accepted.

Drexelbrook's
Intellipoint

Safe operation of the tank farm relies on critical real time continuous level measurements of the liquids in the tank, as well as detecting when a high level condition exists. Products used in this application are typically required to meet the API 2350 Overfill Protection Standards, as well as SIL Safety Integrity Level performance standards to IEC 61508.

The challenges to reliably detect a high level condition on a floating roof tank are long sensor length requirements, and the variability of what is being measured. The floating roof may be dry in which case you need to detect the position of the physical metal roof. Or there may be a few inches of rain water or petroleum liquids on the roof. Measuring instruments need to determine very accurately, usually within a few millimeters, when the position of the floating roof has reached a high level alarm condition.

Drexelbrook's Intellipoint, with its unique floating roof probe, can accurately detect and alarm on the position of the floating roof or the presence of liquid under all these conditions. The safety Intellipoint is a SIL2 fully certified RF admittance point level switch with uncompromising reliability for the most demanding applications.  Drexelbrook has almost 60 years of RF admittance technology experience and is proud to offer this specialized product as the latest in its award-winning portfolio for the level market.

Product features include:

• Adjustable up to 15 feet, or 4.6 meters, to accurately control the alarm point. 
• A trip point accuracy of a few millimeters.
• Fully SIL2 certified to IEC61508. 
• Worldwide hazardous area approvals .
• Meets overfill protection standards API2350.
• A floating roof tank probe that is unique in the industry.

Refractometer Application for Wet Spinning of Alginate Fibers

Refractometer used for
wet spinning of alginate fiber.
(K-Patents) 

Alginates are biopolymers extracted from brown algae species such as seaweed. Extraction is performed from the harvested material by treatment with aqueous alkaline solutions. The extract is then filtered and the alginate salt is precipitated by the addition of calcium chloride or an acid. After purification, drying and milling, a water-soluble sodium alginate powder is produced. Alginates have found a variety of uses in different industries because of their unique properties. These materials have been extensively used in pharmaceutical applications as they are gel forming, non-toxic and highly absorbent.

The document below illustrates the use of industrial refractometers in the processing of Sodium Alginate. You can also download the full PDF of "Wet Spinning of Alginate Fibers" here.

Refractometer Application for Wet Spinning of Alginate Fibers from Piping Specialties, Inc and PSI Controls

Conval Clampseal Valve Seat Reassembly Instructions

Valve seat reassembly instructions for Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is seventh and final video in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

What is a Magnetic Level Gauge?

Magnetic Level Gauge (Penberthy)

Magnetic level gauges, also known as magnetic level indicators, are routinely used to provide a display of liquid level in tanks and other vessels. Their popularity stems from their high visibility from distances and non-invasive design which reduces the possibility of points and the risks of fugitive emissions.

"Mag Gauge" construction is fairly simple. A magnetic float, designed for the specific gravity of the material being measured, rides inside a vertical pipe on top of the process media. A gauge with magnetically coupled visual indicator is fastened to the pipe. As the media inside the pipe rises and falls, the visual indicator moves in the same fashion.

Magnetic level gauges are often employed in tandem with magnetostrictive, guided wave radar, or other measurement means to provide a reliable local display of liquid level, as well as an electrical signal that can be transmitted to recording instrumentation or controllers.

Magnetic level gauges features:

• Continuous level measurement
• Operable without electric power
• Direct visual tank fluid level indication, regardless of tank shape or profile.
• Wide range of operating temperature and pressure
• Breakage resistant construction
• Range of construction materials available to accommodate corrosive media
• Measuring indicators, switches, and transmitters mounted externally, without contacting the medium being measured.
• Low maintenance operation.
• Readable level indication from greater distance than glass sight gauges.
• Applicable to large fluid level ranges with a single instrument.

Magnetic level indicators are used widely in liquid level measurement and should be considered as a candidate for fulfilling those applications where the magnetic level gauge features fulfill the project requirements. There are many options available to customize the level indicator for each specific application. Share your application challenges with a product specialist, combining your process knowledge with their product application expertise to develop an effective solution.

Piping Specialties and PSI Controls

Piping Specialties was founded in 1975 with the mission of providing specialty valves and mechanical products and unsurpassed customer service to industrial users throughout the Northeast. Over the years our company has experienced steady, sustainable growth in both our customer base and product offerings. With offices in Danvers, MA and Portland, ME, we are geographically well-positioned to serve all of the Northeast.

PSI delivers our products and services through our 3 operating divisions:

• Piping Specialties: valves and mechanical specialties.
• PSI Controls: automated valves and process instrumentation & controls.
• PSI Services: valve automation, valve and instrument repair, calibration, and turnkey installation and field services.

Conval Clampseal Valve Seat Blueing/Lapping Instructions

Conval Clampseal^® Valves are much easier to renew than anything else on the market. This video is sixth in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Conval Clampseal Valve Seat Refacing/Resurfacing Instructions

Valve Seat Refacing/Resurfacing instructions for Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is fifth in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Increased Cycle Count Improves Operational Efficiency in Slurry Ore Mining Operations

Challenge

Long distance slurry pipelines for moving mineral concentrates over various elevations and long distances is often more economical than trucking or rail due to topography constraints and environmental concerns. To capitalize on these investments, the pipe sizes are maximized. Therefore, large-bore dependable valves are vital to the success of the slurry pipelines.

Under the same process conditions,
the competitor’s valve
underperformed and required
frequent maintenance due to erosion.

Three months after the main choke and choke loop press letdown stations were commissioned at a large copper-gold-molybdenum mining operation, ongoing repairs were required for all eight competitor valves. Valves in this position were expected to perform for at least 180 cycles without repair. These failures and leakage problems were caused by the valves’ integral seat design, which form a gap between the ball and seat allowing particles to enter the sealing area in the reverse pressure. This problem cost this customer an average of $800,000 to $1M per year in maintenance repairs.

Solution

Even with MOGAS’ 40-year history of successfully engineering large valves for the slurry transport market, MOGAS proposed to lease a test valve to be placed alongside a series of competitor valves.
In January 2013, a 36-inch, ASME 300 Class model CST-1 valve was installed in the  first loop of the control station. In this model’s proven bi-directional seat design, the seat maintains 100% contact with the ball in both normal and reverse pressures. This prevents build-up behind the downstream seat and ensures evacuation of solids around upstream seat during cycling.

Results

After one year the MOGAS
valve performed 818 successful
cycles—over four times the
cycle count required in this application.

One year later during decommission, the MOGAS valve was inspected. It had performed 818 cycles; far more than the 180 cycle count required in this application. The MOGAS valve was then removed and installed outside the loop, in the main choke station replacing the competitor valve, where it further performed 215 cycles for the next two years.

After three years of continuous operation, the MOGAS valve had successfully performed 1033 cycles. On inspection, the ball and seat were in good repair, so only the gasket and packing box were replaced and the valve was put back in to service.

Download the PDF of this case study from the PSI website here.

For more information, contact Piping Specialties, Inc. by calling 800-223-1468 or visit https://psi-team.com.

Reprinted with permission from MOGAS.

The Important Role of Valve Actuators

Actuator being positioned on large ball valve.
(Piping Specialties)

Valves are essential to modern industry. The prevalence of valves in engineering, process control, and manufacturing across the world is astounding, and each valve application requires it's own performance standard. Product safety, quality, and consistency is dependent on the proper selection of valves, whether ball, butterfly, gate or globe. Along with proper selection of the valve type, selecting the proper valve operator is critical for controlling the process, assuring quality, and protecting equipment and personnel.

Actuators are powered mechanisms that position valves between open and closed states; the actuators are controllable either by manual operators, or as part of an automated system where the actuator responds to a remote control signal. The valve actuator is as important to the valve, as the valve is to the industry in which it functions.

Thanks to actuators, multiple valves can be controlled in a process system in a coordinated fashion; imagine if, in a large industrial environment, engineers had to physically adjust every valve via a hand wheel or lever! It is completely impractical from a logistical and economic perspective. Actuators enable automation to be applied to valve operation throughout the facility.

Valve actuators serve as the interface between the control intelligence and the physical movement of the valve. The most obvious advantage of valve automation is risk mitigation, where, as long as the system is functioning correctly, critical calamities in either environmental conditions or to a facility can be pre-empted and quickly prevented.

Rack and pinion actuators.
(Flo-Tite)

Regardless of its power source, be it electricity, hydraulic fluid, air pressure, or other, all valve actuators share a singular purpose; to produce linear or rotary motion under the command of a control source. Depending on the design and settings of the actuator, valves can be closed, fully open, or somewhere in-between. Modern actuation technology allows for remote indication and control of valve position, as well as other diagnostic and operational information.

Pneumatic actuators utilize air pressure as the motive force which changes the position of a valve. Hydraulic actuators depend on non-compressible liquids under pressure to provide the motive force. Electric actuators, either motor driven or solenoid operated, rely on electric power to change valve position.

As automation continues to advance throughout every industry, manual valve operation makes less and less sense. Component integration, lower cost and universally accepted valve communications systems are becoming the norm. Simple, seldomly operated, basic valves are now outfitted with inexpensive automation packages that allow them to be monitored as part of the entire process control system.

Automated valves ready for shipment.

Thanks to their versatility, reliability, and technological advances, valve actuators provide safe and repeatable operation in critical processes all over the world.  Just as industries are the backbones of societies, valves are key building blocks to industrial processes, with actuators ensuring both safe and precise operation.

For information on valve automation, contact Piping Specialties by calling 800-223-1468 or by visting https://psi-team.com.

Conval Clampseal Valve Chamber REPACKING Instructions

Bonnet Chamber REPACKING instructions for Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is fourth in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Conval Clampseal Valve Chamber Unpacking Instructions

Bonnet chamber unpacking instructions for Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is third in a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Industrial Process Refractometers

Process refractometer
(K-Patents)

The ultimate focus of industrial refractometry is to describe the percentage of certain compounds in a final product. Refractometry, a combination of physics, materials, and chemistry, is the process which measures the composition of known substances by means of calculating their respective refractive indexes (RI). RIs are evaluated via a refractometer, a device which measures the curve, or refraction, resulting when the wavelength of light moves from the air into and through a tested substance. The unitless number given by the refractometer, usually between 1.3000 and 1.7000, is the RI. The composition of substances is then determined when the RI is compared to a standard curve specific to the material of the substance.

Common examples of industrial refractometry uses are measuring the salinity of water to determine drinkability; calculating the dissolved solids in liquor processing in pulp and paper production;  figuring beverages’ ratios of sugar content; and understanding the hydrocarbon content of motor fuels. Regarding pulp and paper, refractometry scrutinizes content of compounds in black and green liquor processing. Regarding food, refractometry has the ability to measure the glucose in fruit during the fermentation process. Because of this, those in food services know when fruit is at peak ripeness and, in turn, also understand the most advantageous point in the fruit’s “lifetime” to put it on the market.


Equipment manufacturers have developed numerous refractometer configurations tailored to specific use and application. Each has a set of features making it the proper choice for its intended application. Product specialists can be invaluable sources of information and assistance to potential refractometer users seeking to match the best equipment to their application or process.

Don't Overlook the Importance of Scheduled Calibration for Your Plant's Process Instrumentation

Calibration 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.

In 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 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.

Conval Clampseal Valve Inspection Instructions

Inspection of the Conval Clampseal valve.

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is second of a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Conval Clampseal Valve Disassembly Instructions

Conval Clampseal® Valves are much easier to renew than anything else on the market. This video is one of a series demonstrating how to service Clampseal valves.

https://psi-team.com
800-223-1468

Understanding How Control Valves Work

Understanding industrial control valve design and operation is very important if you work as a process engineer, a plant maintenance person, or if you design process control loops.

Control valves are used extensively in power plants, pulp and paper mills, chemical manufacturing, petro-chemical processing, HVAC and steam distribution systems.

There are many types, manufacturers, body styles, and specialized features, but the they all share some basics operating principles. The video below explains components, operation, and fundamentals.


Piping Specialties / PSI Controls
800-223-1468
https://www.psi-team.com

Top 3 Reasons to Specify the Conval Clampseal Gate and Globe Valves

1. Superior Rugged Construction - Conval valves are designed and built for extreme longevity. Features such as electroless nickel plated finish, complete material traceability of all wetted parts and yoke, instantly establish the quality of the Clampseal® Valve. The Clampseal® also has a pressure actuated backseat which provides maximum valve integrity by ensuring a positive internal stop for the valve stem and disc assembly. The actuated backseat extends packing life by securely isolating the packing from the pressure when the valve is fully open. Valves built forty years ago are still in service today.
2. In-Line Renewability - When inspection or servicing is required, Conval's in-line renewable valves do not need to be cut out (as do most other welded-in valves). The result is the shortest downtime and lowest life-cycle costs in the industry. A complete service, including a reground seat, new packing or stem replacement can often be accomplished in less than thirty minutes.
3. Renewal vs. Replacement - Renewing Clampseal® valves cost as little as 10% of the cost of replacing it. Renewing the packing is less than 4% of the cost of materials to replace a globe valve. In addition to the savings listed above, there are intangible savings from shorter shutdown time, which is considerable given that the cost of plant shutdown often exceeds the cost of equipment.

For more information on Conval gate and globe valves, contact Piping Specialties, Inc. by calling 800-223-1468 or visit https://www.psi-team.com.

Link-Seal Modular Seals, Century-Line Sleeves, Cell-Cast Disks Engineering Manual & Buyers Guide

Link-Seal Modular Seals, Century-Line Sleeves, Cell-Cast Disks Engineering Manual & Buyers Guide from Piping Specialties, Inc and PSI Controls