Showing posts with label Western Pennsylvania. Show all posts
Showing posts with label Western Pennsylvania. Show all posts

Level Sensors for Corrosive Liquids

Levelpro plastic level sensors
ICON Levelpro plastic level sensors.
Corrosive liquids can be found in just about every industry; food, metal finishing, water-waste water treatment, textile, automotive, to name just a few.  When it comes to selecting the correct sensor technology there are many different factors to consider.

Plastic level sensors are an excellent choice for corrosive liquid chemical applications.  Plastics, unlike metals, do not corrode; however, they can deteriorate and swell if the correct plastic is not used.

ICON Process Controls offers its Levelpro plastic level sensors for continuous level indication, as well as plastic level switches for point level notification.  There are many different factors to consider when selecting the right product for the application.

  • Chemical Liquid?
  • Concentration?
  • Temperature?

With this information a material of construction for the level sensor can be selected.  Next, it is important to understand other factors that contribute to the success or failure of the level sensor.

  • Is there particulate with the liquid?
  • Does the liquid create a film, or does it have a coating effect?
  • Does the chemical produce foam?
  • Is there sludge at the bottom of the tank?
  • Is the liquid agitated?

Once the information pertaining to the chemical and the type of sensor technology (continuous or point) is determined, ICON can recommend the most suitable product for the application.

An excellent level sensor for corrosive liquids is the 100 Series submersible level sensor.  The plastic level transmitter is available in PVC, PP and PVDF bodies, and comes standard with a corrosion-resistant PTFE jacketed cable and Kalrez O-rings.  The 100 Series submersible level sensors incorporate a weighted body which ensures the sensor sits at the bottom of the tank.  The plastic level transmitter has a ceramic sensing diaphragm that measures the head pressure of the liquid.  These level sensors are not affected by foam, vapor, condensate or turbulence, making them an excellent choice for many different applications.

If the chemical produces sludge then ICON would recommend a non-contact level technology such as the Ultrapro ultrasonic level sensor, or the Proscan radar transmitter.

For clean liquids the CFL Series continuous float is a reliable and economical choice.

ICON also offers a complete line of plastic level switches for point level indication.  These plastic switches are available in PVC, PP and PVDF materials, and the relay can be set to normally open or normally closed positions. Visit M.S. Jacobs at https://msjacobs.com for more information.

WIKA Phases Out PSD-30 and PSD-31 Pressure Switches, Replaced with PSD-4 Pressure Switch

PSD-4 Pressure Switch
The WIKA PSD-30 and PSD-31 pressure switches are currently being phased out, to be replaced with the newly updated PSD-4 pressure switch.

The model PSD-4 pressure switch represents the extensive development of the  PSD-30 pressure switch.  A high accuracy of 0.5 %, freely configurable output signals (PNP/NPN, 4-20 mA / 0-10 V), the 5:1 scalability of the analog output, in addition to outstanding self-diagnostics, make the PSD-4 an excellent automation solution for industrial machines, hydraulic systems, and pneumatic systems applications.

While the PSD-4 offers new features and functionality, pricing is comparable to that of the PSD-30 and PSD-31.  This new pressure transmitter offers customizable features, such as allowing the user to select the switch type and output signal, while offering a 5:1 turndown ratio.  Additionally, this transmitter is an economical solution for applications requiring local display with an analog output signal.  The PSD-4 provides an upgrade in quality and customizability without negatively affecting budgets.

During development of the WIKA switch family a high value was placed on a robust design and the selection of appropriate materials suited to machine-building applications.  For this reason the case and the threaded connection of the electrical connector are made from stainless steel.

For more information, contact M.S. Jacobs by visiting https://msjacobs.com or by calling 800-348-0089.

M.S. Jacobs: Dedicated to Service and Excellence in Process Control

M.S. Jacobs and Associates has been a leading manufacturer's representative and distributor of industrial instrumentation and controls since 1945.  Expanding from its original focus on the steel industry, MS Jacobs services and supplies products in all major industrial markets, including power generation, chemical processing, pulp and paper, oil and gas production, water and wastewater treatment, nuclear power, pharmaceutical, institutional, and alternative energy.

Remote Power Where You Need It

PowerGen remote power generatorDesigned for rugged and remote operation, the PowerGen remote power generator provides reliable electrical power supply to the most demanding and mission-critical loads. Based on Qnergy’s no-maintenance and highly reliable PCK series Stirling engines, the generator package can work seamlessly with a variety of fuel supplies, including: natural gas, propane, ethane, biogas, and multiple associated gas streams. By means of its flexible and modular design, this generator package can be tailored to provide a broad range of power output architectures to meet the electrical requirements of each specific site load.

What Makes Qnergy PowerGen Your Remote Power Solution?
  • Qnergy Stirling Engine
  • No Maintenance
  • Frictionless Piston
  • Multiple Fuel Sources
  • Zero Lubrication
  • Enclosed System
  • High Efficiency
Applications
  • Artificial Lift
  • Communication & SCADA
  • Monitoring, Security & Safety
  • Prime Power
  • Renewable Hybrid
  • Well Pad Automation
  • Cathodic Protection (ICCP

Wireless Hazardous Area Access Point Enclosures, RF Enclosures, and Antennas

The HazaLynk™ Series by Analynk incorporates a wide selection of wireless hazardous area devices to suit a variety of industrial applications. The product line includes hazardous area antennas, hazardous area access point enclosures, and hazardous area RF enclosures that simplify the process of installing field instrumentation, while meeting code requirements for hazardous classified and explosive environments.

For more information, contact M.S. Jacobs by visiting https://msjacobs.com or calling 800-348-0089.


Why Choose Displacer Level Transmitters Over Differential Pressure Level Transmitters?

DP level transmitter diagram
DP level transmitter diagram.
Many technologies have been available over the years have helped the process control industry with level measurement. From basic mechanical float-operated level switches, the process automation industry has been developing new technologies to make industry safer and more efficient.

An example of a "tried and true" technology that was commonly used in the process automation industry is the DP (differential pressure) level transmitter. First introduced in the 1950s, DP transmitters measures the hydrostatic (head) pressure of a liquid in a tank or vessel and interprets this as level, based on the density/specific gravity of the liquid and programmed in by the user. A newer, alternative technology to DP transmitters is the displacer level transmitter, a device also based on specific gravity. While they both are dependent on specific gravity, they are significantly different in areas of installation, accuracy, and maintenance requirement.

Application/Calibration Considerations
Displacer transmitter
Displacer transmitter
construction.
  • Infers Level vs. Direct Contact - DP transmitters use inferential measurement to determine level measurement from the hydrostatic pressure.  Despite requiring the specific gravity variable having to be programmed into the transmitter electronics, the level displacer transmitter is in contact with the process media and the level measurement is direct.
  • Time Required to Set up / Calibrate: DP transmitters requires time consuming and expensive calibration/re-calibration if any of the set-up parameters change or if the same DP transmitter is used on different materials in the same tank. Displacer transmitters only require two variables to be programmed (temperature and specific gravity), making it easier when running multiple products in the same tank. Furthermore, many displacer transmitters do not require liquid to be present for calibration. They are programmed (wet or dry) using software. A huge time and money saving over DP transmitters.
Mounting Considerations
  • Orientation and Tank Penetration - The physical mounting of DP transmitters is limited, which can in some situations can become downright problematic. DP transmitters require (2) side-mounted entry locations on the vessel or tank, with one having to be near the bottom. As a general rule, the fewer the entry points of a tank or vessel, the better (because of leakage). Tank bottom entries are all the more so concerning. Displacer transmitters are mounted to meet the requirements of the application and do not require a connection at the bottom of the tank.

Displacer transmitter
Displacer transmitter.
(Magnetrol)
Installation Cost
  • Consider Overall Installed Cost - While DP transmitters have a lower unit cost, adding ancillary components such as tubing and heat tracing can quickly "level" the installation cost playing field. Furthermore, don't discount the time cost savings when setting up, calibrating and re-calibrating displacer transmitters.

Temperature Range Considerations
  • DP transmitters have a normal operating temperature of up to 250°F, with an upper limit of 650°F when special options are specified.
  • Displacer transmitter can be used up to 850°F, very helpful particularly with level measurement in a hot oil separator application.

There are many options and variants to accommodate industrial level applications. Share your level application challenges with instrumentation specialists, leveraging your own knowledge and experience with their product application expertise to develop the most effective solution.

BTU Metering with Non-invasive, Clamp-on Ultrasonic Flow Meters

MS Jacobs BTU Metering
BTU Metering for HVAC
Energy Management
The modern business climate has, for some time now, been spooling up demand for accountability and, even more so, efficiency. Whether you think of efficiency as "doing more with less" or just avoiding the expenditure of financial, human, or natural resources the end result is the same and calls for similar prerequisites.

We live in a society of buildings, each with a mapped out function. Most buildings are predominantly occupied by people, bringing a requirement to maintain temperature, relative humidity, and air quality at levels of suitable comfort for human occupants. The energy consumption involved with providing that level of comfort stands as a bold line item in the operating expense ledger for any building. That is where accountability and efficiency come in. It is in the building stakeholders' interest to have knowledge regarding rates and quantity of thermal energy usage, as well as efficiency measures of delivered output per unit of input energy.
MS Jacobs BTU Metering
Installation of the BTU meter.
Typically takes about 4 hrs.

HVAC (Heating, Ventilation, Air Conditioning) primarily is an endeavor that generates and moves
thermal energy throughout an enclosed space. Commercially available technology now allows a building operator to accurately measure that movement of thermal energy throughout a system or building. The process is generally called BTU metering and has a number of justifiable benefits.
  • Real time equipment performance measurement.
  • Sub metering can indicate specific areas of consumption.
  • Ability to directly bill multiple tenants in a single building for their thermal energy usage.
  • Monitor and balance energy flows.
BTU metering essentially involves inlet and outlet temperature measurement of heat transfer liquids, along with their flow rate. While the principle is simple, the intricacies of the measurement methods and equipment accuracy can have a substantial impact on the accuracy, and thus the benefit, of the measurement data. Additionally, adding more instrumentation to an already complex system can create an additional on-going maintenance and calibration burden to retain the necessary levels of accuracy and function. Success at gaining the benefit of the performance data while minimizing the additional maintenance burden due to the instrumentation should be the goal.

MS Jacobs BTU Metering
Click for larger image.
One solution calls for the use of clamp on ultrasonic flow meters to measure liquid flow, coupled with temperature measurement in a single unit that will perform necessary calculations and provide output data in useful engineering units. An overarching benefit of the clamp on meter is its non-invasive nature, allowing its retrofit to in-place systems with no disturbance to existing piping. Here are some other characteristics of a highly effective BTU measurement unit:

  • No wear mechanism as part of the flow measurement unit
  • Traceable accuracy of flow and temperature measurements
  • Simple installation in new or retrofit applications without disruption to system operation
  • Reliable and maintenance free operation
  • Accurate measurement from near zero flow rate to maximum system flow
  • Stable sensing with no zero drift
  • Communications protocol to match building energy management system
  • Large storage cache for data, in case of communication failure
  • Common output signals, 4-20 ma or other, usable with selected ancillary equipment

Selecting the right equipment or instrumentation is the most important step along the path of adding measurement capability to increase efficiency. Without a solid stream of reliable data, useful decisions become difficult. Contact a product application specialist and share your goals and challenges. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

M.S. Jacobs & Associates

M.S. Jacobs & Associates is a leading manufacturer's representative and distributor of industrial instrumentation and controls in Western Pennsylvania, West Virginia and New York. MS Jacobs services and supplies products in all major industrial markets, including power generation, chemical processing, pulp and paper, oil and gas production, water and wastewater treatment, and nuclear power generation.

https://msjacobs.com
800-348-0089

Load Cells in Process Measurement

industrial process measurement load cells
Low profile low cells applied for tank and vessel
weighing and level indication.
Image courtesy Minebea Intec
In industrial application of process measurement and control, principles of the physical sciences are combined with technology and engineering to create devices essential to modern high speed, high accuracy system operation.

Load cells are the key components applied to weighing materials in modern processing. Load cells are utilized throughout many industries in process weighing operations. In application, a load cell can be adapted for measurement of items from the very small to the very large.

In essence, a load cell is a measurement tool which functions as a transducer, predictably converting force into a unit of measurable electrical output. While many types of load cells are available, the most popular cell in multiple industries is a strain gauge based cell. These strain gauge cells typically function with an accuracy range between 0.03% and 0.25%. Pneumatically based load cells are ideal for situations requiring intrinsic safety and optimal hygiene and, for locations without a power grid, there are even hydraulic load cells, which function without need for a power supply. These different types of load cells follow the same principle of operation: a force acts upon the cell (typically the weight of material or an object) which is then returned as a value. Processing the value yields an indication of weight in engineering units. For strain gauge cells, the principle of deformation applies, where extremely small amounts of deformation, directly related to the stress or strain being applied to the cell, are output as an electrical signal with value proportional to the load applied to the cell. The operating principle allows for development of devices delivering accurate, precise measurements of a wide range of industrial products. Advantages of load cells include their longevity, accuracy, and adaptability to many applications, all of which contribute to their usefulness in so many industries and applications.

Share your process weighing challenges with product application specialists. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Closed Loop Electronic Pressure Controller

electronic pressure controller
Electronic pressure controller provides closed loop PID
control of outlet pressure.
Image courtesy of Rotork Instruments - Fairchild
The control of pressure in a line, tank or other vessel is a common operation found in the process control field. Many pressure regulators are fully mechanical, with counterforce mechanisms used to set an equilibrium point for the regulator. While these devices are effective, they lack the level of functionality available in an electronically controlled device.

Rotork Instruments, as part of their Fairchild brand, offers a series of electro-pneumatic pressure controllers that have built in PID closed loop microprocessor control utilizing a remote analog or digital setpoint signal. The electronic controller regulates feed and bleed solenoid valves to control pressure in the signal chamber of the booster section. Outlet pressure is measured and used as a feedback signal to the controller to provide accurate control of the outlet pressure. The device functions as a volume booster and I/P transducer.

Any of the devices can be controlled from the onboard keypad or a remote signal. A remote pressure sensor line can also be used with the controller to derive the feedback signal from further downstream from the instrument. This is helpful in eliminating pressure drop effects over the distance from the controller to an identified process point. The remote sensing also can improve system response. Adding the remote sensing is simple, just remove the factory installed plug and install an adapter that facilitates a line connection.

The various models are available with volume booster sections rated for 1 to 700 SCFM. More detail is found in the specification sheet provided below. Share your pressure control challenges with process measurement and control specialists. Leverage your own knowledge and experience into an effective solution with their product application expertise.


Duplex Basket Strainer

duplex basket strainer with changeover diverter valve
A duplex basket strainer allows continuous process flow
when strainer basket requires cleaning.
Image courtesy Fabrotech
Liquid processing systems of many types and application require protection from particulate matter in the flow path. Often, there are mechanical components that cannot tolerate particulate matter greater than some maximum diameter. Pumps, valves, sensors, and other specialties can experience accelerated wear and tear, even clogging, from particulate matter entrained within the liquid flow.

Once the maximum particulate diameter has been determined for various portions of the system, a plan can be implemented that provides a properly sized and configured device in place to remove particulates larger than the greatest allowable size. It is conceivable that identifiable parts of a system will have differeing protection requirements, resulting in the use of several or many different filtration elements throughout the system. Filtration units can range from very small inline filter units protecting a single instrument, to large centralized high flow rate units protecting extended portions of the system.

A basket strainer will be an appropriate choice for many applications. Coordination of strainer housing connection size and type, along with design flow rate and pressure drop are in order. The materials of construction for the housing, strainer basket and other wetted parts should be evaluated for suitability with the process media. A final consideration is the holding capacity of the strainer basket itself. Too small a strainer will lead to a service frequency for cleaning that can prove cumbersome for operating personnel.

Regardless of the type of strainer or filter used, a key consideration is whether the system can be temporarily shut down, or the filter bypassed, while replacement or cleaning of the filtration element is accomplished. A basket strainer, one of several types of liquid filtration devices, is available in both simplex and duplex variants. A simplex basket strainer functions as a single inline unit, requiring flow stoppage or bypass when the basket becomes clogged with debris. The changeover time may not be long, but some processes cannot tolerate any downtime. A duplex strainer is comprised of two simplex strainers incorporated into a common housing. An inlet chamber and diverting valve selects which strainer basket will process the liquid flow, while isolating the other. Changes in pressure drop through the device can be used to signal when it is time to switch operation between the strainer sections.

Fluid filtration is an important part of keeping a process in operation, reducing wear and tear on piping system components and equipment. Share your process fluid filtration challenges and requirements of all types with application specialists. Leverage your own process knowledge and experience with their product application expertise to develop an effective solution.

Installation Basics for Ball Valves

three piece industrial ball valve
Three piece industrial ball valve, manually operated
Image courtesy of Duravalve, Inc.
Ball valves are characterized by their closure mechanism. Most often, a ball valve has a spherically shaped fabrication (ball) that is inserted in the fluid flow path. The ball has an opening through its center, often circular in cross section and matching the diameter and shape of the connected pipe. The ball is contained within the body of the valve and rotated around its central axis by torque applied to the stem. The stem, which extends through a seal to the exterior of the valve body, can be manually or automatically controlled via several methods.

During valve operation, the ball is rotated through a ninety degree arc from a fully closed to fully open position. When fully closed, the opening in the ball faces the sidewalls of the valve body and is cut off from the fluid by seals that secure the ball in place and prevent fluid flow around the ball. As the valve stem is rotated toward the open position, the cross sectional area of the opening is increasingly exposed to the fluid flow path until the open area through the ball is aligned with the flow path in the fully open position.

Here are some general installation and removal guidelines for ball valves.

  • Verify whether the valve is unidirectional or bidirectional. If valve function is limited to a single direction, make sure the inlet and outlet ports are properly oriented to the piping system flow direction.
  • Adequate access for handle movement, along with an operator's hand, should be confirmed prior to installing the valve.
  • Ball valves will function in any orientation.
  • If automated with an actuator, maintain sufficient clearance around the valve and actuator to provide adequate maintenance access.
  • Keep the installation area free of debris and dirt. Protect any valve parts that are removed or are awaiting installation. Avoid introducing any foreign matter, dirt or debris into the valve.
  • Valves may have any of a number of connection methods, including threaded, flanged, or socket weld. Disassembly of the valve may be appropriate when installing some types, especially socket weld. Care should be taken to avoid any damage to the ball surface, seals, or sealing surfaces. Scratches and nicks can produce leakage when the valve is reassembled.
  • If disassembling a currently installed valve, verify that the piping system is not under pressure prior to starting. Cycle the valve through open and closed positions a couple times to relieve any pressure that may be retained in the valve body.
  • Follow all manufacturer recommendations for applied torque on any fasteners.
  • When a ball valve is disassembled, for any reason, it may be a good time to replace seats.
  • Leak check final installation. Tighten packing gland nut to eliminate leaks at the stem.
These are general recommendations. In every instance, a review of the valve manufacturer's specific instructions prior to starting installation or service is good practice. Share your fluid control challenges with industrial valve specialists. Leverage your own knowledge and experience with their product application expertise to develop effective solutions.

High Density Signal Conditioners

microblox signal conditioning module
MicroBlox™ signal conditioning modules offer broad
functionality in a very compact package.
Image courtesy Acromag
Signal conditioning is a common function needed for proper operation of data acquisition or process control systems. The general purpose of signal conditioning is to convert an input signal of one type to an output signal of another, completing a usable path of information from signal generating device to signal using device. With many control and data acquisition systems employing numerous input signals from diverse sources and instruments, a control panel benefits from having a consolidated, adaptable means of performing all the required signal conditioning while occupying a minimized footprint in the panel.

The microBlox™ line of signal conditioners, from Acromag, provides a broad range of signal conditioning functionality in a compact and rugged industrial package. The microBlox™ line of signal conditioners provides a wide array of useful features, broad range of I/O signal compatibility, and a very compact high density footprint. The input modules offer screwless mounting in a choice of backplanes accommodating up to 16 channels. Functions included transmitter, alarm, and signal conditioner.

The variety of available models, some with economical precalibrated ranges, is extensive. The module construction, with its overmolded circuitry, provides resistance to dust, moisture, vibration and shock. The most valued capability of microBlox™ input modules is their Bluetooth connectivity. Mobile devices running either the Android or Apple versions of the Agility app can communicate with enabled modules to perform setup and configuration, diagnostic and troubleshooting functions. Input polling and trending is also possible using the app.

More technical data, illustration and description of the microBlox™ signal conditioners is included below. Share your signal conditioning and I/O challenges with a a product specialist. Leverage your own process knowledge and experience with their product application expertise to develop effective solutions.


Thermoplastic Industrial Ball Valves

thermoplastic floating ball valves for industrial use
Thermoplastic ball valves, TBH Series.
Image courtesy Hayward Flow Control
Ball valves are a mainstay of fluid control
throughout many industries. Like most valve types, the ball valve is named for its closure mechanism. A spherical shaped element is placed in the fluid flow path, with the ability to rotate its position around an axis. The axis is a shaft or other device that connects to an actuator on the exterior of the valve. The actuator can be a simple handle or an element of a valve automation system. The “ball” in the ball valve has an opening through its center, usually round to mimic the shape of the connected pipe. As the ball is rotated, the opening aligns with the inlet and outlet of the valve body, allowing fluid to pass. A counter-rotation that aligns the port (opening) with the sides of the valve body, away from the flow path, stops the fluid flow. A seat between the exterior surface of the ball and the containing valve body prevents fluid from flowing around the ball.

The basic ball valve design centers around either a floating ball or trunnion mounted ball. A floating ball valve uses the body and the seats to hold the ball in place, with the connecting shaft serving primarily as the rotating mechanism. This design can provide bidirectional closure, since the fluid flow seats the ball against one of the sealing surfaces. A trunnion mounted ball valve has positioning support pins that mate with machined portions of the valve body to hold the ball in place and serve as the axis of rotation. Trunnion valves are available in sizes larger than those of the floating ball design.

Various common and exotic metals are routinely used for body and internal construction. Thermoplastic ball valves are an alternative that provides high levels of corrosion resistance to the media, as well as the surrounding environment.

Typical applications for thermoplastic ball valves:

  • Municipal waste and water treatment
  • Clean water technology
  • Chemical transfer and processing
  • Aquatic and animal life support systems
  • Mining and mineral processing
  • Metal plating
  • Marine
  • Pulp and paper
  • Landfills and environmental infrastructure
Some detailed information about thermoplastic ball valves from Hayward Flow Control is provided below. There are more variants to fulfill a wide band of applications. Share your fluid control challenges with a process control specialist and leverage your own knowledge and experience with their product application expertise to develop an effective solution.



Pre-Assembled Self-Regulating Heating Cable Solves a Range of Freeze Protection Challenges Quickly

self regulating heat cable with termination
Preconfigured and terminated heat cable, self regulating,
can speed project completion.
Image courtesy BriskHeat Corp.
Heat tracing a pipe, from start to finish can be time consuming. Selecting the various components, starting with the heating cable itself, extends through termination kits, controllers, mounting hardware and other electrical hardware needed to put the heating system in operation. BriskHeat has a product that, for many applications, offers a very simple and quick solution.

Pre-assembled self regulating heat cable is available in two voltage ranges, two watt densities, and prefabricated lengths up to 150 feet. Each cable is terminated at each end, saving the installer time. The cable is flexible enough for a spiral installation or to wrap around valves in the piping system. The self regulating aspect of the cable negates the need for a controller and power switching devices. Assemblies targeted for 120 volt applications are provided with a factory installed plug. The 208-277 volt cables will arrive with bare wire leads for installation of a customer provided connector. The cable can be easily installed using fiberglass or aluminum tape. Suitable insulation applied over the finished work will improve the performance of the heating system.

Share your heat trace and freeze protection challenges with industrial heating specialists, leveraging your own knowledge and experience with their product application expertise.



Silicone Rubber Heating Blankets


Electric heaters provide an effective and directed method in which heat can be delivered to a surface. The application of an electric heating solution is compartively simple and does not generally require a large amount of supoorting infrastructure, as is the case with fluid based heating systems. Electric heaters for industrial and commercial applications are available in a vast range of types, materials, and forms. The silicone rubber heater is one form that delivers users some unique application options.

A silicone rubber heating blanket is essentially a rugged but flexible rubber sheet with heating wire embedded within. Stock sizes are available, but the basic design enables manufacturers to craft custom sizes to meet very specific customer requirements. The distinct advantage of silicone rubber heating blankets is their flexibility. The resistance heater wires are encased in a silicone rubber sheet, providing the ability to wrap the assembly around an object or manipulate it into a close fit with the target of a heating application. The silicone rubber encasement also provides a high level of protection for the heater wires from impact, moisture, and some chemicals. The products are delivered with ready made connections or customized terminals to suit project needs.

The watt density of the heaters can be specified to provide a good match between the delivery of heat and the need for it. Electric heat can also be regulated by an external power controller to maintain very close temperature control. Custom shapes and configurations can be manufactured to order, and on board or remote controllers provided. Pressure sensitive adhesive is a common option that facilitates the installation of the heater assembly to a part or vessel.

The maximum application temperature is in the range of +450°F (+232°C). These heaters are a useful selection option for a large range of operations demanding heat to be applied directly to a surface, object, tank, drum, or other vessel. Share your industrial heating challenges with product specialists and leverage your own knowledge and experience with their product application expertise for the best match up between heater technology and your application.

Use of Thermal Dispersion Flow Switches for Pump Protection

thermal dispersion flow switch
Model TD2 Thermal Dispersion Flow Switch
Image courtesy Magnetrol
Thermal dispersion flow switches use an operating principle similar to that of a thermal mass flow meter. Moving fluid carries heat away from the probe tip reducing the temperature difference between a heated resistance temperature detector (RTD) and a reference RTD. Unlike a flow meter, a thermal dispersion switch operates with setpoints, comparing the detected flow rate to the setpoints and controlling a relay or other digital output in response. Manufacturers will refer to the switch being in “alarm” at set point. How the relay is wired (NC-CO or NO-CO) depends on the needs of the application.

High or low flows can be detected by thermal dispersion switches. While thermal dispersion flow measurement technology is applicable for gases and liquids, pump protection is the subject of this post, and reference will be limited to liquid flows and low flow detection.

Running pumps with inadequate liquid throughput is well recognized as a source of excessive wear, parts damage, cavitation and downtime due to repair. The cost of replacement parts, repair labor and lost production time can ramp up very quickly.
Monitoring liquid flow rate and triggering an alarm or pump shutdown to prevent damage has substantial benefit, even in a system of comparatively modest size.
There are many technologies that can measure liquid flow and function as part of a pump protection scheme. Flow meters can be used, but a continuous flow measurement may not be needed for the application. Flow meters typically are more costly than flow switches.

Mechanical flow switches are an alternative. Prior to the availability of electronic controls, they were generally the only method employed. They use a mechanical operator, driven by liquid flow, to actuate a relay. Typically, a vane or paddle is in the flow stream and swings in the direction of the flow. When the vane moves a predetermined distance, a magnetic sleeve or other device rises to draw the magnet in to actuate the switch. Moving parts are subject to wear, possible jamming and increased maintenance over time. Viscous liquids or those that may accumulate deposits on the operating mechanism can decrease reliability of the switch. A mechanical flow switch may be desirable if there is limited on-site power. In terms of the installation, the pipeline must be horizontal.

Vibrating forks and ultrasonic gap switches are other technologies employed for pump protection. It is inherent in these technologies that the presence or absence of liquid at the sensor location is all that is detected, not actual fluid flow. They are unable to detect decreasing flow rates, and their "gap" at the sensor creates opportunity for plugging or fouling with some liquids. Common applications for these switches are sumps or wet wells. Dual ultrasonic gap switches have pump control modes where the unit performs auto-fill or auto-empty as needed. 

Thermal dispersion flow switches deliver a robust feature set and application flexibility.
  • No moving parts
  • Low maintenance burden 
  • Range of probe types to accommodate water or more viscous liquids 
  • Installation in horizontal or vertical lines
  • Variety of mounting types and insertion locations 
  • Optional remote mount electronics
  • Hot tap options available
  • Low flow detection as opposed to dry pipe 
  • Current output for trending and fault indication
  • Temperature compensation to reduce set point drift under varying operating temperatures 
Probe Types

The standard probe design offered by thermal dispersion switch manufacturers is a twin tip construction to house the sensors. The twin tip is essentially two tubes welded to the end of the probe that are in the process liquid.

Twin tip probes can be beneficial as multiple manufacturers have similar designs. It has a very high pressure rating and is available in a variety of construction materials.

A unique design that may be preferred for liquid applications is the spherical tip probe. The lack of pins at the end of the probe eliminates plugging in viscous applications while the thin wall allows increased sensitivity with the process liquid. With pressure ratings up to 600 psig (41 bar) and standard 316 stainless steel material of construction it is suitable for most pump applications.

Electronics

The electronics for the thermal dispersion switch can be integral to the probe assembly or remotely located, enclosed in an explosion proof or other suitable housing. Wiring is simplified with the terminals easily accessible without removal of the bezel or any circuit boards. Along with the ease of installation come many diagnostic features incorporated in the microprocessor based electronics.

A useful diagnostic feature in the electronics is the current output. It is not a linear 4-20 mA output, similar to a flow meter, but the current will act as a live signal that varies with heat transfer. For example, in a low flow condition the current may be 8 mA and at normal flows 12 mA (output varies for each application). The current will be repeatable for a given low flow set point. If there is turbulence in the line, possibly being caused by a closed valve with the pump still running, the sensor will see this turbulence as a higher flow rate than what is actually occurring. The live signal allows the operator to monitor conditions to which the sensor is exposed and possibly develop custom diagnostics for the fluid system.

Along with the trending capabilities of using the current output, this output will also go low or high when a fault condition occurs according to NAMUR NE 43. For pump applications where a low flow alarm is desirable, the current will fall to less than or equal to 3.6 mA during the fault. The microprocessor based electronics monitor for any open circuits or flow signal that goes out of range. Without a microprocessor, the flow switch could be subject to more noise, have drift issues and need more frequent calibration to maintain the set point.

The user also has the option to select a window in the housing of the electronics. This window allows viewing of the LEDs to show normal operation (relay energized), alarm/set point (relay de-energized) and fault conditions (relay de-energized). Switch and process operation can be confirmed locally at a glance.

Because the principal of operation of thermal dispersion switches is temperature dependent, temperature compensation is provided in the electronics circuitry. Temperature compensation will reduce set point drift under varying operating temperatures.

Pump Installations

Both positive displacement and centrifugal pumps have performance curves to maximize efficiency. There is an ideal combination of differential head and flow rate that will provide the best results. If monitoring the differential head, a thermal switch can be set up to shut the pump down when it is operating below the ideal flow rates. Worst case scenario, the thermal switch is installed to verify there is liquid flow to prevent excessive wear or failure.

Installing the thermal switch in either the suction or discharge piping is acceptable. It is important to install in a location where the sensor tip will be exposed to liquid movement, especially in the case of a partially filled pipe. When field calibrated, which is most often the case for thermal switches, it is not necessary to install at the centerline of the pipe. As long as the probe is far enough into the pipe to see liquid movement, it will provide repeatability at the given flow rate. A quarter to half way into the pipe is common.

Installing a few diameters away from the pump will reduce the impact of excess turbulence. Turbulence may cause the switch to sense higher flow rates than what is actually occurring inside of the pipe. Movement of liquid due to turbulence can theoretically create as much heat transfer as the liquid flow itself. The aforementioned current output is a helpful diagnostic feature in more difficult installations.

Summary

Thermal dispersion switches are used in pump protection applications ranging from standard water to high viscosity liquids. There are unique sensor designs for each individual application, including the popular spherical tip, low flow bodies and high temperature/pressure probes. The multitude of probes in conjunction with the advanced electronics make thermal dispersion switches a competitive technology for pump protection.

Share your fluid flow challenges with process measurement specialists. Leverage your own knowledge and experience with their product application expertise to develop effective solutions.

Process Measurement and Control Devices for Corrosive Environments

all plastic industrial process measurement corrosion resistant pressure gauge
All plastic corrosion resistant pressure gauge.
Image courtesy ICON Process Controls
ICON Process Controls specializes in corrosion resistant industrial fluid handling process control equipment, offering industry the most complete line of instrumentation products in an all plastic form supported by the largest inventory in North America. Applications for corrosion resistant instrumentation and controls are found throughout...
  • Municipal and industrial water and wastewater treatment
  • Bulk chemical storage, handling and production
  • Steel processing
  • Metal Finishing
  • Chemical Dosing Skids
  • Food and Beverage processing and production
The ICON product line handles tasks for measuring and controlling flow, level, pressure, and temperature in environments that are otherwise challenging or corrosive to other process instruments. Their unique all plastic construction makes the ICON equipment and instruments particularly well suited to the harshest industrial environments.

For information about the complete line of corrosion resistant industrial fluid handling process control equipment from ICON, reach out to the process control experts at MS Jacobs. Share your process control challenges and leverage your own process knowledge and experience with their product application expertise to develop effective solutions.


Measurement and Control Products for the Shale Gas Industry

steel shale gas pipeline with valve
M.S. Jacobs provides measurement and control solutions
to the shale gas production and processing sectors.
Several areas of North America are involved with the extraction of shale gas resources. The Marcellus Formation, one of the largest shale gas production areas, is located beneath much of the coverage area of M.S. Jacobs & Associates. A substantial portion of the company's product lines have application potential throughout the layers of the industry.

The Gentherm Global Power Technologies TEG (thermo-electric generator) is a product M.S. Jacobs provides for “upstream” use on the production well pad. It provides a reliable source of electric power at off-grid locations and is preferred because of its reliability and operating principle. A TEG has no moving parts and requires little maintenance. A thermoelectric generator converts heat directly into electricity. As heat moves from a gas burner through a thermoelectric module, it causes an electrical current to flow. Thermoelectric generators are a preferred source of power in areas without reliable and abundant sunshine for photovoltaic production of electricity.

Another source of remote power are the Stirling Engine driven generators from Qnergy. Operating on any combustible fuel, these systems deliver electric power efficiently and require no maintenance. The Qnergy power units are fuel agnostic and insensitive to gas content, able to run on gas with variable caloric content.

M.S. Jacobs is also involved with solutions for midstream operations. Flexim ultrasonic clamp-on flowmeters serve as check meters at midstream processing facilities and compressor stations to measure large volumes of gas. They are also being used to help balance the load to the compressors. Other applications are on gas storage wells that are filled in the summer and pumped out in the fall-winter, taking advantage of the bi-directional measurement capability of the meter.

M.S. Jacobs also provides Magnetrol level controls and Orion visual level indicators for various level applications as well as valves and controls on other midstream and downstream applications. A primary partner to many processing companies, M.S. Jacobs provides experience, application expertise, local inventory, and ongoing support.

Share your process measurement and control challenges with application specialists, leveraging your own knowledge and experience with their product application expertise to develop effective solutions.

Expansion Joints in Process Piping Systems

Expansion joints relieve stress on process piping
Expansion joints accommodate the movement in piping systems
due to a number of real world factors.
Image courtesy General Rubber Corp.
Piping systems of any size require consideration of stresses placed upon the system by movement resulting from a number of possible factors. In some cases, the movement is vibratory and related to the operation of connected machinery. Another common case is the expansion and contraction of piping sections due to thermal effects.

Process piping can have substantial stress applied due to thermal expansion of the piping material itself. This is especially evident when portions of the process piping are fixed in position by their mounting method. Allowances must be made for expansion of the piping material in the installed location. The design criteria will include factors that impact the expansion of the piping components, as well as the relationships between the piping and elements of their supporting structures. Expansion can produce substantial movement of pipe sections which must be accommodated by the supports and the piping itself.


One manufacturer, General Rubber Corp., manufactures a wide range of expansion joints for process piping systems of almost any size. Their expertise, acquired over many years in the field, is reflected in the numerous product variants available to meet every application condition.

Share your process piping challenges with product specialsts, leveraging your own knowledge and experience with their product application expertise to develop effective solutions.